ive had this happen twice to me so far. Once two weeks ago and just a few hours ago when i was pulling up to my house. The car will just all of a sudden, out of the blue, loose power and start stumbling and the ses light will come on. When i shut it down and start the car back up its fine again. The codes i got where for the esc module (42) and knock esc (43)/ I hooked my laptop up to it and saw that it was populating the knock counts in the cell located at 400 rpm and 100 MAP like crazy. When i looked at it it had around 273 counts there. Another three or four randomly placed cells had one or two counts. This is kind of funny because my engine comes no where near idling at 400 rpm. Normally around 600 in gear and dropped to around 550 during this incedent. I have a new borg-warner 350 knock sensor that i got with my new engine so i dont think its that. Should i just replace the esc module and wait and see or is it possibly something else?

 

>i dont think this was it... The code 42 was probably an old code and i probably forgot to reset the ecm when i tiimed the engine.

 

in the service manual it says
The system performs a functional check once per startup to check the ESC system. To perform this check, the ECM will advance the spark when the coolant is above 194 F and at high lo-ad condition (near WOT). The ECM then checks the signal on CKT 485 (Spark retard signal) to see if knock was destected...If the function check fails (no knock), the SES light will remain "ON" untill the ign. is turned off or knock is detected

This sounds an awful lot like what happend to me. Both of the times that this happened, the engine was under load and the coolant was warm. Shutting the engine down killed the SES light and stored the code 43. I remember retarding my timing to help the engine cope with my 305 injectors (now 350 injjectors) so if the timing was retarded along with the fact that the engine has 8.5:1 CR no knock may have resulted during the test setting the code 43. Does this sound plausible to anyone?

 

The computer will adjust for the advance only so much... If you have it too far advanced, you will experience a lot of ping and SES problems.
I have the feeling the computer is trying very hard to compensate for your advance. You might want to back off the timing a few degrees and reset the computer. Give it some time to adjust. It may take about 2 weeks for the computer to get a feel for your new setting.
Or take it to some place that has the correct diagnostic equipment and find out exactly what is happening if that fails.

 

my timing is RETARDED... i set it to about 2-3 btdc because the old injectors will go lean otherwise. This engine doesnt seem to knock for a damn. Even when i did my ring seat in procedure i only got two or three knock counts on my laptop and thats on 8 month old stale gas. I guess ill set it to the stock 6 deg btdc setting and see what happens. If the ecm performs the check and gets no knock i imagine it would throw the code. If it starts knocking more and promptly throws the code then ill definatly know its not the sensor, module, or bad connection but excessive knock.

 

well... looks like it was a little more retarded then i thought. Like 8 deg after top dead center. That alone would be enough to set a code. Simultaniously fixed my hard start and low vacuum too!

 

fixed... i guess its good that i left all the stupid careless mistakes untill after the engine install. Never knew a v8 was supposed to run good like that. all teh preveous v8's my bro had and my old clapped out 305 ran like crap.