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Old 06-28-2007, 09:08 AM   #1
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Default PCM conundrum

So the saga continues - a month ago I sent back the ZZP PCM I had just purchased because the shift points from 1st to 2nd was 5500 rpm where it was supposed to be programmed at 6k. Plus, the car was performing worse with the new zzp PCM and 1.95 rocker install than before. When zzp shipped back my reprogrammed pcm a 2nd time, it seemed the car was running better and the shift points did go up to about 5,850. Last night was the first chance I got to test at the track. Earlier in the day, the car was still shifting around 5,800 or so. I thought for sure I'd get some decent runs in. Turns out, on every run and even driving afterwards, the car is now shifting at 5,500 again no matter what I do? Now I'm thinking To make matters worse, the car seems to get off the line ok, but then in the top of first gear and in second gear, it just seems to dawdle along. I'm certain the pcm is the culprit unless anyone knows of what may cause the sudden change in shift points?
I can e-mail zzp, but even if they agree to reprogram, I don't want the down time again on my car and have already given them two chances to get this right. Plus even after I installed the 1.95 rockers and the pcm, the car ran slower than it did before the two changes by a couple tenths. When I dropped pulley sizes by a tenth, it got me back to where I was before all the changes. Does anyone know a reputable programmer within 100 miles of Chicago that can program the pcm correctly and stand by their work?
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Old 06-28-2007, 09:25 AM   #2
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First off...Do you have any KR or scans that you can share for us to look for any oddites?

IIRC shifting is dicatated by either RPM or speed in the programming. It shifts based upon whichever parameter is met first.
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Old 06-28-2007, 09:25 AM   #3
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i know there is a strong GP following on ILCGP.com and a new forum and one of the members here TommyGloves creates, windycitypontiacs.org. im sure that you will find somebody that has a programmer
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Old 06-28-2007, 10:51 AM   #4
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Quote:
Originally Posted by BillBoost37
First off...Do you have any KR or scans that you can share for us to look for any oddites?

IIRC shifting is dicatated by either RPM or speed in the programming. It shifts based upon whichever parameter is met first.
Bill, I did not scan last night, but I scanned a couple times while driving before last night and everything seems to come out ok. Had an occasional 1-2 degrees of KR, but that was it - that still should not affect the shift point though? By the way, what is IIRC?
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Old 06-28-2007, 12:57 PM   #5
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IIRC - if I recall correctly?? Not sure

I was looking at your list of mods. Do you have headers on that thing? Did you go straight from stockers to 1.95s? What kind of scanner are you scanning with? How did the car perform before the installs?
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Old 06-28-2007, 02:40 PM   #6
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Quote:
Originally Posted by jshelton54
IIRC - if I recall correctly?? Not sure

I was looking at your list of mods. Do you have headers on that thing? Did you go straight from stockers to 1.95s? What kind of scanner are you scanning with? How did the car perform before the installs?
No headers right now - I might consider them in the future, but I think I need to sort out the programming issue first. Two things lead me to believe that it is the PCM and not the exhaust killing the car at the moment: One is the sudden change in shift points when I started pushing the car harder off the line than usual since I was at the track (lots of VHT). Second is that the car, running just a 3.5 pulley, after zzp adjusted the original programming error, ran consistently slower, especially throughout second gear - I lost about 2 mph and almost 2 tenths in the quarter. When I asked zzp what they did, they said they adjusted the timing. That helped the bottom end in first gear (had 2.07 60ft time), but now having problems top of 1st gear and all through second. I thought I heard some other members also mention they were running rockers w/o headers and did not have any issues.
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Old 06-28-2007, 04:25 PM   #7
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The only things to my knowledge that would change shifting should be the rpm or speed.

Didn't you say that when you first got the pcm back it shifted at the higher rpm?

I could understand that with the hot weather lately..that you might feel some lag from the car...
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Old 06-28-2007, 04:29 PM   #8
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Mechnically, all I can say is make sure you have no vacuum leaks anywhere (causing leanness), and do a full-sweep voltage test on your TPS sensor (could be that the TPS is acting up and you're never really going into WOT as far as the PCM knows).

As for what the PCM is doing/commanding, we can't even begin to accurately speculate on that unless you can get a scan logged and posted.

Another question...has everything you've described been done on the same set of wheels/tires?
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Old 06-28-2007, 11:20 PM   #9
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We are not within 100 miles, but we can ship to Chicago in a day Nobody on the planet does Bonneville PCM'* better than us. Nobody tunes as many 3800 cars on the dyno as we do and nobody makes more power with a series II/III 3800 than we do, period.
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Old 06-29-2007, 12:46 AM   #10
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amen brother.
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