A friend has a 1995LHS 3.5L with 150K miles. Symptoms are high idle (about
1200 RPM) and intermittent engine problems. He also gets a 41 diagnostic code. I'm not sure if they are all related or not as I have not actually seen the vehicle and am trying to help him via the phone. He says he has been trying to find the source of the problem for about 9 months now but has not been successful. When the engine acts up, he says there is no pattern. It can be at low speed or on the highway cruising at high end. He says that it has never left him stranded and always seems to get better after a few minutes, sometimes by pumping the accelerator and just driving through the poor performance period.What he has told me he has replaced thus far over the last few months are the gas filter, fuel injectors, fuel regulator and fuel pump. He tells me that he has also fixed an intake manifold leak as well and replaced several dry/cracked vacuum hoses. He says all the hoses are on and none are leaking since I thought this might have explained the high idle.
Does anyone have any ideas on what could make the engine intermittently run like cr**? He says it reminds him of a fuel delivery problem, but this is not likely given that almost everything has been replaced. He has asked for ideas and I suggested looking at his EGR since he was not sure if it had ever been replaced. I told him I would post the symptoms here to see if anyone else had encountered this previously and had a thought. Thanks in advance for your ideas and comments.
Bob