My 91 Lumina Euro 3.1 dies randomly.. its scaring me, i have been driving my 73 Chevy Cheyenne C20 Camper special
(with a 454 Big block 4:6:3 gears 12 bolt posi) and the truck is nice and all... but i would like to get more than 7 miles per gallon....
Now the lumina does not have any codes, always checked fluids, refilled when needed, all those kinds of things. timing belt was replaced at 120k miles, car now has 144k, and its not the transmission my car has the TH-125 (3 speed no overdrive) Now for what its doing.
The car randomly dies when warmed up, or at least i think only when warmed up. Once she starts dieing, she will keep doing it if you start her back up. When she dies you can feel a rpm surge sometimes and then she just dies, othertimes i dont notice it like if im in park its a nice and quiet car.
When she dies you can turn the key and start her right back up, and she runs like normal. It died on me a few times, one time i was getting on the freeway on one of those loops that go from an overpass to get to the freeway which is going another direction. she died about halfway through since there was no throttle input.
the other time i was just sitting in the parking lot at 7-11 waiting for my friend to get out of the store, and i went to shift and pressed the gas and she was dead. started right back up though.
the third time i was driving back from a few cities over, i was doing 65 MPH and 3000 RPM all of a sudden i feel a big grab, like something locked up in the tires and i look down at the Tach and wathced the needle bounce fro 3000 right down to about 700 or so and right back up to 3000 and stopped, the car kept driving like normal. so i gave her some more gas sped up to about 80ish since if shes going to be doing this i want to be home or at least closer to it. i felt her give me another one but smaller, so i was about 20 exits from my place, about 5 miles. i let off the gas a little, and the entire way back i can feel these little rpm drops and hear them too, but it was random.
now i went around and checked all the fuses, they are fine. Altenator is new within a year its fine, battery is fine, car could use some new spark plug wires and plugs but that cant cause this, its not ignition related im sure of that.
My grandfather is a GM tech, he was thinking that it could be electrical if it happened that fast. My brother tells me he think its a Vacuum leak, and my neighbor who is a GM tech said it could be a Fuel pump. But if it was a fuel pump could it still make it run fine untill it warmed up?
Im leaning towards a Vacuum line, can anyone give me any insight on this. i really want to get her fixed by this weekend.
Thanks
-Jeff