My 2001 Pontiac Sunfire hesitates, jerks on hot humid days. Worst when I accelerate and the A/C is on. Also the gas gage quit working. What could be wrong?
We have been to 3 mechanics.Replaced the gas cap, fuel pump, ignition cord,fuel filter, spark plugs w/wires and the problem still isn't fixed.
Is your "check engine" light on? If so, have the computer scanned and post the trouble code(s) here. That will be a big help. With the engine idling switch on the A/C. The engine should speed up a bit to compensate for the added load of the A/C compressor. If it doesn't that means the IAC (idle air control valve) isn't working correctly. Or the computer isn't getting the "A/C request signal" when the air conditioning is switched on. As for the gas gauge, check the wiring back by the tank. Sounds like a bad connection. This may be causing the engine problem too. You have a vent valve (electronic) that is incorporated in with the fuel pump module. As is the gas gauge sending unit. If this vent valve isn't working it can cause drivability problems and should cause your "check engine" light to come on as well. HTH. -Jim
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