Why would a 1991 Lumina with 250000 miles run like new but sometimes be very hard starting especially in cold weather?

Answer 1

Take the vehicle in for diagnosis and tuneup. Starting with tune up is a good idea if your planning on keeping the car. It may save diagnostic money. On the other hand if the problem is an expensive repair and you decide to dump the car, the tune up money is wasted. Check your records for the last tune up part replacement. You should have date and miliage. Are they due? If not, have the diagnosis done. Since this is a cold weather problem, I would be suspicious of a ignition module, coolant temp sensor or ignition coil pack problem (there are three of them). Pull the plugs and check condition, if two of the cylinder's plugs are black, see if they go to the same coil, that may lead you to a coil problem. I believe the older luminas (I assume we are talking the Lumina Car not the Lumina APV Van) have the coil and ignition module on the firewall side of the motor. The crank shaft sensor is a common problem on those. It is under the ignition module. Post you findings. It may have a problem starting especially in cold weather because you battery could be bad. Cold weather starting is hard on a battery. Just go have you battery and your alternator checked and most likely one of those is the problem. Had the same problem. The Chevy dealership had no clue what to do. Replace the spark plugs and coat plug ends (side where cable attaches with di-electric grease. Remove EGR valve from plenum. There is probably a ton of carbon deposit in the port hole (should be about one inch in diameter. Use a dremel tool to grind out the carbon and a shop vac to suck up the debris. You don't want the debris going into the plenum! Be sure to clean up the carbon on the EGR port hole as well. I'd replace the oxygen sensor too. Cheap fix - about $35. Re-assemble and your car will run like new again, the heater will blow hot air again, and your gas mileage will improve noteably.