Author Topic: FIXED: 89 TBI 318 idles fine, nearly dies with slight throttle  (Read 856 times)

0 Members and 1 Guest are viewing this topic.

Offline benzdiesel

  • Newbie
  • *
  • Posts: 21
  • Gender: Male
FIXED: 89 TBI 318 idles fine, nearly dies with slight throttle
« on: December 20, 2019, 08:58:49 pm »
I'm sure problems like this have been discussed before, but I've checked the previous threads and haven't found a solution yet. Hoping for some advice.

I've got an '89 Ramcharger with the 318, that will start and idle without much trouble. One cylinder misses every once in a while but nothing major or unexpected given the age. I'd say it idles pretty smooth all told.

As soon as I push the accelerator any at all, it immediately falls flat, choking and stumbling and almost dying but usually not actually doing so. The RPM drops and it sounds like it's running on about half or less of the cylinders. It will continue running this way as long as you hold your foot in that position, it never improves or changes once it starts missing that way as long as you don't move your foot. This happens in Park, Neutral, and also while driving -- so I don't drive it anymore, I don't need it dying in traffic.

If you take your foot off and let it idle it generally comes back about like it was before. If you go on and accelerate harder, it quits choking and dying and starts running -- but not quite as smoothly, it still seems pretty rough and like it could be missing part of the time.

There are several signs that it's running rich. The exhaust smells heavy and gassy, the fuel mileage has dropped from terrible to unbelievable, and the only code in the computer besides 12, 37, and 55 (all of which can be ignored) is 52 which seems to be an O2 sensor reporting a rich condition (but I know that doesn't mean the O2 sensor is bad, just that the reading is out of spec possibly due to something else.)

The ignition components (wires, plugs, coil, cap, rotor) were changed recently enough to feel confident in them, and last time I checked the fuel pressure I saw nothing concerning.

Because the problem seemed related to throttle position rather than any load characteristics on the engine, I figured throttle position sensor was the most likely issue, I figured it probably had a dead spot in it that was not making contact and thus not giving the off-idle fuel that was needed, so I just installed a new one tonight; made zero difference.

Almost all the threads say to use a timing light and look at the fuel injector pattern. I hooked up the timing light but I can't see anything I'd describe as a cone, a spray, or any pattern at all looking down into the throttle body under the two dome-shaped things that I think are the injectors. I do see some liquid fuel sloughing down the back wall of the throttle body chamber in a fairly even cascade, but I can't spot any fuel vapor in the "air" between the injector and the air intake flaps. Most threads say check it with the timing light but don't say any more specifically how, and this is not a light that has any sort of adjustment on it so if the problem is I'm not timed in sync with the fuel, I don't believe I've got any way with the tool I have to adjust that way. I'm putting the pickup on the #1 plug (front driver's side.)

Other than the fact that the TPS was the most likely suspect and made no difference, and that the fuel dripping down the back wall of the throttle body might suggest that the injectors are shot, I don't quite know what to check next or how. I gather 02 sensors require a scope to verify they're sending the proper signal, it's nothing you can check with a multimeter... I own a bench scope but not an automotive one and I'm not sure I can easily tote the electronics one outside to the truck or if it would even give the necessary information when I got done.

I appreciate any suggestions. I'll try to carry them out but I may have to ask follow up questions to figure out how to do so. A lot of the threads where issues like this have been discussed went over my head in a hurry. I've got enough parts swapping and maintenance experience to get a lot of things done, but not so much on the diagnostic side, especially where TBI is concerned.
« Last Edit: May 15, 2020, 10:41:33 am by benzdiesel »
~Michael~

89 Ramcharger 318
87 Mercedes 300SDL
96 Grand Marquis
97 Acura CL
04 Trailblazer
10 BMW X5 35d

RamChargerCentral

  • Advertisement
  • ***

    Offline DODGEBOYS

    • DODGEBOYS.NET / RCC Signiture Police
    • RCC Addict
    • ********
    • Posts: 26576
    • Gender: Male
    • 45yr ASE Master Mechanic [Electronic Diagnostics]
      • DODGE TRUCKS @ DODGEBOYS.NET
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #1 on: December 20, 2019, 09:59:02 pm »
    if you read even some of the info on here you would have known that the 1988 to 1991 TBI trucks have really bad drive ability problems , with most stemming from the connectors at the back of the right valve cover to the PCM connector , also have you pulled the CODES = procedure link below

    https://ramchargercentral.com/electrical/dodge-codes-pre-95/
    put your truck info HERE
    MOPAR TO YA!!!!!! AARON HOWORD TOWNSEND / SLANTEDMIND---GOD BLESSDODGEBOYS FSM STORE
    [email protected]
    former Parts Mgr & A1 Tech @ Pete's Chrysler -Plymouth
    DO NOT use the site IM,s to contact me  l have them turned OFF

