New to forums, desperately trying to figure out what is wrong with my 96 2.3. Dies as if not getting fuel randomly. Tested pump know it works, tested fuel pressure also good, figured it was relay swapped relays worked temporarily, wouldn't start at all used a bit of wire to jump the ground of the fuel relay that seemed to also work temporarily put in a new fuel relay and pcm relay also worked temporarily . Had every wire tested in engine harness and in relay panel came back good. It seems to only happen on extremely hot days when given time to cool down I'll get crank but no start as if fuel isn't being deleivered, had it towed to the house late one night and next morning started right up no problem on trailer. I'm being told it could be the starter relay, a bad ground wire, or the way the pcm wire runs through the firewall it's known to come in contact with the engine and cause it to stop. This apparently is a common problem with my year and engine. Has anyone encountered this and actually been able to solve it? Everything on Google and YouTube is open ended same problem but never seems to find solution. It's at the shop now and my guy can't seem to find a damn thing wrong with. Desperate for any intel on possible solutions.

 

Welcome to the forum

First thing I would do is to confirm your "theory" that it is a fuel delivery issue
Get a spray can of Quick Start(ether) or get some gasoline in a spray bottle
Next time there is a No Start spray fuel into the intake and see if it starts and then dies, that would confirm a fuel delivery issue.
If it doesn't start then no spark

Has the engine ever died while driving?
Or is this just a No Start issue?

If the starter motor works but engine just doesn't start then it has nothing to do with starter relay or Neutral switches.

Throttle Position sensor(TPS) can cause a No Start, next time there is a no start unplug its 3 wire connector and try to start engine
If TPS has an internal short it can send 5volts to computer, if engine is at 0 RPMs, then computer will shut off fuel injectors, so you would have a no start
This is called Clear Flooded Engine Mode, all fuel injected engines have this
But this is very very rare, ran into it one time

 

It has died while driving, it will be running totally fine and when I hit the pedal it's like I ran outta gas this happens randomly after about 20 or 30 miles of steady driving once it dies it'll crank but won't turn over, after a night of it sitting it'll turn over no problem, no rough idle, like there's nothing wrong with it at all, dossent matter if I'm stopped or in motion it's like the fuel pump just stops sending fuel, this is what led me to think i had a bad fuel pump the mechanic I took it to tested the psi and the pump and said it was fine, also thought it was a bad ground to the pump and hes getting 12.5 on it.This has only happened on hot days above 92 degrees ( This is the first summer with the truck.) The last week it's been at the shop hes put 60 miles on it and now it won't do it (30 degrees cooler now.). It's like something somewhere is overheating and then killing the fuel delivery. At one time putting a wire into the female part of the fuel relay and grounding it to the factory ground did start it when it wouldn't start, but after about 30 miles it died again, replaced both pcm and fuel relay had them rewired in the panel itself worked but after 30 did the same thing.

 

Change fuel filter, $10, take it off the table

Then loosen gas cap and drive, you have an EVAP system that should put a slight, SLIGHT, negative pressure in the fuel tank, this prevents gas fumes from escaping as gasoline sloshes around while driving.
If is possible for the venting system to foul up, so what happens is you get a HIGH NEGATIVE pressure in the gas tank, when it gets high enough the fuel pump can no longer send out fuel, and that would fit with the 20-30 minutes or miles when it gets fuel starved
With gas cap loose it will self vent, you should get a CEL(check engine light) and EVAP code number with gas cap loose, not instantly, it will take a bit of driving.


And fuel pressure in not fuel volume, your fuel pump could be pumping enough fuel to have 30psi idling, but under load it is slowing loosing pressure, it can't keep up
Dirty Fuel filter can do the same thing
And dirty "sock" in the gas tank can as well, the "sock" is the pre-filter, it filters larger bits from going into the fuel pump, these can get clogged up, so flow is limited and fuel pump "runs out of gas" to pump

 

That's another weird part after all these breakdowns and symptoms I've never once thrown a check engine.

 

So you're thinking I have a faulty evap canister?

 

No, thinking you should loosen gas cap to see if venting in the gas tank is the problem
Which "could" be a problem with the EVAP system, but you don't know that yet
And more likely to be EVAP solenoid stuck open not canister

 

Oh I misunderstood. I just got off the phone with the .mechanic and hes saying it's a bad thermostat or a bad water pump. With my understanding of basic mechanics I don't understand how we went from fuel and pcm relay to thermostat and water pump.

 

Your basic understanding is correct
No connection between fuel pump and cooling system problems

Does your Temperature gauge on the dash work?

If not then you could overheat your engine and it would shut off, and not restart until it cooled down
But this would be VERY BAD, overheated engines blow head gaskets and crack heads.

If temp gauge works and engine didn't overheat then I would be hard pressed to find a connection for the stalling, in a bad thermostat or water pump, there is really no connection there

 

The evap solenoid you're referring too is it also known as a purging valve? Under the relay panel driver side of the truck?