1997 dodge avenger es 2.5L

ok so when my car is at idle, it feels like its missing a couple of "beats" per say. the car has a slight shake. when im driving everything is fine, but when i come to a stop, the rpm's drop from about 1000 to 700 to 200 to dead by the time i stop. if i shift my tranny into neutral, it will still do it (and i know its out of gear) BUT. when i shift it into neutral, and rev the engine, it runs normal. i need to figure out what the hell is wrong with it. i have been up all night figuring out why my SRS system is lighting up, and now this problem...its bugging the hell out of me. oh, and it doesnt throw any CEL lights or error codes. and i dont know if it matters but it has been running on 87 octane...

 

well, it wont die anymore...but the rpms still go to 200 when i stop...i think it might be the PCM "learning"? what do you guys think?

 

That Might be your problem running such a High grade fuel. 83 Octane WOW! I only had one situation like this when I was being cheap when gas was $3.00 I found this gas station sellin it for $2.15 come to find out the gas was watered down![:@] so every time I had to stop I had to first put it in neutral rev it with my right foot hold the brake with my left then keep it a 2,200 - 2,500 rpms then hurry up and shift into first, and reverseing the car I was better off pushing it into reverse. But I think your car is running too rich so to speak and the computer is cutting back on the fuel. I might be wrong does your car have any mods to it where you need Octane to keep it running. Try running unleaded (if I spelled that right) then work your way up from there.But just driving with 83 Octane for every day driving WOW! you must have some deep pockets. I hope I helped!

 

87 octane is the lowest of the three common octane ratings (87, 89, 93) and you can only get unleaded gasoline (clean air act banned leaded gasoline in 95). no i dont have any mods to the car...

 

was the fuel filter ever replaced? if not that might be a place to start.

 

check ur plugs and wires, make sure the spark plug wires are wired up correctly

 

Definitely sounds like a tune up issue. Perhaps carbon buildup? Have you tried to do the "Seafoam or MCCC" cleaning? Both use the same process...the links are about different cars but it's all the same in the end
What kind of oil do you use? "Weak" oil can cause more friction than you'd want in the motor.
You just changed your CPS right Jakbob? Did you put the paper spacer in? The CPS can also cause issues like this at lower RPMs.

 

well, i took my car to my friends job to scan it (hooks up to obd 2 and tells me the data when the engine is running...) i have a vaccuum leak...kinda small...but when i disco'd the battery to try to turn my SRS light off...i think that when the pcm was learning again, the vaccuum leak messed it up...i say this cause at idle, my pcm thinks my intake temp is 214 (not a typo) and my tps sensor is at 26%. the problem is...i cant figure out where the leak is coming from...its definately coming from the throttle body area, i checked the vacuum lines...but i think it might be my egr valve leaking or even my throttle body gasket...or my brake booster line...i dont know how to test it and the fact that my intake plenum (v6) is close to the firewall, it makes it really hard for me to put my huge arms and hands back there...my friend with small hands already burned the crap out of his hand on my egr return line...

 

i fixed it. it was the gasket for the egr...replaced it, runs fine...

 

Soory so late been busy. Just Like to Give myself the DUMBEST RESPON REWARD! didn't fully read the question b4 I replied and would like to apologize.