I have a 92 305 tbi. A while back I replaced the ECM because the injectors weren't pulsing (they were flooding my engine causing a no start). And after I replaced it the car ran okay, recently I've discovered my timing chain was loose so I replaced the gears ,chain etc. I've once again lost the injector pulse so now the ecm is flooding the engine . Could my timing chain have caused this issue with the ecm? The SECOND ecm started flooding my engine right before I changed the timing chain. Anyone have any experience with this? This will be my 3rd ECM if I replace this one.

 

It is rare for an ECM to just turn on the injectors. On TBI usually one or both of the wires get pinched under the air cleaner, which if it is the wire from the ECM will run one of the injectors full on.

A bad distributor or ICM or pickup coil could possibly cause the same thing. If it is sending reference pulses (DRP) to the ECM, the ECM will pulse the injectors. The ECM will pulse the injectors even if the distributor shouldn't be sending DRPs.

RBob.

 

Amen to the pinched wires. Always had to be careful of that w my Xfire.

 

Are you guys talking about the 4 wires that go from the ecm to the injectors??

 

Yes, at the TBI unit. I've seen many a car or truck in the JY with one or more of those wires pinched from the air cleaner. Have also nearly done this myself.

A 2-bbl TBI will have 4 wires, while a Xfire setup with two 1-bbl TBI's have two wires per TBI unit.

RBob.

 

I'm going to check on these wires today and make sure they're not pinched anywhere near the TB. I have already ordered an ecm so it's on its way. If it was a pinched wire or something like that, a new ECM wouldn't fix it .. am I correct? Oh and I forgot to mention one thing . The dizzy has been 180°off for Idk how long.

 

No wires are pinched near the throttle body for the injectors. Any other input on this issue?