Hey guys I have a 95 Dodge avenger Auto, We can't seem to figure out this bad idle problem, it isn't extreme but it is not right....When you drive it it feels strong.

Did a compression check and it seems to be even across the board



Idle is around 750 and things we changed is and checked are.

IAC sensor
TPS
Map
Vacume lines
o2 changed
Plugs
Wires
Coil
ECM

I've even tried hooking up my snap on scan tool, it's doesn't even comunicate with it for some reason.

Anyone can help me it would be appriciated

WOW no one at all??

well man, i think noone has responded because you have already replaced/checked the usual suspects. only thing i can guess at is a stubborn vaccum leak somewhere. could also just be something in the ECU perhaps. my car normally idles between 820-855 or so, but somedays it decides to drop down to as low as 780. moody i guess.

1997 Silver RS
Wiseco 8.8:1 Pistons(back to low compression!)
Eagle Rods
T3/T4 Turbo
Custom FMIC
Greddy Exhaust
440's
Most current 1/8th mile time: 8.3@90mph 2.015 60'(Nitto Drag radials, i suck)

Alright.. you never really told us what the problem is.. describe the rough idle..

Stage III HRC
8.5:1 compression
12 psi @ 2300 rpm
fully built engine..
oo.. and it goes vroom

best et. 14.49 @ 101

Yeah a description of the rough idle might help.

You have checked the usual suspects, here's a few unusual ones:

How's your fuel? fuel filter? pressure regulator?, any leaks?
Check the seals around TB, intake manifold: upper & lower, and intake manifold to the head, as well as o-ring seals around the injectors.
Don't discount an exhaust leak as well, check the gasket at the exhaust manifold to head for leaks, as well as at the cat, etc.
EGR system (if you still have it) could be stuck open or closed and messing things up.
Cam and crank sensors.

now I start to reach:
knock sensor, reading strangly and playing with timing

There's always the standard compression test (which I don't remember seeing in the list).



15.9 @ 86.7mph

Smooth idle? We don't need no stinking smooth idle.

Mods List:
http://highlander.dsmpower.com/sig.htm

Also, a couple of people have gotten better idle by installing better battery grounding cables.


95 Eclipse RS : 5 speed
15.901 @ 88.34mph
Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html

the idle isn't really BAD BAD.....motor has a slight shake to it..and the exhaust goes PUTT PUTT PUTT

I checked compression and it's all the same numbers...I have had an ASC mechanic look at it and he said the timming belt looks like it could be bad causing it to be stretched a notch or two...

There are no EGR codes and other wise the car goes good...it's just at idle...and I checked the TB and ALL gaskets including exhaust and intake...