    Offline benzdiesel

    • Newbie
    • *
    • Posts: 21
    • Gender: Male
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #2 on: December 20, 2019, 10:31:28 pm »
     ??? Yes, I pulled the codes by cycling the ignition three times and counting flashes; I mentioned them in my original post:

    ...the only code in the computer besides 12, 37, and 55 (all of which can be ignored) is 52 which seems to be an O2 sensor reporting a rich condition (but I know that doesn't mean the O2 sensor is bad, just that the reading is out of spec possibly due to something else.) ...


    I'll see what I can do with the connectors and contact cleaner tomorrow in the daylight and advise if there's any change.

    Threads I read before posting:
    https://ramchargercentral.com/vehicle-help/some-tips-on-posting-for-help/

    https://ramchargercentral.com/vehicle-help/1991-dodge-poweram150-stumble-off-idle/
    https://ramchargercentral.com/vehicle-help/hesitation-problems-88-318-rc/
    https://ramchargercentral.com/vehicle-help/89-dodge-w150-tbi-truck-almost-stalls-with-very-little-throttle/
    https://ramchargercentral.com/vehicle-help/318-tbi-random-stalling/
    https://ramchargercentral.com/vehicle-help/another-tbi-hesitation-thread/
    https://ramchargercentral.com/vehicle-help/89-dodge-power-ram-w360-tbi-hesitates-and-sputters-when-pushing-gas-pedal/
    https://ramchargercentral.com/vehicle-help/89-ramcharger-problems/
    https://ramchargercentral.com/vehicle-help/stumbles-hard-on-acceleration-86-rc-318-holley-2280-2bbl-auto-trans/
    https://ramchargercentral.com/vehicle-help/can-you-check-a-fuel-injector/
    https://ramchargercentral.com/vehicle-help/318-dies-worse-than-ever/
    https://ramchargercentral.com/vehicle-help/88'-rc-bogged-down-performance-stalling-fuel-issues/
    https://ramchargercentral.com/vehicle-help/light-throttle-stumble/
    https://ramchargercentral.com/vehicle-help/89-ramcharger-problems/
    https://ramchargercentral.com/vehicle-help/tbi-guru's-only-stumblebog-but-no-cause-found/
    https://ramchargercentral.com/vehicle-help/tbi-experts-help-with-90-ram/50/
    https://ramchargercentral.com/technical-discussion/intermittent-misfire-and-bog/
    https://ramchargercentral.com/vehicle-help/90-ramcharger-stumbles-just-off-idle-89-ramcharger-has-vacuum-problems/

    And in all of that the only pattern I found is that there is no pattern. Nearly every truck ended up having a different issue. I was hoping the specific symptoms would lead to some specific order of testing and I guess now I know connectors at the back is the starting point.
    ~Michael~

    89 Ramcharger 318
    87 Mercedes 300SDL
    96 Grand Marquis
    97 Acura CL
    04 Trailblazer
    10 BMW X5 35d

    Offline DODGEBOYS

    • DODGEBOYS.NET / RCC Signiture Police
    • RCC Addict
    • ********
    • Posts: 26576
    • Gender: Male
    • 45yr ASE Master Mechanic [Electronic Diagnostics]
      • DODGE TRUCKS @ DODGEBOYS.NET
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #3 on: December 20, 2019, 10:38:10 pm »
    after rereading your novel instead of skimming it , if its code 52 RICH then the PCM is makng it run LEAN and thats the cause of the stumble , l,d look at the injector spray pattern , you can see them best with a timing light pointed at them
    put your truck info HERE
    MOPAR TO YA!!!!!! AARON HOWORD TOWNSEND / SLANTEDMIND---GOD BLESSDODGEBOYS FSM STORE
    [email protected]
    former Parts Mgr & A1 Tech @ Pete's Chrysler -Plymouth
    DO NOT use the site IM,s to contact me  l have them turned OFF

