Need a little diagnostic help... (1 Viewer)

[wob]

The last three times I have driven my truck now, once it warms up after a few minutes, it cuts off. It will not restart until a few hours later once it cools off, it seems. After it cuts off, the car turns over fine, it just won't fire up.

Any ideas where to begin?

'96 LC, 133K on the ticker

 

[jfz80]

sorry.......off topic but SC is socal still? or have you swapped coasts? hit us up in the Upstate section if you made it this way.

 

[wob]

sorry.......off topic but SC is socal still? or have you swapped coasts? hit us up in the Upstate section if you made it this way.

I've been in South Cackalacky all along.

 

[CJF]

When failing to (re)start, is the CEL illuminated with the key in the ON position?

Curtis

 

[wob]

When failing to (re)start, is the CEL illuminated with the key in the ON position?

Curtis

I don't recall for sure, but I do not believe it did. The light does work, though.

I just let it idle for about fifteen minutes, then drove it around town close to home for about ten or so, with no cut off. It seems like it only cuts off when it is more than 90 degrees outside. EFI engines can't get vapor lock, can they?

 

[powderpig]

So do you have fuel pressure? Do you have spark? Do you have a FSM?
Typically the 1FZ does not get vapor lock. Have you done any diagnostics?

 

[wob]

So do you have fuel pressure? Do you have spark? Do you have a FSM?
Typically the 1FZ does not get vapor lock. Have you done any diagnostics?

I dunno
I dunno
yes
diagnostics? That's what the vast knowledge is here for, correct?


Just wondering if anyone has experienced what I have, or where I should start. Many times something as simple as a symptom or two will spark some debate and suggestions from folks on here.

I'm thinking it's a fuel issue, though. A few days ago, I was going up a relatively steep incline, and it acted like it was about to cut out. I think I'm gonna do the old reliable wob fix and suck some SeaFoam into the intake via the pcv valve. That has made it run better in the past.

 

[concretejungle]

electrical?

 

[wob]

electrical?

I dunno - that's what I was thinking at first, but the battery has plenty of power, and everything else works. I was one of the first to go down the road of bad wires around the back of the engine, and that only would cut out when in a forward gear with the engine torquing. I do not think it's that again.

 

[Ebag333]

I don't recall for sure

I dunno
I dunno
diagnostics? That's what the vast knowledge is here for, correct?

I dunno

Sounds like you might want to take it into a reputable mechanic who can answer these questions.

Yes sometimes a few symptoms can spark of suggestions, but unless you can actually give feedback on if those suggestions are valid/invalid, then not much can be done on here.

Either that or break out the FSM and start testing the already suggested componants.

 

[powderpig]

You have the best amount of info in the fsm. follow the trouble shooting guide in the manual and it will lead you to the problem. And the answer.
You want info and it is real apparent that you have not done any of the basic diagnostic's that could help every one. Good luck

 

[Beowulf]

I dunno
I dunno
yes
diagnostics? That's what the vast knowledge is here for, correct?

-B-

 

[re_guderian]

https://forum.ih8mud.com/80-series-tech/235600-95-tlc-wont-restart.html

No answers, but you're not alone...

 

[wob]

No, I have not checked anything yet. I posted up what the problem was, thinking someone might know where to look or had heard of something similar happening. Like the wiring harness getting chafed, whenever someone begins to describe what is happening, several of us know exactly what the problem is. That is what I was hoping for. It's not like I came on here and posted "My truck will not start. Tell me what is wrong. No, I have not checked the battery."

And Ebag333, look at the times posted on the thread when I first got some suggestions where to start looking - 9:30 last night. I was not going to mess with it then. Thanks for your help and concern.

 

[wob]

https://forum.ih8mud.com/80-series-tech/235600-95-tlc-wont-restart.html

No answers, but you're not alone...

Thanks, re. That's about what I was looking for.

 

[knorrena]

I had this happen to me and the problem turned out to be electrical. The key factor in helping me figure this out is what one other person has already asked you: is your cel lit when you are trying to start the truck? Mine was not.

I checked all my fuses and all was good. Then I checked power to the first fuse before the ecu (the fuse box under the hood) and I had none. I stripped the wiring harness and found a mildly corroded splice (it was a factory splice too). The splice was the first splice in the white wire that powers the ecu (check your ewd for specific mappings).

I concluded that the ecu is somewhat sensitive to voltage and that the corrosion dropped the voltage to the point where the ecu would not work. I have not had any problems at all since I fixed the splice.

Karl

 

[wob]

I had this happen to me and the problem turned out to be electrical. The key factor in helping me figure this out is what one other person has already asked you: is your cel lit when you are trying to start the truck? Mine was not.

I checked all my fuses and all was good. Then I checked power to the first fuse before the ecu (the fuse box under the hood) and I had none. I stripped the wiring harness and found a mildly corroded splice (it was a factory splice too). The splice was the first splice in the white wire that powers the ecu (check your ewd for specific mappings).

I concluded that the ecu is somewhat sensitive to voltage and that the corrosion dropped the voltage to the point where the ecu would not work. I have not had any problems at all since I fixed the splice.

Karl

That is a good place for me to start. When I had the original harness chafing issue mentioned above, the mechanic thought that the wire coming from the battery might be the problem. He went in, and replaced some wires there, but obviously that did not fix my problem. There is a good chance that that "fix" might have started corroding by now. I'll check that first.

 

[concretejungle]

i was going to suggest wiggling the wiring harness once you get the truck running to see if it sputters or cuts off. Maybe wiggle all the wires you can get your hands on while it's running to see if anything happens.

 

[knorrena]

Have you read the FAQ's? Have you searched?

We can't help you unless you give us something.

Are you from France? You are unbelievably rude, Frenchie.

WTF kinda post is that? First you insult someone but I cant tell who, then you repeat something that some else has already mentioned. Nice work.

 

[wob]

WTF kinda post is that? First you insult someone but I cant tell who, then you repeat something that some else has already mentioned. Nice work.

He was digging at me - don't sweat it.

The battery is new, and the connection there seems pretty tight. I'll dig into the wires coming off of the battery when I get a chance - which will probably be a day or two from now.