I have a 2001 Saturn SWP which has the same engine as an SL1. The engine when out in it so I put in an engine from a 2002 Saturn SL1 (which ran fine in the car before I took it out). After the swap I installed the computer what came with the 2002 engine. When I turn the key over the car starts for about half a second then dies. Seems like it isnt getting enough gas so I pulled off the fuel line and turned the key and it seems to have plenty of fuel pressure. I decided to try putting the old engines computer in the car. With that computer the car starts then the rpms start rising fast like I'm holding the gas petal to the floor. So I have to kill the engine after only 2 seconds or it will hit redline. I'm not sure what the problem is, any input would be helpful. Thanks.

 

Keep the old computer, but take all the sensors off the old engine and put them on the new engine. Include especially the IAC and the TPS

 

Thanks that fixed the problem, my car is running now.