    Offline DODGEBOYS

    • DODGEBOYS.NET / RCC Signiture Police
    • RCC Addict
    • ********
    • Posts: 26576
    • Gender: Male
    • 45yr ASE Master Mechanic [Electronic Diagnostics]
      • DODGE TRUCKS @ DODGEBOYS.NET
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #4 on: December 20, 2019, 10:46:43 pm »
    sorry about the first reply , my old eyes cant read more than a couple sentences before they go blurry and my attention deficit disorder is terminal 
    put your truck info HERE
    MOPAR TO YA!!!!!! AARON HOWORD TOWNSEND / SLANTEDMIND---GOD BLESSDODGEBOYS FSM STORE
    [email protected]
    former Parts Mgr & A1 Tech @ Pete's Chrysler -Plymouth
    DO NOT use the site IM,s to contact me  l have them turned OFF

    Offline DODGEBOYS

    • DODGEBOYS.NET / RCC Signiture Police
    • RCC Addict
    • ********
    • Posts: 26576
    • Gender: Male
    • 45yr ASE Master Mechanic [Electronic Diagnostics]
      • DODGE TRUCKS @ DODGEBOYS.NET
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #5 on: December 20, 2019, 10:51:08 pm »
    also you need a multimeter to check the TPS voltage at the tps and then the same test at the PCM , you can email me for the diagrams = include all info my emaiil is below
    put your truck info HERE
    MOPAR TO YA!!!!!! AARON HOWORD TOWNSEND / SLANTEDMIND---GOD BLESSDODGEBOYS FSM STORE
    [email protected]
    former Parts Mgr & A1 Tech @ Pete's Chrysler -Plymouth
    DO NOT use the site IM,s to contact me  l have them turned OFF

    Offline benzdiesel

    • Newbie
    • *
    • Posts: 21
    • Gender: Male
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #6 on: December 20, 2019, 10:54:30 pm »
    Does it need to be the kind of timing light that has an adjustment on it for delaying or advancing the measurement? Mine doesn't have that, so I can't be sure if the light was showing the fuel during the injection or during the gaps between sprays. I connected it to the #1 plug wire.

    Just went out and looked again (I had looked earlier but couldn't tell much).

    The injector on the driver's side seems to be spraying some pretty big fuel droplets. I can't tell anything at all about the shape of the pattern (which is why I'm wondering if I'm doing the test right or if maybe my light is not in sync with the injectors; is there something better than the #1 plug wire to connect the pickup lead to?) but it's a pretty heavy spray of fuel and there's some fuel dripping down the back wall of the housing behind the injector.

    I couldn't honestly see any fuel at all coming out of the one on the passenger's side. If that injector was completely dead, would it be able to idle as it does, or to achieve any significant RPM once you push the accelerator further down past the stumble zone?
    ~Michael~

    89 Ramcharger 318
    87 Mercedes 300SDL
    96 Grand Marquis
    97 Acura CL
    04 Trailblazer
    10 BMW X5 35d

    Offline DODGEBOYS

    • DODGEBOYS.NET / RCC Signiture Police
    • RCC Addict
    • ********
    • Posts: 26576
    • Gender: Male
    • 45yr ASE Master Mechanic [Electronic Diagnostics]
      • DODGE TRUCKS @ DODGEBOYS.NET
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #7 on: December 20, 2019, 11:03:55 pm »
    without the dial back timing light l,d try every plug wire including the coil wire to find the one that shows the pattern best , if one side is pouring and the other side is dead , l,d look at either the wring [ valve cover plugs] or the injector its self , also can you get your hands on some NOID lights to check the injector pulse on the dead one 
    put your truck info HERE
    MOPAR TO YA!!!!!! AARON HOWORD TOWNSEND / SLANTEDMIND---GOD BLESSDODGEBOYS FSM STORE
    [email protected]
    former Parts Mgr & A1 Tech @ Pete's Chrysler -Plymouth
    DO NOT use the site IM,s to contact me  l have them turned OFF

