Hello all old member here with a new issue with the car.

Car is a 2000 Monte Carlo SS 3.8 150K
Modifications if i can remember them.
CAI
ZZP ported throttle body
ZZP intake insert
Ported polished LIM
ZZP front powerlog (i think thats the name the exhaust manifold from ZZP)
Random Tech Downpipe and u bend delete

All mods have been on the car since 2007.

Recent the car had started to miss fire when going up a hill or was placed under load.
Swapped out the spark plugs and wires and was almost positive that was the issue. as there was basically no electrode left on the plugs.
Drove better than it had in over a year. Guess the plugs were long over due.

Now 3 weeks later car is still running great.
Passenger side low beam goes out. i have had HID on it also since 2007 and first time they have gone out. Swap the bulb to the drivers side and it doesnt work and the driver side that was working to the passenger and the light worked so i knew it was the bulb. Instead of ordering a new 9006 HID bulb just go to the local store and pick up halogen replacements.

Also at this time i replaced the PCV valve and also what the sensor mounts to on the end of the UIM as the former plastic one was dry rotted.

Start the car and it starts right up no issues. let the car run for about 3 mins as i clean up a bit and go to close the hood and before i touch the car it dies. Didnt surge or anything just dies like i turned it off. Try to start the car back up and it starts no problem but will not idle at all. Start it again and hold the rpms at 1500-2000 and it runs and sounds fine no miss fires and no issues. hold the rpm for 30 seconds or so and see if it will idle on its own the rpms start to surge and drop. from 300/400 up to 1500 rpm with out touching the gas. does this maybe 4-5 times then idles fine again. so i get out and look around the engine to see if anything sticks out to me nothing that i can tell. then car dies again.

Same thing again i can start the car fine but then dies. Start the car and hold RPM at 1500 and no issues. i release the gas now and the car dies. and wont idle at all on its own.

Please help. I am thinking its something to do with the PCV valve but didnt think that would mess with the idle that bad.

 

Maybe these posts have something in them that might help
click--> https://montecarloforum.com/forum/en...control+module
click--> https://montecarloforum.com/forum/en...control+module

 

I just had a similar situation with my Monte. I replaced my ICM and coils (got some from an L67) and it so far has taken care of the issue.

Here's what I recommend. Remove the ICM with the coils and then take each coil pack off (5.5mm bolts) and look for corrosion. If you find some (mine was a lot) clean it up and put everything back together. If that doesn't work, let us know.

 

Found my issue.



Ended up checking the connection on the MAP sensor because that was the only thing that i had disconnected this past time and noticed that the top of the sensor didnt seem to be sitting right. well take it off and see that the sensor is in 2 pieces.

Replaced the sensor and runs like new.

 

Glad you found the issue!!

 

That's great! Thanks for coming back on to let us know how you fixed it.