Can anyone help with Ecm Prom ID
Question:
I just changed the engine in my 87 Chev 4×4, Now Its sluggish and I get a code 43. The scanner says to check for upgraded Prom ( amoung other things that test good) . A service book I checked showed by P/N that the ecm was the same for a 305 cid and a 350 cid but the proms were different , and it listed lots of prom numbers. The parts stores including GM say I need the numbers off the original prom I require . Can anyone tell me what prom number I would need for a 87 350 cid with TBI and a turbo 400 W/O lockup. Thanks Al
Response:
You’re sure the knock sensor, and the ESC module (if it has one) are connected properly? What is probably happening is that it is getting a continuous knock signal making it constantly retard the spark timing, which sets the trouble code, and also causes it to be sluggish because of the retarded timing. — Robert Hancock Saskatoon, SK, Canada Home Page: http://members.home.net/hancockr
– Hide quoted text — Show quoted text -> I just changed the engine in my 87 Chev 4×4, Now Its sluggish and I > get a code 43. The scanner says to check for upgraded Prom ( amoung > other things that test good) . A service book I checked showed by P/N > that the ecm was the same for a 305 cid and a 350 cid but the proms > were different , and it listed lots of prom numbers. The parts stores > including GM say I need the numbers off the original prom I require . > Can anyone tell me what prom number I would need for a 87 350 cid with > TBI and a turbo 400 W/O lockup. > Thanks > Al
Response:
What year model was your new motor? I ran into a problem similar to that. It seems the cams were different enough to confuse the ECM. After a little trial and error adjusting the timing, we got it almost right. Would still set off code 43 if you used premium fuel. RJ 1986 GMC Jimmy with a 1988 engine. – Hide quoted text — Show quoted text – >I just changed the engine in my 87 Chev 4×4, Now Its sluggish and I >get a code 43. The scanner says to check for upgraded Prom ( amoung >other things that test good) . A service book I checked showed by P/N >that the ecm was the same for a 305 cid and a 350 cid but the proms >were different , and it listed lots of prom numbers. The parts stores >including GM say I need the numbers off the original prom I require . >Can anyone tell me what prom number I would need for a 87 350 cid with >TBI and a turbo 400 W/O lockup. >Thanks >Al
Response:
Hi and thanks for replying. I had the truck on one of those snap-on scanners, If I tapped on the block beside the knock sennsor the scanner showed the timing was retarding , so the knock sensor works, I swapped out the esc module because I had a spare , it didn’t help. The new motor was out of a 91 cube van , The original 305 was I believe type H , and the new 350 is type K . I thought ok. the scanner says prom try it and carry on from there. I just don’t no exactly what prom I need. Al.
Response:
> Hi and thanks for replying. > I had the truck on one of those snap-on scanners, If I tapped on the > block beside the knock sennsor the scanner showed the timing was > retarding , so the knock sensor works, I swapped out the esc module > because I had a spare , it didn’t help. > The new motor was out of a 91 cube van , The original 305 was I > believe type H , and the new 350 is type K . > I thought ok. the scanner says prom try it and carry on from there. > I just don’t no exactly what prom I need. > Al.
It appears that you were using a Snap-On scanner with the trouble shooter cartridge, along with the trouble shooter cartridge there should have been a Prom Cross-reference book. Use the scanner to extract the prom code (data line prom ID), look it up under the model year and prom ID, it should give the replacement prom number. — Neil Nelson Send Lawyers Guns and Money, The shit has hit the fan. WZ It’s good to be back!