    Offline DODGEBOYS

    • DODGEBOYS.NET / RCC Signiture Police
    • RCC Addict
    • ********
    • Posts: 26576
    • Gender: Male
    • 45yr ASE Master Mechanic [Electronic Diagnostics]
      • DODGE TRUCKS @ DODGEBOYS.NET
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #8 on: December 20, 2019, 11:07:26 pm »
    the intake is not separate so it will run fine on one leaky injector but wll stumble hard if you try to drive it = sound farmiliar
    put your truck info HERE
    MOPAR TO YA!!!!!! AARON HOWORD TOWNSEND / SLANTEDMIND---GOD BLESSDODGEBOYS FSM STORE
    [email protected]
    former Parts Mgr & A1 Tech @ Pete's Chrysler -Plymouth
    DO NOT use the site IM,s to contact me  l have them turned OFF

    Offline benzdiesel

    • Newbie
    • *
    • Posts: 21
    • Gender: Male
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #9 on: December 20, 2019, 11:40:39 pm »
    ========
    TPS TESTS
    ========

    Voltage from purple to black (outside connectors) with key on, TPS unplugged, = 4.97-5.00 VDC.
    Voltage from orange (middle connector) to ground with sensor connected, engine running at idle = 0.972VDC. A little lower than the site here indicates is desirable (but within what he says the factory spec is): http://dodgeram.org/tech/transmission/automatic/TPS_adjust.htm

    Note I did not read from orange to black, I read from orange to various random grounded points on the block itself. I didn't figure it would matter, ground should be ground and I know the black pin of the connector is a good ground from the first test with it unplugged... but I can test again if this was not a valid test.


    When you say to test voltage at the PCM, where physically am I looking? I was expecting to see a big block of connectors somewhere near the firewall in the engine bay but outside in the dark after a long day I couldn't spot it. I have a FSM; wiring diagram D11 says it is "center of dash panel" which implies I'm going to be working inside the cab under the dash, rather than in the engine bay, for this test?

    ========
    INJECTORS
    ========


    With the timing light moved to various wires I confirmed that both injectors are in fact producing fuel. I don't think I have the necessary experience to recognize a good pattern from a bad one but they're both functioning to some extent. The drivers side one is still noticeably wetter than the passenger side; passenger side you can only see the fuel if you look close in the timing light; drivers side, you can see with just a regular flashlight there is liquid fuel dripping off the throttle butterfly and down the sides of the chamber.

    It only stumbles with the throttle at that just barely off idle position. If you go on and put your foot down it picks back up, further suggesting the injectors are at least functioning even if not optimal. It does not continue to stumble under heavy acceleration.

    I'll have to look into noid lights, I had never heard of them until tonight.

    Tomorrow's another day, I'll work on those valve cover connectors and, once I figure out where the PCM is, try to test that TPS voltage at the PCM.
    ~Michael~

    89 Ramcharger 318
    87 Mercedes 300SDL
    96 Grand Marquis
    97 Acura CL
    04 Trailblazer
    10 BMW X5 35d

    Offline crazzywolfie

    • Sr. Member
    • *****
    • Posts: 4764
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #10 on: December 21, 2019, 12:50:45 am »
    i believe you can test the voltage readings coming off the o2 sensor to see if it is function as it should. you could try unplugging the o2 sensor and see if it drives the same. yours sounds like it is doing the exact same things mine was doing before i replaced the o2 sensor. it would sit there idling all day but had to give it gas just right to go and keep it from stalling but once you get going it was fine till it would shift and fall on its face again.
    93 RamCharger 2wd 318
    89 RamCharger 4x4 318/727/3.21 on 33's
    81 d150 long box 318 670CFM Holley Carb
    If you can't fix it with a hammer, you've got an electrical problem

    Offline dodge82273

    • RCC Nut
    • *******
    • Posts: 11738
    • Gender: Male
    • RCC Rules!
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #11 on: December 21, 2019, 01:52:04 am »
    you say that the last time you checked the fuel pressure was good . Did it also run good ( no stumble) at THAT time?  droplets seen rather than spray? low fuel pressure can cause that . Rich smell ? liquid gasoline does not burn , only spray or vapors burn , droplets will cause unburnt rich smell at tailpipe and o2 sensor as the raw fuel vaporizes in the exhaust , but a lean effect on the combustion chamber ( because droplets don't ignite) ( stumble ) .
     next thing to do : check the fuel pressure now , and as the problem is occurring . Fuel pressure does NOT itself have a code to set . 
    78 to 93 parts trucks
    91 w250 318 518 44/60 single 9 foot driveway plow locked
    87w150 44/corp727 kandy w/ ghost bats/summer
    86-D/W100 44/corp/318mag/carb/4500/aka shit box/winter
    93w150short/44/corp/360/le/mag "caddie"
    93w250LB51844/60posi 318"New Truck"
    93w350 6 tire CC 60 c/a flat bed dump

