Had a guy I'm trying to help. Converted an LG4 305 car to SD TPI with a 7730 ecm. Car idles ok, revs up strong, but under load runs like crap. We also can't shake a code 43 that keeps popping up. "Faulty Electronic Spark Control". Memcal is new, and works good in another car.

He's still using the LG4 knock sensor and I think its freaking the ECM out and forcing limp home, hence the poor performance. Any thoughts guys?

 

I converted to a SD system too and kept getting 43. It just went away after a while for no reason. I do know that you must get a Knock Sensor for the 350 inch engine. When you say runs bad at WOT, do you mean flat, it won't accelerate or what?

 

Its a 305. We just put the tuned port on top of the existing 305ci engine. So I'll need to convince this guy to swap over to the 305 SD knock sensor. He doesn't want to spend anymore. LOL

Well, it revs up fine in park, but man, once you get it out on the street, its a dog. No ***** at all. Like it dead. Won't accelerate at all.

 

the resistance is diferent between the two sensors, my car did the same things and a 43, use a 90 up sensor and the code will go away