Occasional stall at idle (550rpm)

GMike · December 11, 2003

Any ideas what to check for this? I have a 2002 Escalade with around 60K miles. I have recently had the fuel filter replace, new Bosch Platinum +4 plugs, changed oil to Mobil 1 (w/Fram doubleguard filter). The truck runs strong, but after it gets warmed up and I come to a stop, the idle starts to drop below 500 RPM's. The PCM seems to catch it some of the time, and tries to keep the engine running, but occasionally it dies. I put it back in park and she starts right back up. Unfortunately, it just seems she wants to idle at too low an RPM.

I have a preditor programmer and can change a few things, but not idle (not for 2002). Any suggestions as to what to monitor, and or change? I also noticed the knock sensor retarded timing at WOT. So, I richened up the fuel mixture a little bit. So, far no difference regarding the "idle stall" problem when using the stock program or the preditor programmers standard performance tune.

Your help and suggestions are appreciated.

GMike · December 12, 2003

I was given a link to check for PCM calibration updates by entering VIN:

I ran my VIN and the Engine Calibration mentions a "New calibration to address idle surge condition caused by throttle body coking, to be used in conjuction with throttle body cleaning."

So, I will use my programmer to see if the CVN# 0000E4E8 shows up in the PCM. If not, I guess I will need to shop around at a GMC dealer (Cadillac is too expensive). I would think a chevy/GMC truck shop should be able to do both procedures, recalibrate and clean.

Any other suggestions?

GMike · December 13, 2003

Here is the update...if anyone cares I purchased some throttle body cleaner for $2.50 and cleaned as much of the intake and throttle body as I could reach. Problem solved! Idles perfect now at around 600 rpm. NO MORE STALLING! Happy man now.

Side note: Throttle body and intake (chamber just past throttle body, in the engine) were completely covered in black varnish like soot (coke). Sprayed so much cleaner into to the engine it was pooled up inside the engine, passed the trottle body. So, I rolled up a cloth diaper (usually use for polishing) stuck it into the engine passed the butterfly intake, left it in there for about 10 minutes while I continued to clean. Pulled it out, after it soacked up most of the cleaner. It also helped to scrape away more varnish on the way out. Diaper is now ruined, and completely black. Small price to pay for a clean and properly working throttle body.