I drive a 2000 4.0 ohv 4X4 currently whenever the engine is warm it will not start:

When cooled down it will start just fine, but after a trip of any sort it will not start. If I turn the vehicle off and then try and turn it over immediately, it will start. After only 15 minutes of sitting it does not want to start again, then won't start until cooled down. Sometimes it will sputter but still will not start.

Starter cranks very strong.

Things I have replaced: Crank positioning sensor, cam positioning sensor, fuel pump (not the whole sending unit), fuel relay, idle air control valve, coil pack, plugs and wires, battery recently, alternator, and I used fuel system cleaner and heet.

I'm starting to believe this vehicle is a lemon, and am horribly frustrated. Utilizing haynes and alldata yielded no strong results.

Has anyone run into this problem? Does anyone have any other idea where to look for a cause?

I've heard of fuel vaporization in the fuel rails as a problem with these vehicles, along with the lines in the tank becoming weak due to ethanol in fuels...

 

I drive a 95 ford ranger 4.0l. mine will do the same thing. but mine will still crank when its hot but it will sit there and sound like its cammin out. it just dont idle right. my buddy up at the shop where i work thinks it my egr valve cause it will throw the egr code. (Exhaust Gas Recirculation) it gets carbon built up on it and it will make it not wanna run. hope that was any help..

 

I would assume egr issue but it seems to be non-existent on my truck. I only have the vapor canister purge valve, no egr.

I tried disconnecting the ecu to clear it with no luck and think it may be a result of a problem with the PATS system. Is this possible?

 

No.
PATS system won't even allow the truck to crank.

Have you cleaned your IAC? Those can act up when the truck is warm. Its located on top of the throttle body, two bolts (7mm iirc) and just clean it with Carb and Choke cleaner.

 

You need a Rotunda 007-00075 DIS distributorless Ignition system tester to find the interment fault.

Kent Moore Miller Rotunda Tools

If you get one I can get you the ford diagnostic steps.


I have a 95 ex with the same sickness, it refused to start on the hot days this week. I can tell you IAC is not the issue. I was hoping the cam sensor would help, but I see it is but a pipe dream.

 

stxdanger ranger: thank you very much, I was worried that it was going to be something with the PATS which I am definitely not in the mood to replace. I did actually replace the IAC when this problem started with no luck.

blhde: I have to look into getting that tool in case I run into any future problems.

Thank you both for your advice; I always get great responses from this forum.

As of right now I dropped it off at a well liked local shop called Platinum Auto. Not being someone who utilizes garages very often (sort of a do-it-yourselfer) the experience was great. The intermittent problem was due to a weak connection in the wiring harness to the engine. A wire either pulled or became corroded. Right now they are soldering up the weak points and I should have my vehicle back by Wednesday and for a reasonable price. I'm not trying to be a commercial but this is a problem that I've been battling for a while and am just happy to finally have a solution.

Final cause as of right now: WIRING HARNESS MALFUNCTION

 

Hopefully it solves your problem.

I took the ICM and stuck it in the freezer for a few minutes and that seemed to resolve the no start hot issue.

 

I did actually try this. The first time I did it, I left the hood open allowing the entire engine bay to cool. The truck started right up after I put the ICM back in the truck.

The second time, I pulled the computer and immediately closed the hood to trap the ambient heat. After reinstalling the computer, the truck refused to start. Let the bay cool for the usual amount of time with the hood open and it started.

 

I thought the ICM was an OBDI ignition part and in 96 it moved to the EECV computer.

So your 2k shouldn't have one.

 

I'm sorry I hastily read your post. The ECU was what I removed, cooled and replaced with no luck.

 

I hope to have better luck, this thing wasn't cheap.

So did the wiring repair fix the issue?

 

I wish you the best of luck with it also; I'm not sure if the wiring has fixed the problem yet. I should have the truck back by Wednesday of this week. I'm very hopeful that it will though.

I'm going to ask as many questions as possible about the location, type of damage, and wires affected so hopefully if anyone runs into an issue like this I can give some starting points for a repair or at least to rule out the problem.

Since I have yet to get the truck back, I'm in the dark about both the effectiveness and content of the repair though.

 

Just finished swapping parts and had to yank the front driveshaft, joints were making a horrific noise.


Anyway the idle was much smoother but its not really hot enough to be able to make sure the issue is resolved.

 

As of right now the problem was fixed with the most recent wiring repair. The problem resided in the engine harness connection attached to the upper intake plenum. The pin for the ignition control wire had separated and caused a weak connection and a no-start condition when the motor was hot. The solution was to either replace the harness or connect the wires with a separate water proof connection. Due to cost I chose the latter. I can post pictures upon request, I just have to find my camera.

 

Im still crossing my fingers I have fixed my 95. I do not want to dig into the engine harness.

 

I had this for awhile in my truck, and figured it to be a fuel pump problem. It turned out that after any kind of drive in my truck, if I turned off the engine and tried to start it again, it would turn over and over and over with no start (like I would have to open the throttle to give it fuel). Apparently for some reason the fuel pump does not power up right away when you start hot, you need to turn the key to on, wait a few seconds, and then try starting.

I fixed all of this and other problems, by disconnecting the battery which resets the computer, which might be a problem for you. I have not had this problem since (and this happened 9 months ago), but I also have a fail-safe stuck open thermostat as well so the engine never really heats up anyway.
And as for Ethanol, get it out of our gas, it supposedly "burns" cleaner, but it leaves behind deposits in the fuel system, on the valves, and in the cylinders, and clogs your injectors from an incomplete burn, in fact, my truck much rather enjoys running on 110 Octane race gas than on the premium with 10% ethanol that I usually do.

 

OMG am i late on that answer - new rule - no drinking and responding

 

Hey I'm having the same problem with my 91 4.0. Have spark and fuel pressure. Will run until the engine bay heats up then it will die, crank but no start. It will start up again after the engine bay has cooled. I put in a new computer and about over $1,000 in fuel system parts but I now believe it an issue in the wiring harness. I'm an army vet trying to get my college degree and this problem is ruining me. I'm looking at having to drop out until I can get reliable transportation again. Pictures of your harness would be great as I can forward them to my mechanic that comes to my house to work on it.