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Discussion Starter · #1 ·
I have an 88 Trooper II.... Ran Out of Gas and the Problems Started...
Would not idle... Fuel filter was clogged... Replaced it got a little better... but was missing and wouldn't accept fuel... jerking around... Dropped, Flushed and cleaned gas tank, cleaned screen on fuel pump and replaced fuel filter again.. Still bumping along. Now Uneven idle from 900 to 1900 RPM's... and have to keep my foot on the pedal to keep it alive, and have to get it up to about 3000 rpms just to go with out the jerking and lunging forward... Replaced Plugs and checked the Dist cap and roter... no change... Cleaned the throttle body and mass air flow sincere... "Now" idles around 500 rpms on it own, but has a bad miss that will kill the engine. Replaced the Mass Air flow sencer... cranked and ran ok for about one minute... Bad Miss is back... now it won't idle... am I in trooper hell? can you help me!!!
 

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being that it is fuel injected, what is probably happened is you injectors themselves have been compromised.. and by compromised i mean becomed either cloged or partialy blocked... What happens is instead of a nice "fan" spray or mist :) , the injector "pees" in the manifold (if at all) causing more fuel to go to one cylinder more that the other, causing a very ruff idle and or poor starting :evil: . being that your fuel filter was clogged shows there was a fair amount of debrits in your tank, I would go to a shop and have the injectors cleaned, fuel line flushed and filter replaced again... this seems expensive :roll: , but is a fraction of the price of replacing your injectors all together. hope this helps....
 

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Discussion Starter · #3 ·
Brought my trooper to the shop.... flushed fuel system and replaced the fuel pressure regulator.. Still hard to crank, but after I drive for a while it will idle.... now it seams like it just don't want to go... while driving, if I'm running along at 45 and I floor it, there is no change, no Pickup... RPM's sit at 2500 no matter where I have the peddle. Troopers aren’t fast but I'm being passed by old ladies, and it drinks gas like you would not believe... at this Point I have replaced the Fuel Filter 3x's, Plugs 2x's(they keep fileing out), Mass Airflow sensor, Dist Cap, Fuel Pressure Reg, EGR Value and transducer, some old vac lines, PCV Val, Injectors (Used ones, One of the tips of the org. was cracked), Checked my timing... I am what you might call Lost!!! I still believe this to be Fuel but.... any Ideas ??? Pls.... Help! :(
 

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At this point I am thinking the only thing left is the pump itself. Possibly running it starved (the socked plugged) compromised its function.

Rather than automatically assuming this though I would at least put a fuel pressure gauge on the rail. I suspect the readings will be close at idle but too low at load as the pump just cannot keep up.

You might also check the external pump wiring for a bad connection (i.e. one that only has partial continuity). This would be a much easier fix than redropping the tank. If you can get some specs and an ampmeter you might also try getting some readings here before dropping the tank. That might tell you alot about the pump condition.
 

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Discussion Starter · #6 ·
Tested Pressure at the rail.... only around 20 PSI at 1000 RPM's around 40 at 3000 RPM's... Thankfully I was able to test another trooper "1990" pressure at the rail was aroud 95 PSI??? Tested behind the Pressure Regulator Mine at 1000 rpm is 20 psi, but at 3000 rpm's it' around 40 psi??? the same as at the rail..... Is this a Pump or an Altenator issue I was reading about???

and Yes, "Fouling" .... with all the missing and back fireing... they looked old used Black with carbon build up etc...

Thanks for all the imput... really I feel lost here...
 

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Discussion Starter · #7 ·
New Fuel Pump, and still only get 40 psi at Fuel Rail..... :( Lines look Good Help.... Alternaor??? Could it be? I've already Spent the money for my lift :cry: please any ideas??? Thanks
 

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what is the correct fuel pressure supposed to be?? Make sure you do not have any vacuum leaks at all, check those vacuum lines twice man. Pay close attention to the fuel pressure regulator vacuum line. You mentioned messing w/air flow sensor and worked better for a minute or so...check connections to it carefully and make sure there are no air leaks on its plumbing...good luck buddy!
 

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Well so much for my bad fuel pump idea. I suppose it could be the alternator. Easiest way to check would be to run a temporary new line from a 12v source to the fuel pump. If the trouble goes away, alternator or relay problem. If not then seemingly not the alternator. Again this is just some temporary in the driveway test. You really don't want a hard wired fuel pump in case of an accident.

Any chance all the other work messed something up. Say for example plug wires reinstalled wrong??? Wrong dist cap??? Harmonic balancer slipped??? Basically grasping at straws but maybe it will jog something and get you on the right track.
 

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Discussion Starter · #10 ·
Thanks for the ideas.... I will try tomorrow... Just getting in and havn't touched it at all today. My Plan is to go back over everything as well as replace my V Belts tomorrow..... I will check my vacume lines again, and try hard wiring the pump.... I have to be looking over something. all in all I'll learn alot off of this.... Thanks agian for all the imput.... You guys are great... I'll keep you updated as well as ask more questions.

Thanks again
 

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Discussion Starter · #12 ·
EagleCap said:
I-TEC fuel injection. At idle
With vacuum hose removed from pressure regulator - 42 psi.
With vacuum hose attached to pressure regulator - 35 psi
Where is this check done from??? at the Rail or Before/After the Regulator?
I got the Book and I belive this test is after the Reg. (The Return Line)
if so I only get around 20 psi at Idel now if I bring the RPM's up to Say 3000 I'll get 40 psi the hose vacume hose dosn't seam to change anything..
and I have replaced the regulator... I haven't worked on it much for the last two days.. ok at all.. But tomorrow I will be back at it..
Thanks....
 
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