blown99 Posted March 22, 2014 Share Posted March 22, 2014 I have this 02 mustang gt, manual trans, that my customer just purchased. Complaint is very low power. I took it for a ride, no codes, no noises, mechanically it is all there. Found the ecm to pull timing, almost immediatly to 14 degrees once the engine comes up to about 3600rpm. Lugging the engine will drop the timing to 6 degrees. Car can not pull a hill on the highway in 5th gear. After looking over the car, I suspected an aftermarket calibration in the ecm. 14 degrees is the magic number for supercharged 4.6l 2v. The car has no cats and no check engine light, I did not see MIL eliminators on it. My job here is to get the power back and install cats, make it legal etc. I used IDS to do an ecm update, got a prompt that said ecm was at the latest cal. Went and hit program as replace ecm, appeared to program it. Took it for a ride with the same results. I happened to have a different MAF off a 99 lightning. I plugged that into it and the car ran 80% better. Reinstalled the original maf (reman maf btw) and ran the maf test in IDS, keeps failing that test. Customer wanted me to stop at that point and decided he would replace the MAF. Well, that did not fix his issue (told him my test maf would have a different curve to it) Does programming the ECM with IDS rewrite over the aftermarket calibrations? How do I use IDS to see if my rear o2's are still on? being monitored - monitor screen shows incomplete Found the ecm has been out of the car, has magic marker on it that says 4900. No signs of a chip being in it. Couple bolts on the intake were loose, aftermarket crank pully, rear gears have been changed and a bunch of suspension work. It is clear that someone played with this car and I still suspect aftermarket tuning, is there a specific procedure needed to reflash? Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted March 22, 2014 Share Posted March 22, 2014 If you reprogrammed the PCM with IDS it overwrote whatever was in it. Use DATA LOGGER to look at parameters Quote Link to comment Share on other sites More sharing options...
Aaron Posted March 22, 2014 Share Posted March 22, 2014 You will likely need to blank path program the PCM. Sometimes doing a PMI doesn't work. Hotline can give you the rundown on how to do it. It basically involves trying to identify the car with the key off until IDS prompts you to enter the tear tag (which can be found either on the PCM or on oasis by double clicking the vin in the top left corner of the screen) Once you have the session identified then perform your PMI, leaving the key off until after it says "install a new module in vehicle". Key the car on when prompted and it will blank path the module. After that you will need an active internet connection as the IDS will then download and configure asbuilt data for the PCM. You will likely also be prompted to enter the vin during this process as well. Hope this helps. Quote Link to comment Share on other sites More sharing options...
blown99 Posted March 25, 2014 Author Share Posted March 25, 2014 I spent sometime today with this car. I don't believe I can call hotline as I am now an indy. I attempted to program again but am not sure it actually blanked the module. I had a superchips programmer kicking around, I used that to adjust the axle ratio and am running that on justt the fuel economy tune (at least the speedo is not reading 120+ anymore) Found the fuel pressure to be in the low 30's under load. Dropped the tank. Found the svt focus pump in there, basket installed backwards and just sitting unclipped. Had a lot of dirt in the screens. Replaced the pump with a stock unit, cleaned the tank, repalced the filter and assembled it correctly. Still have the same low power issue, timing is pulled to 14-12 degrees once load is brought up to 60% or so. Tested the egr valve, OK no leaks, ran the maf and tp test ok. Noticed that when I am hitting bumps on the highway or have a stretch to run the engine out, it will surge and gain power (plugged fuel filter type feeling) but only when stretching the gears up around 5k rpm. Load at idle will be at 11% at times, this should be 20% correct? Cracked timing disc? this has an aftermarket crank pully. Timing is pretty solid at idle though. Suggestions? Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted March 25, 2014 Share Posted March 25, 2014 How are you checking fuel pressure? Are you using the fuel rail pressure pid? I would double check that rail pressure pid against a mechanical gage, they should be within 10 pi of each other. Quick and easy just to rule that out. However it would appear that spark advance is the low power issue on this unit, just not sure why its so retarded. Quote Link to comment Share on other sites More sharing options...
DieselD Posted March 25, 2014 Share Posted March 25, 2014 being it is a mustang it is quite possible you have a aftermarket performance PCM or even a factory one sent out to be modified. Does it have the typical PCM partnumbers, tear tags etc? You mentioned it has a 4900 written on it with a sharpie which isnt typical of a OEM pcm. Its possible I would think if its not a factory pcm or one that is internally modified the IDS isnt able to over write it. You say a couple intake bolts where loose and your timing looks to be setup for a supercharger. Sounds like the previous owner yanked off the supercharger before selling it and left the rest of the car alone. That would support the idea of a non ford pcm being used as well and could explain all your odd readings Quote Link to comment Share on other sites More sharing options...
Aaron Posted March 25, 2014 Share Posted March 25, 2014 Waaaaitaminnit.... Don't these pcm's use a piggyback chip on them to modify tuning? Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted March 25, 2014 Share Posted March 25, 2014 Waaaaitaminnit.... Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted March 26, 2014 Share Posted March 26, 2014 First Mustang PCM I ever flashed was in a 99 cobra for the power improvement recall. Used the WDS back in them days. We also flashed the brain boxes to correct the speedo after gear swaps. So I guess it could go both ways, but I think piggy backs were the way of the dinasour by then. Quote Link to comment Share on other sites More sharing options...
blown99 Posted April 2, 2014 Author Share Posted April 2, 2014 These ecms can be flashed with a programmer such as an SCT brand device or piggybacked out the J3 port with a chip. I did find the problem. Found the timing disc on the crank shaft was loose. The hub was hucked out along the key way area allowing the disc to retard and advance timing. Root cause was the crank damper bolt was only finger tight. I removed the crank sensor and was able to look through the hole in the front cover. Using a pick, I was able to see the timing disc flop back and forth. Pulled the cover, replaced the disc. Flashed the ecm. Car ran like it should. 1 Quote Link to comment Share on other sites More sharing options...
Steve Mutter Posted April 2, 2014 Share Posted April 2, 2014 Wow ! nice find, I bet your happy this one is done. Quote Link to comment Share on other sites More sharing options...
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