    Offline Ajaxzem

    • Newbie
    • *
    • Posts: 65
    • Gender: Male
    • RCC Rules!
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #12 on: December 21, 2019, 08:20:41 am »
    you might want to check out the thread I posted a while back. I had the same type of symptoms. If I went anywhere off idle it would try and die on me, but it was fine at wide open throttle. I replaced EVERY sensor on the truck, fuel pump, distributor, throttle body, injectors...etc. I had on o2 sensor code but ignored it because I didn't think an o2 sensor could make it run THAT bad.
         after I changed it my truck ran like new. I think it had an internal short and it was throwing everything else out of wack.
    89 W100, 5.2 3SPD SHORTBED.

    Offline zx1100ninja

    • Newbie
    • *
    • Posts: 32
    • Gender: Male
    • RCC Rules!
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #13 on: December 22, 2019, 01:20:08 pm »
         I have 88 Ramcharger 318 TBI
         I had same drive ability issues

         1.  I had a faulty fuel pressure regulator.  Ran well for a month.
         2.  I then had a faulty EGR valve.  Plugged line and ran perfectly. 
         
    John
    79 Power Wagon
    88 Ramcharger
    91 Ram 250

    Offline benzdiesel

    • Newbie
    • *
    • Posts: 21
    • Gender: Male
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #14 on: February 9, 2020, 06:12:24 pm »
    Today was the first day I've had any time to work on the truck since my last posts. I tried to take as many suggestions as I could.

    * I installed 2 brand new fuel injectors, no improvement.
    * I disconnected 3 plugs at the rear of the passenger valve cover, marked with 3 colored dots (red, blue, and green) and sprayed electronics cleaner into both halves of each connection. I did the same for 3 loose dangling wiring harness connectors I found in the same vicinity up by the firewall. I'm not sure what they all were (one of them had the starter relay circuit in it, because the truck wouldn't crank at all with it disconnected, and one of them looks like it might be the o2 sensor based on pictures of o2 sensors I've looked at online) but they're all clean now and didn't help.
    * Checked fuel pressure. The pressure hovers somewhere between 14 and 15 psi (the scale is hard to read on my gauge and the connections were leaky which made the reading a little lower than actual) at all speeds and throttle positions including while the engine is stumbling and choking. It does not hold prime once the engine shuts down, it bleeds to 0 almost instantly. But it holds a steady 14-15 the whole time it's running. 
    * Tried running it with the MAP sensor unplugged and it ran worse; stumbled at all speeds instead of only this one position.
    * Tried running it with the TPS unplugged and it died immediately.
    * The smog pump (not sure what the actual name is, but it's the pulley driven emissions device on the uppermost, drivers side position of the front pulley array) already has its vacuum line unplugged and capped off. When you connect this device it makes a roaring noise which is probably why someone disconnected it. (I sold the truck last year then bought it back and this was done while the other guy had it. It didn't roar when I sold the truck originally.)
    * I tried holding the throttle in the position that causes the stumble and then giving it a light squirt of starting fluid down the throttle body, with the thought that if it's leaning out, then some extra easy-burning fuel would make it come back to life. Instead it seemed to choke down until the spray was gone. 
    * Brand new throttle position sensor, made no difference.

    The truck has a huge exhaust leak near the headers at the moment, to the extent that I am not sure I would trust an O2 sensor to give valid readings whether it's working correctly or not due to external atmosphere being present and exhaust leaking out rather than going down the pipe. I'm not ignoring the 2 posts saying similar issues were resolved this way, but I'm also not sold on how it could be causing such a specific problem where it runs fine except for one throttle position.

    Is the O2 sensor connection a connector up near the firewall on the passenger side near the ignition coil, square shaped connector with 4 pins in the truck end and 3 pins in the sensor end, with a yellow seal on the inside? If so then I can confirm unplugging it makes no difference, the truck runs the same with or without that connector connected. I guess I've already thrown enough parts at the thing one more won't hurt but I really feel like this is throttle related somehow.

