ECU swap

CHAZ1983

MEMBER
1997 PONTIAC SUNFIRE
120,000 MILES

Is the ecu in a 97 sunfire 2.2 just plug in an go or what do I have to do? I been trying to get my sunfire back on the road for over 6 months one day it stalled an only starts if pedal is to floor than it dies I change fuel pump ignition an coils crank idle tps señor an also I injectors with to success only way I learned to keep car runing is to take out fuel pump fuse an keep it running with starter fluid in the intake it runs perfect on starter fluid so my guess is that the computer must be flooding an stallin the engine I notice after Putin on thousands in parts that the computer is not secure I can reach up the passage side tire an grab computer an move it all around all plastic that houses the computer is broke or someone forgot to screw it back in anyway I think it's bad an trying to replace it do I need to flash the used ecu or change the prom chip or just plug it all up an start car thanks

1 Reply

CARADIODOC

MECHANIC
33,741 POSTS

At some point you have to realize the least expensive and fastest way to get this solved is by taking it to a mechanic; that is unless you're doing it for the challenge. The most expensive way to diagnose something like this is by throwing random parts at it. Each time you replace a sensor, the computer has to relearn its characteristic since no two sensors are ever exactly alike. There is a specific set of conditions that must occur for the computer to compare one new sensor's readings with other things it knows from other sensors. When you replace a second or third part that are used to learn the characteristics of the first one, the computer gets confused and there's no way the engine is going to run right, even if you accidentally replace the original defective part.

Have you even determined if the fuel pump is running and if you have fuel pressure? We know you have spark since it runs on starting fluid. As for a used computer, it may be able to be reflashed with updated software but it should not need to be programmed to your specific car at the dealership. GM didn't start that nonsense until 2002.