Letters: Intermittent stalling has Grand Prix owner worried

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Updated: November 15, 2011 11:43AM

Q: I own a 2004 Pontiac Grand Prix (56,000 miles). I don’t drive the car as much as I used to, and I’ve been experiencing an intermittent problem that has become frustrating to me.

Once in a while during initial startup the engine will stall. I’ll start it back up and it will begin to stall until I give it some gas. After giving it some gas it will stay running. Other than that, the car runs like a dream and the check engine light does not come on.

Recently I brought my car to my mechanic. I thought it might be a problem with the fuel injectors, fuel pump or fuel filter. He told me that the engine would be running poorly if it were the fuel injectors. He told me it wouldn’t start at all if it were the fuel pump. He also told me my car does not have a fuel filter. He said there’s nothing wrong with my car and that this is how a Grand Prix behaves.

I think this is a warning sign of something wrong. But he assures me that nothing is wrong with the car. Could it be bad gas? My husband agrees with the mechanic, saying there’s nothing wrong with the car. I would appreciate your opinion. – Janet, e-mail

A: I don’t agree that it’s normal. The engine should not stall out upon startup.

And your car does have a fuel filter. But I don’t believe it’s the source of your trouble. I also don’t believe your car has a case of bad gas. But since your car doesn’t get driven that much, it’s a potential candidate for carbon buildup on the back of the intake valves. You might want to purchase a fuel system additive that you can pour in the gas tank. Then take your car for a lengthy highway ride. This may help. If not, find a more capable repair facility.

Q: In one of your previous columns you mentioned a Carfax report. I’m wondering if you can tell me how to obtain it. – Della, Chicago

A: Visit to the following website: carfax.com/free_carfax_reports.cfx.

Q: I own a 1991 Honda Accord. The problem is that sometimes the shift interlock solenoid will not unlock the shifter when depressing the brake pedal. The brake switch and shift lock solenoid have been replaced but the problem remains. Also, when this malfunction occurs I sometimes get a flashing “sport” light on the instrument panel, which I believe may indicate a possible transmission control module problem. Sometimes the transmission doesn’t shift normally, and then it clears itself up after driving for a while. This problem has been baffling for me and many technicians. Do you have any idea as to what could be the problem? – Roy, Chicago

A: I would suggest checking the electrical connections at the transmission control unit. The brake switch is monitored by the control unit, and then the control unit provides an output signal to a separate interlock control unit, which ultimately provides the ground for the shift lock solenoid.

Since your car is also experiencing transmission performance issues, I would start with the transmission control unit’s connections as a possible source of trouble. Other than possible poor electrical connections, it could be that the transmission control unit is beginning to fail.

Questions for Ira Siegel? Call the Auto Advisor Hotline at (708) 633-6839 or e-mail ira.siegel.is@gmail.com. Siegel is an automotive instructor and an automotive service excellence-certified master auto technician.