    The problem seems very closely linked to the actual physical position of the throttle linkage. I am wondering if there is something wrong inside the throttle body... something loose, or broken, or worn, or a bad spring somewhere, etc... causing just that one throttle position not to have the effect it should. I wouldn't know what I was looking for even if I tried to take it apart.

    It's not easy to see in the video exactly how I'm moving the throttle, but take my word for it -- at idle, it's great; with 1/3 or more throttle, it's great, but there is a very small range of movement just above idle where the thing will not run correctly for as long as you hold the throttle in that position. Go below or above that dead spot and it runs as well as can be expected. Does this give anyone any clues that the description alone did not? https://www.youtube.com/watch?v=p7zoiAsNruM

    If O2 is still the best guess I can see about changing it. I'm also thinking about trying a junkyard throttle body from a pull-a-part type place if I can find one for not too much money. Short of that I'm running low on ideas.
    ~Michael~

    89 Ramcharger 318
    87 Mercedes 300SDL
    96 Grand Marquis
    97 Acura CL
    04 Trailblazer
    10 BMW X5 35d

    Offline ToxicDoc

    • Lifetime Supporter
    • RCC Nut
    • *
    • Posts: 13660
    • Gender: Male
    • RCC Rules!
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #15 on: February 9, 2020, 07:36:45 pm »
    Ninja made mention of it, check the EGR valve
    '85 W150 SB, 408 stroker, Magnum manifolds, Performer RPM, 670 Truck Avenger, HEI ignition, Auburn LSD 9.25 and '82 D44 (non-CAD) with 3.55/3.54,  NV4500/NP241

    Offline modelcitizen

    • RCC Rookie
    • **
    • Posts: 404
    • RCC Rules!
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #16 on: February 9, 2020, 08:53:55 pm »
    Op mentions fuel system bleeds pressure off immediately on shutdown. This needs to be investigated. Fuel system needs to maintain pressure to keep system prime. Op should pinch off return hose while truck is running and observe fuel pressure gauge reading. Either pressure regulator is stuck open and shunting all fuel to tank,fuel pump or pressure hose connecting pump in tank has an issue or check valve in pump is faulty.

    Offline DODGEBOYS

    • DODGEBOYS.NET / RCC Signiture Police
    • RCC Addict
    • ********
    • Posts: 26576
    • Gender: Male
    • 45yr ASE Master Mechanic [Electronic Diagnostics]
      • DODGE TRUCKS @ DODGEBOYS.NET
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #17 on: February 9, 2020, 09:09:55 pm »
    Date: October 30, 1989

    Models: 1988-89 D/AD Ram Pickup, Ramcharger

    Also Body Code:
    B/AB - DODGE RAM VAN/WAGON (RWD)
    D/AD - DODGE RAM PICKUP/RAMCHARGER SPORT UTILITY (RWD, 4WD)
    N/AN - DODGE DAYOTA/DAKOTA SPORT (RWD, 4WD)

    Symptom/Condition:

    No start, surge or hesitation due to insufficient fuel supply to the throttle body. This condition may be caused by a ruptured fuel supply hose at the in-tank fuel pump module.

    Diagnosis:

    Before performing the diagnosis for the above SYMPTOM/ CONDITION, perform the Fuel System Pressure Release Procedure as called out in the "Fuel System" section of the appropriate 1988 or 1989 service manual.

    The following procedure will help in diagnosing a ruptured fuel pump supply hose.

    1. Disconnect the fuel supply hose from the throttle body.

    2. Connect fuel system pressure tester, Miller Tool C-4799-A, to the fuel supply hose.

    3. Connect DRB 11 diagnostic tester to the vehicle connector. Turn the ignition key to the "Run" position. Cycle the DRB II to the Actuate Outputs Test for "Auto Shutdown Relay." This will activate the fuel pump and pressurize the system.

    4. The pressure gauge should stabilize at 100 Kpa 7 Kpa (14.5 psi 1 psi).

    5. Clamp the fuel return hose shut at the throttle body. The fuel pressure will increase and stabilize at approximately 345 Kpa (50 psi).

    6. Turn the ignition to the "OFF" position.

    7. If the fuel pressure drops slightly (less than 5 psi) and then stabilizes, the system is operating correctly.

    8. If the fuel pressure drops rapidly (to below 10 psi in one minute or less) a leak is present in the fuel supply system.

