GMike Posted December 11, 2003 Report Share Posted 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. Link to comment Share on other sites More sharing options...
BenKey Posted December 11, 2003 Report Share Posted December 11, 2003 If you paid to have it done and it wasn't doing it until you had it done, then I would take it back. Link to comment Share on other sites More sharing options...
SSminneapolis Posted December 11, 2003 Report Share Posted December 11, 2003 Link to comment Share on other sites More sharing options...
BigTex Posted December 11, 2003 Report Share Posted December 11, 2003 Don't the predators act as a logging / diagnostic viewer as well? If so, can you look at your PCM idle speed with it? The dash gauge is too slow to get accurate results from. It sounds like your idle speed is set too low on the custom tune. Check the idle speed with your custom tune at cold start and at hot running conditions. Then load either of the other programs and look at the same values. It sounds like the custom tune has too low an idle rpm at operating temps. Also check it with the AC on and off, and in park vs in gear. Generic info: The PCM adjusts the idle per different operating temps. There are 4 tables: in gear AC off, in gear AC on, in park AC off, and in park AC on. There are higher rpm idle values in the cooler temp cells (like 850 rpms), then as the truck gets warm, the PCM throws idle back to lower rpms (about 550). Do you have an aftermarket cam in that Escalade? Richard Link to comment Share on other sites More sharing options...
GMike Posted December 11, 2003 Author Report Share Posted December 11, 2003 No aftermarket cam. The predator programmer tune has no effect on the idle stall problem. It was doing this before I got the programmer, with factory cadillac PCM program. I have found other people on the GM-trucks website with the same problem in their 6.0L V8. Someone suggested throttle body cleaning. Other's suggested going back to GM for new PCM calibration update. I have/can use the programmer to monitor live data at idle. The RPM fluctuates between 550-590 RPM's. One guy describes his problem the sam as me, except he noticed it only stalls when he is coming to a stop and the power steering is active. In otherwords, at or nearly stopped and turning, or stopped and AC compressor kicks on. Apparently, causing enough added load to cause the erratic idle to finally stall. I wish I could figure out a way to raise the warm idle about 50 rpms. Link to comment Share on other sites More sharing options...
GMike Posted December 12, 2003 Author Report Share Posted December 12, 2003 I just had a thought...does anyone know if changing the timing (advance or retard) will effect the rpm's at idle? I can use the preditor programmer to do that, but only about 2 degrees. Link to comment Share on other sites More sharing options...
deezel Posted December 12, 2003 Report Share Posted December 12, 2003 I'm not sure, but I think the predator probably adjusts the timing across the whole RPM range. I'd be careful and look for knock retard if you try that... With LS1Edit you could change the timing just at idle rpms, but then you could raise the idle speed too... the 4 idle tables BigTex described. Link to comment Share on other sites More sharing options...
GMike Posted December 12, 2003 Author Report Share Posted December 12, 2003 Anyone in the Kansas City area have LS1edit and a willingness to see if modifying the idle table rpm's? It's worth a case of your favorite brew! Mike Lind [email protected] Link to comment Share on other sites More sharing options...
GMike Posted December 12, 2003 Author Report Share Posted 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 site 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. I can't think of any other way to fix and clean the throttle body. Any other suggestions? Possibly a new one? Anyone make a good replacement for a 2002 6.0L Escalade? Link to comment Share on other sites More sharing options...
marc_w Posted December 12, 2003 Report Share Posted December 12, 2003 Yeah, timing at idle, will effect idle quality... From there I can't help much. I don't know much about timing... Just going by past experience with my old car. My SS does this too. I can keep the truck in park, stab the throttle, watch the RPM's go up to like, 2500-3000... and then watch them drop to ~250, engine studders, lights dim, and then it catches back up to about 500 again. It'll occasionally drop to ~400 or so coming to a stop. If I'm turning, the power steering gets tight and the engine feels like it wants to stall. It's kind of hard to catch it off guard like this. It usually corrects within a second. Link to comment Share on other sites More sharing options...
BenKey Posted December 12, 2003 Report Share Posted December 12, 2003 Not a huge amount of moving parts in the TB. Remove and clean yourself with some carb cleaner. Then have the dealership fix your idle problem. Link to comment Share on other sites More sharing options...
BigTex Posted December 12, 2003 Report Share Posted December 12, 2003 Link to comment Share on other sites More sharing options...
GEAR M UP Posted December 12, 2003 Report Share Posted December 12, 2003 With the cold weather, (teens) I've noticed at low rpm's some lag or slow responce..... Once she warms up, were good to go! Link to comment Share on other sites More sharing options...
sliderbkt Posted December 13, 2003 Report Share Posted December 13, 2003 You may want to try to clean your MAF also. Pull it out of the intake and spray it with electrical parts cleaner and let it dry. That may help. Link to comment Share on other sites More sharing options...
Viperkiller97 Posted December 13, 2003 Report Share Posted December 13, 2003 Link to comment Share on other sites More sharing options...
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