Questions and Answers

Dodge Neon Engine Swapped, Runs Bad Q. Dear Vincent Ciulla, I have a 1995 Dodge Neon, Highline, 2.0 liter SOHC, with similar problems that Lynn had. Previously, my car did not want to start and so had to get it towed to a nearby shop. After two days, they found that the problem was the ECM. They changed it and the car was fine.

One evening I was driving home from school and the car started shaking and did not want to accelerate anymore; I had to get it towed.

After a mechanic inspected the car, he found that the engine block had a hole the size of a fist. I don't know how this could have happened, but anyway I opted to swap the engine. They swapped the engine with a 1998 engine. Ever since, my car starts to jerk once reaching a speed of 50-55 mph. It also feels as if it hesitates once I try to accelerate while I'm on the expressway.

extreme consumption of gas. I have changed the fuel filter and I still continue to have the same problem. I hope it is not the transmission. Maybe I need a new ECM for a 1998 engine. Please help me.

Thanks,
Vincent

A. The basic engine and cylinder head is different from 1995 to 1998. So, naturally, the operating parameters are different. If they took off the intake from your old engine and put it on the new engine, it should be all right since the sensors and injectors are matched to the PCM.

If they used the intake from the replacement engine, you could run into problems with the sensors and injectors since they are matched to the 1998 PCM. In essence you have EFI parts from two different years. If you put a 1998 PCM in, you might run into a conflict with the Mass Air Flow sensor and Transmission controls. For example, the Throttle Position Sensors (TPS) and Crankshaft Position Sensors (CPS) are different between the two years.

Of course this is assuming the engine swap is the root of the problem. You should try pulling codes from the PCM to see what that gives you.

If you still have access to the old engine, you could try swapping the intakes and that should take care of any problems related to the engine swap.