1995 fzj80 will try and start but will only stay running if foot on gas

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Hey guys , I have a 95 fzj and I will only crank if im hitting the gas and as soon as I let off the gas it stalls out . Anyone had this issue or have a fix. I’m a wholesale auto dealer and understand terminology but not skilled in the mechanic area. (Working on that part slowly ) so if anyone has any tips , ideas or fixes please feel free to post them. Thanks in advance guys . This community has been super helpful to getting my rig back to good condition .
 
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In addition to checking for major vacuum leaks as Reiver stated above, I would also check for excessive slack in the accelerator cable, especially where it connects to the throttle body. You have three cables there, the Cruise Control, the Transmission Kickdown cable and the Accelerator Cable. If the cable has stretched or the adjusting nut/lock nut has loosened, you may not have the proper adjustment to keep the throttle body open to keep the engine running without your foot remaining on the gas pedal. On a 96 LC the proper idle after the engine is started and warmed up should be around 650 rpm’s.
 

ppc

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If the cable has stretched or the adjusting nut/lock nut has loosened, you may not have the proper adjustment to keep the throttle body open to keep the engine running without your foot remaining on the gas pedal.

@y2offroad ...
The IAC - Idle Air Control valve controls an air bypass around throttle butterfly. The butterfly stays closed so the cable adjustment has nothing to do with the proper functioning/adjustment. The air bypass needs to be clear and the IAC needs to be functioning properly
 
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Will the engine run OK initially on a cold start, then die once it starts to warm up?
 
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@y2offroad ...
The IAC - Idle Air Control valve controls an air bypass around throttle butterfly. The butterfly stays closed so the cable adjustment has nothing to do with the proper functioning/adjustment. The air bypass needs to be clear and the IAC needs to be functioning properly
This is my understanding as well. Tightening the cable might get you to idle but will not actually solve the underlying issue (whatever that is). Vacuum leaks, MAF, and IAC are first thoughts - enough to get started.
 

flintknapper

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It would be well to check for codes also. Basics first, (thorough inspection and cleaning of throttle body, vacuum leaks, check MAF connection for corrosion and see that it is well seated, check IAC). Test TPS.

Too....a little more info would be helpful. Is the vehicle not staying running at idle...or does any lift off the accelerator below a certain rpm result in the engine dying?
 
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It would be well to check for codes also. Basics first, (thorough inspection and cleaning of throttle body, vacuum leaks, check MAF connection for corrosion and see that it is well seated, check IAC). Test TPS.

Too....a little more info would be helpful. Is the vehicle not staying running at idle...or does any lift off the accelerator below a certain rpm result in the engine dying?
It will not start unless my foot is on the pedal and when I let off it stalls out . Getting a little more smoke from exhaust than usual as well .
 

Bambusiero

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Yeah - 2nd checking the air intake tube for leaks - I just completed a 1" body lift install, started right up afterward - but would not stay running or idle - and backfires. turned out that all that tilting and lifting of the body pulled the air intake tube off.
 
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I would be looking for an air leak on the intake too. It starts with your foot on the gas because it’s helping balance the air to fuel ratio. Once you let off the gas, way too much air for the amount of fuel and it dies.
 
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I have '95, just replaced the IAC valve, was causing fluctuating RPMs, then stuck 2000 RPM, regardless of gas pedal position...and btw, TPS sensor was fine. That's the good news. Bad news was after IAC valve was replaced, it would stall unless gas pedal was depressed. Mechanic then did some additional diagnostic, he was expecting the CEL to come on, but it didn't. His conclusion was that the ECU was bad, I'll ask more about it, didn't have time to ask, was at work.

Tough pill to swallow, but the mechanic comes highly recommended from another cruiser owner, he's is a former master mechanic for Toyota with his own shop now. BTW, have done all the checks suggested in forums too with no success.

I'll let you know how it goes...just need to find an ECU now without paying an arm and a leg. DM me if you'd like. Forgot to mention, no codes have ever come up.
 
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What's the part number of your ECU? It's located behind the glove box but I'm not sure if it's visible without removing the box (too dark to go outside to look). There was an early ECU (pre 5/93??) that had the problems, 89661-60170. But if you have a 95 model you shouldn't have that early ECU.

Not the expert, wait for those to chime in, but seems like there's been very few bad ECU's other than that known early one.
 
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Joined
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What's the part number of your ECU? It's located behind the glove box but I'm not sure if it's visible without removing the box (too dark to go outside to look). There was an early ECU (pre 5/93??) that had the problems, 89661-60170. But if you have a 95 model you shouldn't have that early ECU.

Not the expert, wait for those to chime in, but seems like there's been very few bad ECU's other than that known early one.

I'll check tomorrow, looking forward to other thoughts and opinions. Thanks!
 

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