I was looking at a friends 1994 Saturn with 127K miles on it. A couple days ago he was on the highway and it stalled once he pulled off. It started and ran like crap but he got it home.

I was looking at it and he had fuel and spark and a computer code for a MAP sensor. I checked the compression since the mileage and oil consumption issue. I got 80 100 80 and 100. It seemed very low so i thought the engine was done since the spec is near 200. (I thought bad rings) Well he brought it to a shop and they replaced the MAP and EGR valve. I didn’t think a bad MAP would cause a car to not start or even try to start. It would just crank over. It sounded like a no compression issue so I told him the motor was shot.

I did a complete tune up about 4500 miles ago and the plugs were already very dirty. Anyone have any experience with Saturn’s or any idea on why a the car wouldn’t start with these two bad parts. I know the car would run like absolute crap but no start at all? Any ideas?

 

Saturn uses MAP Manifold Absolute Pressure to determine air fuel requirements. Faulty MAP = no start. EGR valve not closing properly will allow exhaust gasses to enter the combustion chamber resulting in less air being available to produce proper combustion.

Regards

Jean Marc Chartier