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Discussion Starter · #1 ·
I have an 88 Isuzu Trooper (2.6l 4cyl) that isnt starting. It turns over, starts, idles for 5-10 seconds, then dies. I originally thought I might have a head gasket problem, but I drained the oil today and replaced it, and its clean. The temperature here is reasonablly warm right now (50s-60s) so I dont think its suffering from some of the "cold start" problems I've read about.

I'm not sure where to look next -- Perhaps the fuel pump? It would seem to me though, that if it were truly a fuel pump problem, it wouldn't start at all. Does this make sense??

Anyone who has any suggestions/advice, I'd appreciate it. I'm really hoping to salvage this thing. I have a 90 trooper that I bought as a parts car (if I can get this pig running again, I'm going to replace all the doors, which is another project since going from manual-> electric windows)

Give me some advice, puhleeze :D

-=\Blu/=-
 

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Hi,
I am working on the same problem i think. I plan to devote the day tommorow to it, as I have killed my '96 Trooper (see my other post). I'll let you know what I find. One thing to start with is vaccum leaks. There is a large hose under the intake that can just be reached through the pass. side wheel well. Mine likes to come off and cause the symptoms your are describing.

Adam
 

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Discussion Starter · #3 ·
Adam-

Thanks for the reply, sorry to read about your 96 :(

I took a quick look last night at all the vacuum hoses... didnt see anything obviously disconnected, but I'm not sure I was able to find the one you were talking about.

Be interested in finding out how your troubleshooting of the 88 goes.. keep me posted :D

-e
 

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Discussion Starter · #4 ·


Here's the culprit. The driver side door is smashed right now, and I've replaced the back doors (dang rust) with the ones from the beater. If I can ever get this thing started again, and running with some consistancy, I'm going to replace all 4 doors (all kinda rusted @ bottom) with the ones from the beater.... and maybe even get it painted :D

-Blu
 

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I'm going to suggest that you check two things:

Alternator
Engine Relay

The alternator energizes the engine relay, which powers the fuel pump. When you turn the key to start, it bypasses this system and sends power to the fuel pump. Enough fuel pressure builds up for the truck to run for about 5 seconds.

-Tad
 

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well i had a problem similar to this on a 1.8L in my luv. It would start and run whith no power at all and stall all the time. I changed the fuel filter and no problems. Might whant to start whith that cheap part first :)
 

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Discussion Starter · #7 ·
mepr said:
well i had a problem similar to this on a 1.8L in my luv. It would start and run whith no power at all and stall all the time. I changed the fuel filter and no problems. Might whant to start whith that cheap part first :)
Yeah, was thinking that. I'll swing by autozone on the way home (if they let us out early today) and snag one. The added bonus, tho, is I have the beater trooper (blown 6) so if it does turn out to be fuel pump, out-of-pocket should be nominal. (And, the people who had the beater before me took the time to cut a hole right above the fuel tank so I can get to it from inside the truck.

Thanks for the tip, will report back.

-Blu
 

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I hate to break it to you, but the V6 and the I4 have different fuel pumps. The pressures used are different. The I4 with its multi-port fuel injection requires higher pressure.

I'd put a volt meter on the fuel pump connector and watch to see if it looses power as soon as the key is released. If so, check the items that I mentioned above.

-Tad
 

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Discussion Starter · #9 ·
Tad said:
I hate to break it to you, but the V6 and the I4 have different fuel pumps. The pressures used are different. The I4 with its multi-port fuel injection requires higher pressure.

I'd put a volt meter on the fuel pump connector and watch to see if it looses power as soon as the key is released. If so, check the items that I mentioned above.

-Tad
Ya... I hadnt thought of that. Oh well. Anyone need a fuel pump for a 6? LOL - Thats a great suggetion tho.... I'll add that to the list of things to try tonite. Seems really odd tho.... that would mean that any time your alternator was going, you wouldnt be able to start the vehicle? Is this something specific to this engine, kuz I've not heard of that before.

My father reminded me this morning about his 73 vega.. he rebuilt the engine because it was running poorly. After the rebuild, it was still running poorly. At that point, he replaced a blown fuse and all was well. Lesson learned: look for the little stuff. :D

-E
 

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Bluphant said:
Seems really odd tho.... that would mean that any time your alternator was going, you wouldnt be able to start the vehicle? Is this something specific to this engine, kuz I've not heard of that before.

-E
Yup. Those of us who have learned it the hard way carry a 2" piece of wire with which to jumper the engine relay on (this can be done at the alternator wiring harness by jumpering the 12V input to the output that connects to the engine relay.

There are worse places to be stuck than at your girlfriend's house though :wink: We are married now, and the alternator excuse wouldn't help me explain why I came home late - she learned that there was a fix the same time I did.

Good luck,
Tad
 

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Discussion Starter · #11 ·
OK.. heres where I'm at. I replaced the fuel filter... now I have to find some wire ties (!) to hold it in place.. is that normal? I'm wondering if someone worked on this prior. (answer would seem to be yes)

The trooper now lasts quite a bit longer than it did ... starts, stays on now maybe 15 seconds, 20 seconds before it putters out.

Couple notes- the battery light and the O2 light both stay on when the truck is running. Lends credence to the alternator-jumper bit. I'm trying to figure out exactly what you mean by jumpering it..... sorry for my lack of understanding. Could u give me a little detail?

The O2 bit is another story I think.... prolly needs replacing as well. As a side note, this project has been haunting me for almost a year... it's probably been a year since I had the thing on the road... so it's been sitting for some time. I've occasionally juiced it up, but it's been pretty stationary for some time.

Thanks for all your help

-e
 

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No, the V6 alternator won't work. The battery/o2 light are indicative of an alternator problem. You could take it and have it tested.

On the alternator connector there are 3 wires.

I can't remember which two to use off-hand, but the 12V constant one should be easy to find. The other two are probably ignition (also easy to find) and the one that you need to jumper to 12V (ignition).

-Tad
 

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Discussion Starter · #14 ·
Cool. I'm workin on it now. The truck exhibits the same symptoms with the alternator disconnected.. so there we have it. Workin on the jumpering bit now to verify.

-e
 

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Discussion Starter · #15 ·
Gettin dark and cold.... will have to wait until the weekend's over. Oh well.. at least I made progress! I'm convinced now that it's just the alternator.... thanks for your help with this... I NEVER would have guessed this, given the symptoms. I'll post updates later next week.

Next project.... add a HD to my wifes PC :) Hint: NEVER buy maxtor.

-e
 

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Discussion Starter · #16 ·
New alternator purchased...looks right. Getting the old one out of the 2.6 is a bitch and a half tho. LOL. Seriously tho- if anyone is in the NY metro area (I'm in CT) and needs parts off the junker (90 Trooper) PM me here and we can work something out. It has to go (per the missus) pretty soon, so......

-e
 

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Discussion Starter · #17 ·
Tad-

You rock. It lives! Running a bit rough (to be expected after sitting for a year) - but it's up & running! I replaced the alternator, found the set of keys that I DIDNT leave at the inlaws over the wknd (gasp) and lo & belold, it runs. O2 light now off, seems good.

Only odd thing is the temperature gauge never went off low. It'd always worked in the past. Maybe I messed something up while installing alternator.

Anyways, thanks so much for your help, I'da never come up with that on my own.

-e
 
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