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1990 Trooper starts but dies immediately

970 views 6 replies 4 participants last post by  Ebola Zaire 
#1 ·
Hey guys, hope someone can help me. For the first time ever since owning it my crazy reliable Trooper is not running.

1990 Isuzu Trooper 2.6, Manual

Headed home late Saturday night. Felt Trooper kinda shudder, then check engine light flashed on and it stumbled then continued running normally again (never done anything like this always has run very very strong). Came to the next stop sign and suddenly it was sputtering and barely running. I managed to make it the few blocks home only able to run at about 15-20mph. It barely made it, this was all in first or second, gas pedal all the way to the floor. Engine also seemed to be lugging like I was in too high of a gear. Yesterday I checked the code and it threw a Code 44, lean condition. I feel like it was getting starved for fuel. Now I can start it and it will run for a second then sputter out and die. Will start every time and sounds good for literally a second or two then dies every time. First I thought my alternator went, it's a recently "new" Oreilly special... but I jumped the relay and it still won't run. Nothing changes with the relay jumped. Fuel pump is clearly running. I checked the fuel filter, which seemed very plugged up and changed it for a new one while I was down there. But problem still persists. I attached a fuel pressure gauge to the outlet line, but before the fuel pressure regulator because I could not get the line off after it. It reads 20 psi when I try to start the engine or jump the fuel pump relay. A steady 20 psi...

So fuel pump went out? Could it suddenly die like that but still be able to pump at half the psi? That is what seems strange to me. No symptoms prior. :?

Thanks in advance for any help!!!
 

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#2 ·
Sometimes you get a little heads up when it stumbles occasionally for a few days. Sometimes it just shuts down never to start again(until your replace the pump). I dealt with it on the pickup I had. It went through 3 fuel pumps in the roughly 1 1/2 to 2 years i had it. It's one big reason i went the carb route with the trooper i have now. One thing you could check is the hose between the pump and the pump bracket. If it wasn't fuel injection rated it may have come loose or gotten a hole.
 
#3 ·
Thanks for the quick response. My wife's car's fuel pump suddenly went out once. I had to change it in the parking lot at her work, she went to turn it on after work and it wouldn't run. Luckily that pump was easier to access. I will more thoroughly inspect all the lines but as far as I can tell everything is secure, no visually leaking gas or smell. I clearly hear the fuel pump running it just only seems to pressurize the system to 20psi...
 
#4 ·
Could be fuel pump or the alternator. Do a search on here for the jumper test.

Yes that is common for them to die like that. My 1st Trooper I backed it out of the garage and that was it. I had to replace the fuel pump.
 
#5 ·
Thanks for the responses. I still have not made progress... but if the alternator is bypassed with the jumper it will produce enough fuel pressure to run right? Since jumping the fuel pump relay does not make it run can I assume the alternator is good? Could the strainer on the fuel pump be so clogged its not producing full psi? Its weird the pump is coming on but pumping 20psi
 
#6 ·
You are correct on your jumper. Doesn't guarantee your alternator IS good but does pretty much guarantee it's not your alternator that's causing you problems if that makes sense. You are bypassing that circuit in the alternator with that jumper.
Mine did exactly the same as yours. I've posted before it was the very short hose that connects the pump to the hard line, all in the tank which I think mustang999 is also referring to. Yup, pump ran but that short piece of hose was a tar like mess and half the fuel was making it to the fuel rail the other half was recirculating in the tank. Great you have a fuel pressure gauge, I've got the same one and it has helped me over and over. Trust it, really no need to even try and start the truck until you get that fuel pressure corrected.
 
#7 ·
Hey guys thanks again for all the responses. I just wanted to follow up that it was the fuel pump, I cut an access hole which made the job easy and now it running great again!
 
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