Driving me crazy

[anglerandy]

Going to make this as short as possible. 1988 Chevy 5.7 L T.B.I.. New short block with new heads that have better air flow thru intake ports. New plugs, cap, rotor, pick-up coil, ign. module, E.S.C., I.A.C., knock sensor, O-2 sensor, air pump. Base timing at 0'. No vac leaks. Valves adjusted. Fuel P.S.I. good. Dist. bushings good. Wire from knock sensor good. 9 volts to pin B7 on E.C.M..
Still getting code 43 after closed loop and W.O.T.
Also dead spot in acceleration just off idle( sometimes even a back-fire). What am I missing?

Andy

[anglerandy]

What? No super tech's on this site?

[2000CAYukon]

Look at Post #3 in this thread http://www.automotiveforums.com/vbul...d.php?t=954001

//2000CAYukon

[2000CAYukon]

Missed the part about a dead spot off idle. Are you sure the EGR solenoid is hooked up right? Stock cam?

Do you have access to a scan tool to see what the sensors are showing? The backfire could mean you are running lean.

//2000CAYukon

[anglerandy]

Mine is the old vintage with the external E.S.C.. It sends 9.2-9.3 volts to the E.C.M. It is not sensing a knock during the second "Test" that the E.C.U. does and then setting a code 43. I can get it to sense the knock sensor when the timing is advanced so I know that the circuit is good. All other sensors with in range.
When I run the engine on a scanner and run it on the "10k" test which advances the timing as part of the settings, it runs like a race car.

[sak22]

Not sure if you've resolved this yet, but you set the base timing at 0'... did you re-connect the spark advance?