Truck won't REstart.

[SoCalJohn]

Well, just a small annoying issue with the truck. For a month or so, after a 5 minute drive to a long drive, as soon as I turn off the ignition, the truck will not immediately restart. It requires a 3-5 minute wait before it will restart. Starter is strong and cranks, but sounds "dry" . I do not smell any fuel from flooding during this process, but I don't think that occurs with EFI. Here are the several steps my mechanic and I have taken after searching several treads here.
1. Spark Plugs, good
2. Plug Wires in good shape
3. Distributor Cap and lower portion in good shape, also conducted voltage test, within allowable range. Voltage also tested on coil, passed test.
4.I replaced ingnitor and coil with spares on hand, still have same issue.
5.Fuel Pump in good shape as well as battery.
6. Replaced EFI fuse. In engine bay. Big Round One Top/Left

Not examined yet are ECU, and some searches mentioned wiring harness as a possible suspect. Another 91 FJ80 was in the shop at the same time, and they are trying to source the wiring harness, cheap. Can there be other components of the ignition or fuel system that could be suspect?

Just waiting for it to get worst, not so bad around town, but don't want same issues out in desert. Any Comments... Am I on the right track? Or way off...Much Thanks

 

[CJF]

Replaced EFI fuse. In engine bay. Big Round One Top/Left

That's the EFI relay, which is indeed the main cause of no start on a 3FE. Even better than replacing it would be to carry a spare and see if swapping it out when the problem occurs makes a difference. Look here for more about EFI diagnostics (from our member Jon Held):

http://gclcny.com/jh/images/Strife/EFIdiag.pdf


Number two suspect in my mind would be the Fuel Pressure Regulator (FPR). Look here for more on that:

https://forum.ih8mud.com/60-series-wagons/6464-3fe-fuel-supply-problem-i-fixed.html


Wiring harness is generally not an issue on 91-92's.

Curtis

 

[jonheld]

Number two suspect in my mind would be the Fuel Pressure Regulator (FPR).

I also like the FPR given the symptoms [no fire when hot] or possibly the check valve on the fuel pump if the FPR has been in a failed state for a while.

Does this truck run normally in all conditions once it is started?
Does it ever stall?

 

[SoCalJohn]

Thank You Gentleman. Truck runs strong and does not stall. I also did the EFI switch trick for a few day. I will reveiw these threads and report back.

John

 

[jonheld]

Truck runs strong and does not stall.

Then we're looking at "no fire when hot" as the only issue here, correct? If it runs well once it is started in all conditions then the fuel pump is working well. Again, looks like typical FPR symptoms.

Next time you get into a no start situation, simply check for spark at a plug. If spark and no fire = no fuel.

 

[SoCalJohn]

I will check for spark. Thanks Jonheld and CJF for the help and speeding up my repair process. I will order this part. John

 

[SoCalJohn]

CJF and jonheld, I put the new FPR in today, and all back to normal, Truck restarts every time, and no more long cranking to start the engine either. One bolt was tricky to get to, had to remove various brackets and hoses that were in the way, then it went very fast.

Thanks again for the helpful advice, and the good price and fast shiping of Cdan.

John

 

[CJF]

Woohoo!

 

[SoCalJohn]

Well, spoke to soon, ran several errands last night and this morning with no problems restarting, but now it is back. So with a brand new FPR, maybe another fuel issue. Should I focus back on the fuel pump or is this an ignition system issue. Still will restart after waiting 5 minutes.

Never, did check spark, what is the proper safe way to do this?

 

[jonheld]

In a no start situation, with the key in the ON position, is the CHECK ENGINE light on? If it's on we can all but rule out the EFI circuit.

If the CE light is on, check for spark by pulling one wire off a plug and with the wire wrapped with a towel (so you don't get zapped) you can bring the plug end over to a ground point (screw, whatever). During cranking you should see a nice blue spark jump to the ground point. Or simply grab a plug wire with your bare hand while cranking. It doesn't hurt too much. Ask me how I know.

 

[IdahoDoug]

Snicker. Waiting for the little zap is the hardest thing to do. It doesn't hurt, but there's some deep in the brainstem fear of electricity that combines with the thought you our doing it to yourself that gives this comic proportions, eh?

DougM

 

[SoCalJohn]

Ah, yes.... I thought I would try it with a damp towel!! I will report back.

 

[SoCalJohn]

Ok,, I could not see a blue spark jump but I think I could hear the spark clicking several times against the ground, while my wife was cranking. Of course I am not in a no start position now, just sitting in my driveway. Do I need to replicate the problem beofe this test. So what does this mean.... I did not get any shock, how dissipointing, it was scary telling my wife to turn the key............... I don't like power, fell off a ladder working on lights once, and did not remember falling!!

 

[jonheld]

Next no-start please check for the CE light first. If it's on then feel free to zap all you want.

 

[IdahoDoug]

Just leave the spark plug wire cover off, so you can do this next time it will not start. Of course, you'll need someone to be stranded with you to turn the key......

DougM

 

[bthelton]

So could the coil be getting to hot? I have seen coils on Chevy's not produce fire when they get to hot and work when they cool off. But thats my .02

 

[SoCalJohn]

Well, my wife will be waiting in the drive way so I can do the spark test immediately after I turn the engine off and attempt to replicate my restart issue.

I was thinking again about the coil and ignitor. I switched them out with used ones, so maybe put the same problem right back in. And I don't have the restart issue for example if I drive down the block, or move my car to the street, so could it be heat related and the coil is failing?

By the way can a new FPR increase your gas mileage, my needle is moving down more slowly...

 

[SoCalJohn]

Pulled up to home, and was able to check the spark properly, under a no start situation. I could not see nor hear a spark with the random plug wire I placed against a ground bolt.

So what does that indicate, a bad coil or ignitor? Thanks for everyone help and time assessing this.

I want to solve myself, as my garage is losing interest, understandble as they are payed for billable hours, and they have not charged to date for the inspections.

 

[bthelton]

Well, my wife will be waiting in the drive way so I can do the spark test immediately after I turn the engine off and attempt to replicate my restart issue.

I was thinking again about the coil and ignitor. I switched them out with used ones, so maybe put the same problem right back in. And I don't have the restart issue for example if I drive down the block, or move my car to the street, so could it be heat related and the coil is failing?

By the way can a new FPR increase your gas mileage, my needle is moving down more slowly...

Could you have found a new mod for less than a $100 for the purpose of gas milage? Did u gain any power Just had to ask, you never know

 

[jonheld]

Pulled up to home, and was able to check the spark properly, under a no start situation. I could not see nor hear a spark with the random plug wire I placed against a ground bolt.

Next no-start please check for the CE light first.
Next no-start please check for the CE light first.
Next no-start please check for the CE light first.
Next no-start please check for the CE light first.
Next no-start please check for the CE light first.
Next no-start please check for the CE light first.

If you're not gonna pay attention to the responses, I can't help you.