Isuzu SUV Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter · #1 ·
I've got a '99 Trooper that is dying what appears to be from fuel starvation. Symptoms include:
1) The engine will idle but will dye either after a minute or if the accelerator is pushed.
2) After a minute of playing the engine will not fire at all. If it rests for 5 minutes then I can start the car for a minute or so.
3) A mysterious new engine knock appeared under the slightest load just before (5 miles) this happened. I've burned a 1/2 tank since the last fill up and didn't noticed this knock before.
4) It just didn't run right in the 5 miles before this happened. It didn't shift right (a bit early and erratic) and it seemed to have small dead spots in the power.

What I've done:
1) Put a can of dry gas in (Hail Mary play 1). No help
2) Put a new gas filter in (Hail Mary play 2). No help
3) Watched the fuel pump squirt into a jar very aggressively while key is on, looks like the fuel pump works.
4) Found a P0101 code pending. Bought a $100 MAS. It WORKED! ... for about 1 mile then the same problem came back. I still heard the knocking before it failed.
5) Checked the intake hose between the MAS and intake manifold, looks very good.
6) Hoped the MAS was simply defective and exchanged it under warrantee (thanks Autozone. Hail Mary play 3). It works again, however, I still hear that spark knock pinging, the shifting isn't correct, the power isn't smooth, and the idle is at 2500rpm (maybe the computer is still learning?). I'm very confident in the next 2 or 3 miles it will die again. I'd like to try some diagnostics while it's still able to run for more than 60 seconds.

In the last 6 months I've:
0) Changed all fluids. (1 month)
1) Put a new EGR in. (3 months)
2) Changed the plugs. (5 months)
3) Recharged my K&N air filter (5 months)
4) Replaced the intake manafold gasket (8months)
5) Cleaned the EGR passages (1yr ago).

Thanks - Phil
 

·
Registered
Joined
·
7,209 Posts
Are you not getting any codes? Which intake manifold gasket did you change? Was it paper or thick plastic?

Joe
 

·
Registered
Joined
·
894 Posts
I too would look harder at the fuel delivery and electrical systems.

For the fuel pressure regulator (FPR) try turning the key to on and leaving it there a few seconds before turning all the way to start. That powers the fuel pump before cranking and will refill a fuel rail that has bleed down due to a leaking FPR. Easy to do and could highlight a problem FPR. Other test is to remove the vacuum line on the FPR. If you smell fuel the diaphram has a leak and you need a new FPR. Next, I would invest in a pressure gauge and install it on the fuel rail and see what is really going on. Many the pump will work fine with little or no backpressure (i.e. into a jar) but act up under pressure or over time.

I'd clean and inspect the battery connections (I know it starts and that should rule out the battery per se as the problem) but funny things can happen. Leaving it so disconnected for 30 minutes will also reset the computer. Like you noted maybe it needs to relearn how to run with a good MAF sensor. I'd put a voltmeter on the battery to verify the charge. I'd next turn on the parking lights (radio or something else that will noticeably cut in and out) and wiggle on the main wires to see if maybe there is a short/break issue. After that I would check all the underhood wires for a unhooked, broken cracked, etc. wiring problem. Next, I would open up the fuse box and look for any corrosion or bad fuse connections. I'd probably consider swapping around engine fuses/realys for accessory fuses/relays of the same size and type. Next, I would start it up and check the alternator output.

Just my $.02.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #5 ·
Joe - The only code was a P0101-pending. I'm not 100% what the pending means, but the scanner said it was a Pending Code. I was still under warrantee when it went bad so the dealer did it.

Tom/Amigo - Thanks, I'll drop the $40 on a fuel pressure gauge tonight and start investigating the FPR. I reset the computer last night and put my charger on the battery all day (lots of cranking was done). I'll double check the voltage, alternator, and connections. I have seen an intermittent P1870 code over the last year and tend to check the voltage regulary because this can be a low voltage issue as well.
 

·
Registered
Joined
·
149 Posts
Try driving without the gas cap or with a loose cap. If the cap is not venting properly, it will create a vacuum in the tank and cause fuel starvation.

Regards,
Tom
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #7 ·
I cleaned my Plenum chamber last year, but will check the area around
the IAC solenoid. Thanks.

New information:
- The car won't start now unless I unplug the battery for a few
minutes first. Then it will run a few minutes and die.
- I'm not getting any ODBII codes anymore.
Any change the computer just simply be wacked?
 

·
Registered
Joined
·
4 Posts
Did you find the fix??

I think I have a similar thing that your truck did. My 02 axiom has 67,000 miles and sometimes if it idles for a minute the check engine light comes on and the fuel gauge goes nuts... and it even dies while driving down the road.

I'm curious if you found an answer to your problem.

Thanks
Scott
 
1 - 8 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top