    9. if no leaks are visible between the fuel tank and the throttle body, the problem is most likely a ruptured fuel supply hose at the fuel pump module.

    10. Remove the fuel return hose clamp and the fuel pressure tester.

    Parts Required:

    1 Fuel Supply Hose (B/AB)                PN 52006220
    1 Fuel Supply Hose (D/AD, N/AN)    PN 52006219

    Service Procedure:

    This procedure outlines the replacement of the fuel supply hose at the fuel pump module.

    1. Remove fuel tank assembly from vehicle.

    2. Remove fuel pump module from fuel tank.

    3. Using service manual procedures (Page 14-4 of 19B9 Rear-wheel-Drive Truck Manual #81-370-9008), disassemble fuel pump module assembly just to the point of being able to remove the fuel supply hose from the fuel pump module lid (Figure 1).

    4. Remove fuel supply hose from fuel pump.

    5. Remove pump mounting bracket and rubber collar from hose. Discard hose and clamps.

    6. Slide clamps included in package onto new supply hose (see "PARTS REQUIRED" for application). Install supply hose with the short end attached to module lid. Attach fuel pump to supply hose. Tighten clamps to 1 N-m (10 in. lbs.).

    7. Install pump mounting bracket and rubber collar on hose, positioning bracket just under locating clamp on hose.

    8. Reassemble module.

    9. Install module into fuel tank and install fuel tank in vehicle.

    10. Start vehicle to check for fuel leaks and to verify proper operation.

    Notes:

    POLICY:     Reimbursable within the provisions of the warranty.

    TIME ALLOWANCE:
    Labor Operation No.       14-50-01-94 (B) . . . . . . . . . . . . . . . .  1.4 Hrs.
                                                                (A, D), X, W, N) . . . . . . 1.3 Hrs.

    FAILURE CODE: X2 - Split, Cut or Torn

     
    « Last Edit: February 9, 2020, 09:15:12 pm by DODGEBOYS »
    put your truck info HERE
    MOPAR TO YA!!!!!! AARON HOWORD TOWNSEND / SLANTEDMIND---GOD BLESSDODGEBOYS FSM STORE
    [email protected]
    former Parts Mgr & A1 Tech @ Pete's Chrysler -Plymouth
    DO NOT use the site IM,s to contact me  l have them turned OFF

    Offline benzdiesel

    • Newbie
    • *
    • Posts: 21
    • Gender: Male
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #18 on: February 12, 2020, 05:28:17 pm »
    Well I'll be darned. Once I finally figured out what the EGR looked like and located it, I disconnected the vacuum line between the solenoid and the actual valve and plugged it with a custom brass leakproof .22 caliber vacuum line stopper I found conveniently laying in the driveway... and standing there doing the thumb-on-the-throttle test it no longer stumbles. I'm going to go on an actual test drive once I get the air cleaner and such reinstalled before I proclaim it "fixed" but it looks promising.

    Some other forum threads have said leaving it just like that in perpetuity will not cause any long term harm, though it might let a little extra gunk form up in the intake... others have said do it right and make/install a block off plate. Is there a common consensus on this? Same question on the pulley driven smog/air pump; is leaving it installed but the vacuum line capped off going to damage the truck long term in any practical sense?

    Thanks, everyone. I'll post back once I've test driven with more thorough results and update the post title, etc.
    ~Michael~

    89 Ramcharger 318
    87 Mercedes 300SDL
    96 Grand Marquis
    97 Acura CL
    04 Trailblazer
    10 BMW X5 35d

    Offline ToxicDoc

    • Lifetime Supporter
    • RCC Nut
    • *
    • Posts: 13660
    • Gender: Male
    • RCC Rules!
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #19 on: February 12, 2020, 06:08:30 pm »
    Better to put a plate on it or replace the valve. I'd be concerned it's failed partially open and can affect fuel mix
    '85 W150 SB, 408 stroker, Magnum manifolds, Performer RPM, 670 Truck Avenger, HEI ignition, Auburn LSD 9.25 and '82 D44 (non-CAD) with 3.55/3.54,  NV4500/NP241

    Offline Chilly

    • RCC Rookie
    • **
    • Posts: 364
    • RCC Rules!
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #20 on: February 15, 2020, 09:29:06 am »
    If you think the truck will ever be subject to under-hood emissions inspection I'd clean it up to make sure it is seated closed.  Then pack the vacuum line to it with RTV.  Let it cure (needs exposure to air) and reattach.

