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Discussion Starter · #1 ·
http://www.turbododge.com/forums/f4/f14/138458-help-poor-idle.html

would this apply to a NA motor also? because my 94 shadow base 2.5L had idling and running issues these past few weeks. yesterday i don't know exactly what i did, but i suspected a vacuum leak @ the intake manifold.

i had a vacuum gauge hooked up to the vacuum source, the speed control nipple @ the brake booster and it showed i wasn't pulling enough vac.

i replaced any dried/brittle/broken vacuum hoses, ran a smoke machine through the lines to check for leaks. nothing. popped everything back in and it ran fine. ALOT better than before and the vac gauge showed i was pulling enough vacuum.

i run to my sisters house and the car started to relapse, but the symptoms weren't as bad as before. before the idle would be surging and dying out on me @ a stop light, but would NEVER die. but since i find it annoying that the car shakes so bad when undergoing the idle search i lay on the gas pedal.

since i've somewhat fixed the problem, i'm still having slight idling problems, only not as bad as before.

i've already timed the motor. i haven't scanned for codes yet though.
 

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Yes the procedure will work on an N/A motor, just a different T/B.
Usually they will not surge unless the controller is seeing something and it is quickly trying to correct the condition.
Check codes first, and be sure all basics are correct(no ignition problems,etc.)
Was your ignition timing off? If so it is possible the cam timing is off. Ignition timing will not change by itself.
 

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Discussion Starter · #3 ·
CODES:

37 PTU (TCC) solenoid CKT-open or short
22 coolant temp sens voltage too high
24 TPS voltage higher than max limit
25 AIS motor and/or driver circuits
27 injector 1 control ckt fires imporperly

37 is expected; the car used to be an automatic.
 

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I am assuming the code 22 was set when you checked the timing.
Clear the codes, and drive the vehicle and see what returns, you have 3 serious codes there, we do not want to chase any false codes.
If they all return they may be related by a wiring issue and you will start with the lowest code # first which is the TPS (assuming the CTS code 22 was set when doing timing)
 

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Discussion Starter · #7 ·
further testing has isolated the system causing the idling issues.

the egr system.

i completed the egr system test as stated in the fsm. it says to idle the motor then goose the throttle and watch for egr valve movement. i saw none. i pushed down on the egr stem and the idle smoooooooothed out. i'm thinking the egr valve might be stuck open causing exhaust gas to flood the intake.

further diagnosis: while idling i unplugged the vac line to the egr and the idle smoooooooothed out. the stem had retracted (egr closed). so now it's not stuck or stuck at all.

i popped a hand vacuum pump to the vacuum motor (the egr nipple) while the car was running. applied vacuum and saw the egr open/close depending on vacuum levels. now it looks like the egr isn't stuck at all. good thing otherwise that would have been an 80 dollar mistake if i had replaced the egr.

the egr vacuum motor does not leak vacuum either. i've applied vac to the egr and pinched off the line and the valve did not drop. it dropped only when i released the pinched line. my hand pump leaks so i had to pinch the line.

the fsm states that it would be a defective egr control system that would be causing my problem. plugged passages.

it tells me to remove the tb and inspect the passages and clear out any blockage. i haven't done this yet. BUT what about the backpressure transducer? couldn't that be @ fault?

because when i began the tests the egr stem was open, so couldn't the transducer be holding the egr open for tooo long of a time?

i'm gonna go drive around to see what happens.
 
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