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Hey Van just found this website and it seems to be a good tool for "the home mechanic"
I know you work with light trucks..etc but, maybe u can help me out with this problem as noone else can...or has...yet haha..
I have a 95 monte carlo it has the dreaded X motor in it...3.4L i picked the car up for 1000 bucks..it ran okay..but not great...i researched some common problems on this motor and it turned out to be..intake manifold gaskets ...so i replaced those..hoping this solved the problem..i started it up and...no change at all...
so i decided to scan the computer for codes...it was throwing off a mass air flow sensor code...i replaced that with a brand new one and reset the code...but, it is still comming back as a MAF sensor code...and it is reading 0 grams of air...i talked to a GM mechanic at a local car dealer ship he said...check the vacuum lines....i replaced every one...i also replaced Idle air control
Throttle positioning sensor
Air intake temp sensor
and even the air filter..
Still it runs very bad....
what it is doing is...when i start it..the idle goes to about 2 grand and drops suddenly to 500 rpms and up to 1500 rpms...and fluctuates between them 2 for about 10 seconds then goes to about 100 rpms and smooths out...also.. when i am driving as you know (in an automatic) when you let off the gas while driving...the idle is supposed to drop to about 1000 rpms or so...well what it does is stay at 2000 rpms..and when i am off the gas the idle will drop real quick...almost as if the car is shutting off but then jumps right back up to 2000 rpms...and you can actually feel it also...escpecially when on the brakes...another symptom is when i am at a red light on the brake...if i was to let off the gas the car pretty much goes without me hitting the gas...and it goes quick...almost like the idle is stuck open...i cleaned the throttle plate and everything....i was told by someone that it COULD be a alternator going bad...or a tourqe converter switch not engaging or disengauging....whats you input on this?
If you need ne more info to help your decision just send me an email...
Thanks for your time...If this has nothing to do what you know as far as chevy's srry for botherin ya :)
thx again...
Answer -
I would check to see if the MAF sensor is getting the 5 volt refference signal.
You could have a blown quad driver in the ECM.
Van
Yea, it is gettng the 5 volts...i was told torque converter switch? would u happen to know if this is located on the outside of the tranny or would i have to drop the pan....
oh, and whats a quad driver...srry im not familiar with the ecm components....
Thanks again for your time!
AnswerI don't know where the torque converter switch is.
A quad driver is a transistor in the ECM. There are four of them, for different sensors. That's why it is called a quad.
Yours must be good if the voltage is there.
What kills them is testing them with a test light, which can draw more amps than they can handle.
Van
