I just recently ran into a problem with my voltage, and found out it was my battery not holding charge, and wouldn't start unless it was on the charger. I replaced the battery with an Optima D34/78 and the car starts like a champ. I thought maybe the 5000 rpm shifts may be related to the voltage problem I had, but alas, no. Anyways...
The problem I am having is that the transmission won't shift until at least 5000 rpm's. Regardless of throttle position, the car still won't shift until it hits exactly 5000. At WOT, it will shift at the normal 6100+. So, I have several guesses as to what might be the problem.
1. I may have bad grounds on the boost (lol), voltage, and oil pressure gauges I installed. I can check that tomorrow.
2. My dad's friend is a technician for many makes and models and he said that it could be due to the low vacuum from the cams and head. I believe HPtuners could fix this, although I don't feel like dropping that kind of cash unless absolutely necessary.
3. The stall speed may be too high...Highly doubt it though.
4. The car spits carbon out of my exhaust like crazy, so I know I need a wideband badly. This might affect the ecu thinking that the car is in WOT all the time... This is merely a BS guess..
5. TPS might be bad.
Any thoughts?
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"Youth in Asia"...I don't see anything wrong with that.
Ignore #1...The gauges wouldn't even work without a good ground.
Also, the fuses related to the trans have been checked, and are fine.
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"Youth in Asia"...I don't see anything wrong with that.
1. Your gauges won't affect your shift speed.
2. Your friend needs to review his information on the 4T40E (the auto tranny in your car). That particular transmission is not vacuum controlled, its electronic (hence the E at the end). No vac signals.
3. If you haven't changed the torque convertor, then no, its not too high.
4. The cars determination of WOT or not is made soley by the TPS, the O2 sensor is just a feedback device.
5. This is more possible than the rest. You need to get the car on the Tech-II to measure TPS position, or find somebody with HPT that can hook up to your car and check it out.
There are certain other things that can affect it:
1. Is your IAT sensor hooked up and working?
2. Do you have a CEL?
3. Does your TPS show 0-1% at idle?
4. Is your idle high?
5. Do you have all your sensors hooked up?
6. Is your VSS working?
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How ever, the PCM does use MAP voltage to correlate shift points along with TPS voltage. That said if the two don’t "add-up" it will throw a code.
But like Ron said, you have some digging to do.
Before you start throwing darts, spend some time diagnosing it. A TEC-II, OTC Geniuses, or any other "live" scan tool would be best.
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
I don't know how you do it Ron, but it seems that you are the first to answer most of my questions. I am throwing a code, so I just ordered a cheap DTC scan/ delete tool. I may just buy a new TPS anyways, since the TB is over 15 years old. When I ran the car before, the shifting was fine, but that was before I installed the TB and gauges. I think I will just try the other 2.3L TB I have with the modified 2.4L TPS just temporarily to see if it makes a difference. If so, then I know the culprit.
Thanks for the input guys.
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"Youth in Asia"...I don't see anything wrong with that.
^ yes you can, both are 5V to ground, myself and tom are using a LG0\LD2 TB
you have to get a multi meater, or a live scantool to do a "sweep" of the voltage. at idle, it sould be less than 1v, around .63-.25, and at WOT 4.95-5.00V
but id think a bad TPS OR MAP could cause this.
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
It was the TPS. Thanks again Chris and Ron.
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"Youth in Asia"...I don't see anything wrong with that.
Good to hear.
If any of us at Team Green can help, dont hesatate to ask.
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
