I have a 95 GMC safari van 2wd 4.3 v6 auto with 145,000 miles. When I drove over 120 miles or so the van would not idle when I stopped it would even die. Gradually the van started running bad all the time. I have replaced the spark plugs, rotor, cap, air temp sensor, coolant temp sensor, oxygen sensor, removed the catalatyc converter then I replaced the EGR valve. The check engine light told me to replace the EGR valve. After replacing the valve the engine won't idle and runs bad. I removed the new valve and checked to see if it was plugged and it was not. The check engine light gave the code to replace the valve again. I check the voltage on the wires and that is correct. It acts like the valve stays open all the time. I searched for a blown fuse and could not find any but I might not have found all the fuses I need to check.
Couldn't have said it better myself. '95, 148k, meticulously maintained. The last 9 months have seen new fuel pump, 3 fuel filters, air filter, IAT valve, IAC valve, coolant temp. Sensor, vacuum lines, and Berryman's B-12 thru the fuel system. Finally gave up and took it in for a full diagnostic at the f@*$ ing dealershp -- they found nothing wrong at all. Still, the warmer it gets and/or the longer it runs, the worse the stumbling idle and lower the oil pressure gauge reads. Only thing I've heard that I haven't tried is a possible plugged oil pickup screen. Sounds like a lot of fun to fix and, running full synthetic changed every 3k with filter, I don't know how likely that sounds. Damn.
Am going to drop the $70 on O2 sensor today and am prepared to be underwhelmed. Will post if any miracles happen.
August, 16, 2007 AT 9:08 AM
Cap, wires, plugs, rotor, gas cap all recently replaced, too.