    I think the actuator diaphragm must be rusted or leaking, causing vacuum dump
    92 Ramcharger
    360 TBI, auto, 241 t-case
    44F, 9.25R posi, 3.54 gears (yeah, I know)
    Skyjacker 4", 33x12.5

    Offline benzdiesel

    • Newbie
    • *
    • Posts: 21
    • Gender: Male
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #21 on: May 15, 2020, 10:40:37 am »
    Just to close the loop on this one before it gets any older, replacing the EGR valve with a new part (decided not to fool with blocking off or other trickery) has eliminated the issue. Thanks once again for all your help. Sorry to reopen an old discussion but figured for future readers it would be good to post the final confirmation.
    ~Michael~

    89 Ramcharger 318
    87 Mercedes 300SDL
    96 Grand Marquis
    97 Acura CL
    04 Trailblazer
    10 BMW X5 35d

    Offline ToxicDoc

    • Lifetime Supporter
    • RCC Nut
    • *
    • Posts: 13660
    • Gender: Male
    • RCC Rules!
    Re: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #22 on: May 15, 2020, 03:07:58 pm »
    Just to close the loop on this one before it gets any older, replacing the EGR valve with a new part (decided not to fool with blocking off or other trickery) has eliminated the issue. Thanks once again for all your help. Sorry to reopen an old discussion but figured for future readers it would be good to post the final confirmation.

    We like the follow up. it definitely helps. No need to apologize. We're glad you have resolution of the problem.
    '85 W150 SB, 408 stroker, Magnum manifolds, Performer RPM, 670 Truck Avenger, HEI ignition, Auburn LSD 9.25 and '82 D44 (non-CAD) with 3.55/3.54,  NV4500/NP241

    Offline Chilly

    • RCC Rookie
    • **
    • Posts: 364
    • RCC Rules!
    Re: FIXED: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #23 on: May 16, 2020, 07:13:16 am »
    Thinking about this: which is the most likely root cause?

    1. EGR diaphragm was leaking, causing an open vacuum leak through the diaphragm, or

    2. EGR was stuck open, introducing exhaust gasses into the intake manifold below the throttle body.

    92 Ramcharger
    360 TBI, auto, 241 t-case
    44F, 9.25R posi, 3.54 gears (yeah, I know)
    Skyjacker 4", 33x12.5

    Offline benzdiesel

    • Newbie
    • *
    • Posts: 21
    • Gender: Male
    Re: FIXED: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #24 on: May 21, 2020, 08:38:03 pm »
    For what it's worth, the symptoms went away when I unhooked the vacuum supply to the EGR device and plugged it with an empty .22 casing prior to physically removing the EGR from the truck. As soon as I plugged that vacuum line, truck ran great.

    That makes me think that of your two possibilities, #1 is more likely what the truck was responding to. If it were #2, then removing or adding the vacuum shouldn't make any difference, should it, given that the device itself couldn't respond to any vacuum that was or was not supplied?

    They aren't mutually exclusive failures, that being said. #2 could have happened years ago and not affected how the truck ran for whatever reason until #1 happened which is what caused the trouble.

    Just guessing.
    ~Michael~

    89 Ramcharger 318
    87 Mercedes 300SDL
    96 Grand Marquis
    97 Acura CL
    04 Trailblazer
    10 BMW X5 35d

    Offline dodge82273

    • RCC Nut
    • *******
    • Posts: 11738
    • Gender: Male
    • RCC Rules!
    Re: FIXED: 89 TBI 318 idles fine, nearly dies with slight throttle
    « Reply #25 on: May 22, 2020, 02:28:26 am »
    egr being triggered is what turns the vac on in that line TO it , otherwize its a dead line , only has vac when egr is suppose to be open/on so , the control for egr is at fault allowing egr open at wrong time , or vac leak at faulty diaphragm egr to occur ....if 2 things were bad ...
    78 to 93 parts trucks
    91 w250 318 518 44/60 single 9 foot driveway plow locked
    87w150 44/corp727 kandy w/ ghost bats/summer
    86-D/W100 44/corp/318mag/carb/4500/aka shit box/winter
    93w150short/44/corp/360/le/mag "caddie"
    93w250LB51844/60posi 318"New Truck"
    93w350 6 tire CC 60 c/a flat bed dump