91 3.1 Hesitation and stalling issues
dtabbs
11-20-2005, 03:20 PM
OK, I am new to this forum but maybe someone can help me out. I have been searching through the previous posts, and found that a lot of people have had some similar problems, but have not found a solution, or post saying “Hey I found it”.
91 Camaro RS 3.1L V6 MPI VIN T
150,000 miles
Recent tune up – plugs, wires, cap, rotor, fuel filter, air filter, oil and filter
This car has been running very well, but has recently just started having an issue. It will hesitate under acceleration, but not all of the time. When this happens there is a possibility that the car will completely stall out, but if you work the throttle a little you can keep it running. If you put the accelerator all the way to the floor it will sputter and backfire through the intake. At times the car will also stall out coming to a stop, and when this happens, you can smell that it has come to a lean burn condition. Once this happens the car does not want to start back up right away and may have to set 15 to 30 min.
From first explanation from the owner of what was happening with the car, I thought that the ignition module had gone bad, so I replaced this but did not have any effect on the issue. Next I thought that the issue may be fuel related, so I connected a fuel pressure gauge and test drove the vehicle. Checking the gauge when the car was failing I was still getting a steady 40psi, so the fuel pump and filter are not the cause of the problem.
While test driving the car for a while I found the problem to usually happen under acceleration and thought that the TPS may be the cause of the issue. I changed out the TPS and tried to check the diagnostic codes, only to find out that someone had removed the bulb and socket from the “Service Engine Soon” light. So I went to pulling the dash apart to correct this issue. After correcting the bulb issue I checked the diagnostic codes and only pulled 12 and 43. I changed out the TPS anyway, but this still did not solve the problem.
Code 43 is an issue with the knock sensor, but I know that this will not keep a car from running, as all that can happen is to retard the timing, which may cause acceleration to not be as good. I know that the catalyst is not the issue as the car when running correctly still has plenty of power, and will burn up the tires (yeah right it’s a 3.1 auto).
I have read in several posts that people feel that the injectors may cause a problem such as this, but being an MPI with six separate injectors, the odds of them all intermittently failing at the same time is not likely at all (better luck winning the lottery).
Any other thoughts or comments on this would be greatly appreciated.
91 Camaro RS 3.1L V6 MPI VIN T
150,000 miles
Recent tune up – plugs, wires, cap, rotor, fuel filter, air filter, oil and filter
This car has been running very well, but has recently just started having an issue. It will hesitate under acceleration, but not all of the time. When this happens there is a possibility that the car will completely stall out, but if you work the throttle a little you can keep it running. If you put the accelerator all the way to the floor it will sputter and backfire through the intake. At times the car will also stall out coming to a stop, and when this happens, you can smell that it has come to a lean burn condition. Once this happens the car does not want to start back up right away and may have to set 15 to 30 min.
From first explanation from the owner of what was happening with the car, I thought that the ignition module had gone bad, so I replaced this but did not have any effect on the issue. Next I thought that the issue may be fuel related, so I connected a fuel pressure gauge and test drove the vehicle. Checking the gauge when the car was failing I was still getting a steady 40psi, so the fuel pump and filter are not the cause of the problem.
While test driving the car for a while I found the problem to usually happen under acceleration and thought that the TPS may be the cause of the issue. I changed out the TPS and tried to check the diagnostic codes, only to find out that someone had removed the bulb and socket from the “Service Engine Soon” light. So I went to pulling the dash apart to correct this issue. After correcting the bulb issue I checked the diagnostic codes and only pulled 12 and 43. I changed out the TPS anyway, but this still did not solve the problem.
Code 43 is an issue with the knock sensor, but I know that this will not keep a car from running, as all that can happen is to retard the timing, which may cause acceleration to not be as good. I know that the catalyst is not the issue as the car when running correctly still has plenty of power, and will burn up the tires (yeah right it’s a 3.1 auto).
I have read in several posts that people feel that the injectors may cause a problem such as this, but being an MPI with six separate injectors, the odds of them all intermittently failing at the same time is not likely at all (better luck winning the lottery).
Any other thoughts or comments on this would be greatly appreciated.
wrightz28
11-21-2005, 05:04 PM
There are trouble shooting charts on 43 available in over the counter, chilton and haynes manuals. I believe there's also a link off Thridgen.org.
Automotive Network, Inc., Copyright ©2026