Help with Hesitation and Engine Cutting Out
12-08-2005, 09:16 PM
#1
!! UNCONFIRMED EMAIL !!
Posts like a Northstar
Thread Starter
Join Date: Nov 2004
Posts: 584
Likes: 0
Received 0 Likes
on
0 Posts
Help with Hesitation and Engine Cutting Out
Well, my car started to give me some headaches. The car is a 1995 SSEi. It started with a slight miss and continued until the car will cut out completely and die. The engine check light has shown a P1640 Code - QDM for a while. The car had the fuel filter, O2 sensor, plugs, and wires replaced earlier this year.
So, this week I replaced the idle speed control motor, cleaned the EGR and TB, replaced the coils and ignition control with a low mileage 1998 unit and also replaced the ECM with a 1995 version and swapped the PROM. Installed a new TPS, when I started the car, it ran at 2500 for a bit and then it settled down. However, when I took the car for a drive it would not shift into OD and would start to miss and die when it did.
Used the digital voltmeter to check the voltage range and when I hooked the probes, the readings are negative or minus voltage!!! So, I checked the voltmeter on the battery and I get normal readings. So, I put back the old TPS and the car will not accelerate and to start, I have to step on the throttle like a carburated car! Put the volt meter and again the readings are minus. So, I hooked up the scanner and now I got a P0123 Code - TPS circuit high circuit input.
What am I missing here??? I replaced the TPS connector since the previous owner appears they broke it and used RTV to keep it in place. I know I believe I matched the wires correctly to the new harness. Any ideas or help??? Why am I getting minus voltage on my meter???
Thanks!!! I will appreciate any help; need the car this weekend urgently.
So, this week I replaced the idle speed control motor, cleaned the EGR and TB, replaced the coils and ignition control with a low mileage 1998 unit and also replaced the ECM with a 1995 version and swapped the PROM. Installed a new TPS, when I started the car, it ran at 2500 for a bit and then it settled down. However, when I took the car for a drive it would not shift into OD and would start to miss and die when it did.
Used the digital voltmeter to check the voltage range and when I hooked the probes, the readings are negative or minus voltage!!! So, I checked the voltmeter on the battery and I get normal readings. So, I put back the old TPS and the car will not accelerate and to start, I have to step on the throttle like a carburated car! Put the volt meter and again the readings are minus. So, I hooked up the scanner and now I got a P0123 Code - TPS circuit high circuit input.
What am I missing here??? I replaced the TPS connector since the previous owner appears they broke it and used RTV to keep it in place. I know I believe I matched the wires correctly to the new harness. Any ideas or help??? Why am I getting minus voltage on my meter???
Thanks!!! I will appreciate any help; need the car this weekend urgently.
12-09-2005, 06:27 PM
#2
!! UNCONFIRMED EMAIL !!
Posts like a Northstar
Thread Starter
Join Date: Nov 2004
Posts: 584
Likes: 0
Received 0 Likes
on
0 Posts
Well, found part one of the major problems and it is my own fault!! 
When swapping the ECM'*, I reinstalled again the original unit, but with the PROM from a VIN K engine application. Big difference when I installed the replacement ECM with the correct PROM; the P1640 Code - QDM code dissapeared. However, still have the P0123 code and the car will not shift to OD, which it is a symptom for this particular code. I am going to replace the TPS with a diffferent unit to see if I have a defective TPS. If there is thing else I should be looking for??? Any suggestions appreciated.
When swapping the ECM'*, I reinstalled again the original unit, but with the PROM from a VIN K engine application. Big difference when I installed the replacement ECM with the correct PROM; the P1640 Code - QDM code dissapeared. However, still have the P0123 code and the car will not shift to OD, which it is a symptom for this particular code. I am going to replace the TPS with a diffferent unit to see if I have a defective TPS. If there is thing else I should be looking for??? Any suggestions appreciated.
Thread
Thread Starter
Forum
Replies
Last Post
Toronto94Bonneville
1992-1999
2
08-22-2007 03:28 PM
natescovel
General GM Chat
5
05-16-2003 05:09 AM