Sorry for the long post.






I have a 2002 Monte Carlo SS with the 3.8 naturally aspirated motor and ~ 41,000 miles.

About 3 months ago the car begin to die at idle, typically during long lights. It progressed to stalling while slowly decelerating as well. The car will always start right back up and no MIL is illuminated. This happened about once/day, which is 45 miles of city driving. I should note that about this time I noticed that starting a warm engine required 3 attempts. The first attempt it'll just crank. The second it'll catch and die. The third, the car will start. Cold starts are immediate. Otherwise, the car runs great, idles smooth (when it doesn't die intermittently) and accelerates fine.[/align]
As a DIYer, I replaced the IAC, removed the throttle body and cleaned the throttle plate and bore. This fixed the car for about 2 weeks. But then the stalling returned, although less frequently. Sometimes, when the car used to quit @ idle, now I'd get a stumble and the motor would recover.[/align][/align]Sothen Ialso removed the MAF sensor and carefully cleaned it with carb cleaner. For about a week the car didn't stall. Within the last 2 weeks the car has onlystalled twice (consecutively), but otherwise drives OK. [/align][/align]And although the car stalls less, while sitting at long lights the motor will still stumble and catch, with RPM's going up and down until it settles out. I noticed too that if I get off the gas quickly sometimes the RPM's drop, then shoot up, then settle to where they should be. (Sometimes, not always)

I should note that after cleaning the MAF, the warm start issue seems to have resolved itself.


I'm hesitant to bring the car to a shop because it dies out sointermittently and my guess would be the shop won't be able to do much for me, especially since
there are no computer codes. I am also hesitant to replace sensors until I stumble upon the cure.[/align][/align]After conferring with a retired Chevrolet mechanic, he suggested to replace the MAF. And although cleaning the MAF seemed to help, I am not sure this is going to cure the car's ills. Other people I have talked to have suggested everything from a crankshaft position sensor to a fuel regulator.[/align][/align]Would a faulty crankshaft sensor do this to my car? [/align][/align]I plan on replacing the fuelregulator next as it should be cheaper than a MAF and sorta seems logical, but I also don't want to waste money if the one I have is good. I was told I can remove the vacuum line and check for gas, which I did, but could not find any leaking gas. Perhaps the FPR leaks intermittently? I plan to pull the vacuum with it running and see if I can get the car to 'burp', butit's been too cold outsidelately to actually fiddle with the car. [/align][/align]Ideas? Suggestions?[/align][/align][/align][/align]

 

One ofmy buddies had an Olds. with a 3.8 in her.
Did the same what yours is doing. No codes, no lights ect.
We hooked the car up to the computer and found a bad CRANKSHAFT SENSOR.

Its not that hard to replace. The hardest part of the job is remove the crankshaft bolt if you dont have air tools.

 

i have an olds that got the crank sensor replaced at about 140k, but itsa 94, not a series2 3.8. but different motor, alot more miles, and would either restart imediately, or had to sit for atleast a few minutes.

if its using coolant i'd be thinking intake... maybe the fpr, egr....maf who knows.. and those cost money...

i'm thinking you needa get it hooked up to a scantool, wouldnt surprise me if it had a code in it. if no codes, check the fuel trims, might indicate if your regulator is leaking.