Wondering what ESC module and knock sensor i should be using with the EBL flash system. Car is a 89 firebird with a 350 and has the original ESC and KS. Reason i ask is some times the car runs fine and others has problems starting and runs like crap til i advance the distributor. Has new plugs wires and distributor. WUD has a knock count in the 400's but the SPK table doesnt show any knock counts at any rpm ranges. Any help would be appreciated...

Thanks
Bill

 

The ESC module and knock sensor will be no different then with a stock ECM. The ECM only retards timing when the knock detection system reports it. Which is done by pulling the ESC signal to the ECM low (pin B7).

During cranking any reported knock is ignored. The distributor will fire the plugs at the base timing setting. This is the same as if the EST/BYPASS connector is open (the ECM commands it open electrically).

Once the engine starts and the RPM exceeds 400 the ECM takes over timing duties (it electrically closes the EST/BYPASS).

The initial knock counts you are seeing are from the starter engaging. Makes a lot of noise. The WUD filters these out as it knows that the engine isn't running yet. Although at key-off knock can and is usually reported at some random point. This is from the ESC module being powered off before the ECM is.

As for the issue of starting and needing to advance the distributor. Once the engine is running do you then un-advance the distributor? It may be that the ignition module has a problem. Also, check the star wheel on the distributor shaft (below the rotor). Make sure that is hasn't come loose from the shaft.

RBob.