QuestionI have a 1990 Grand Prix 3.1L v6 sedan. A few weeks ago while driving home the car started cutting out and when I pulled over the car ran fine. I got home and next day it still did it while driving. I did a tune up, replacing air, oil and fuel filters, changed plugs, wires and oil too. Now engine won't start unless I hold down the accelerator to the floor, and engine surges. If i let off the gas, it stalls. No engine trouble codes are present just 12. Fuel pump makes whiz noise when ignition is turned on. Whats the best way to test the egr and exhaust converter, or could it be bad fuel pump?
AnswerHI, check the fuel pressure, if the it's below 41psi with the key turned on, then it could be the fuel pump is weak, on the egr valve the diaphragm could be busted, by the engine not wanting to run, you would need a vacuum pump to it. the converter could be clogged, if it is clogged there would very little exhaust coming out of the tailpipe,
