Quick question about an ECU in a 91 na convertable.

What will the car do if the ECU is bad? Will it even crank? fire? etc. etc. Any information will be helpful. A mechanic is working on my car and says the ECU is bad, and i have now gotten two of them off this sight, which i dont really believe both are bad, and he says they are.

Basically when i turn the key the starter moves, and i believe the solenoid is engaging, but the car does not start. He checked the ignition coils and the fuel pump and the starter, and those are fine, but the car still does not crank.

Can anyone give some information? ANYTHING would be helpful!

Thanks in a advance!

 

Do you mean the engine is turning but does not start ?

See if the spark plugs are soaking in fuel,
then it's flooded

If the spark plugs are dry,
check if there's fuel coming to the main fuel delivery pipe (or just check if you can hear the fuel pump)

Check if you have spark at the plugs

That's a good starting point, I think

Hugues -

 

You can have a bad ECU and the car will crank.

You need to find out if the sparkplugs are firing or not.

If the sparkplugs are firing, then the ECU is most likely good and the problem lies elsewhere.

Pull the lower plugs and lay the wires on the fender. Spin the engine. Did the wires spark to ground?

There are two things that will keep the coils from working. The forty amp fuse in the engine bay and the fuse in the cockpit called ENGINE. Either of these will keep the coils from firing.

If you discover that there is no spark, and the fuses are in place.......then go to your boost/pressure sensor and put a meter on the brown wire with a red stripe. With the key to ON, the wire should have 4 to 5 volts on it. If that is not the case.......the ECU is probably junk.

Check all those fuses in the engine bay while your there. Don't worry too much about the 80 amp fuse since the car cranks, so it must be good,.

 

Thanks Guys, im going to fax this info the that guy, and hopefully he will make some headway. i have not had my car for 2 weeks!!

Anyone in the Myrtle Beach SC area? want to make some $$$ fixing my car? lol