Code 43 problem

[GNERGY]

I pulled a code 43 today after finally getting the burb done and driving it around. It runs good but I noticed if I get on it at around 3500rpms it starts to pop so I got off of it. Tried it again from a rolling start and it would pop at 3500r's again. I can rev it to 4500 in park wuth no problem.
Is code 43 the knock sensor or the ESC module.
Need Ideas, Thanks
Tarey

 

[GNERGY]

So far I don't have any voltage going to the knock sensor, should be about 4.7 volts. Trying to find pinout for my 91 ECM to check for continuitity on the knock sensor at the ECM plug.
Any body got a an ECM pinout diagram.
Tarey

 

[eagle mark]

ftp://ftp.diy-efi.org/pub/gmecm/manuals/1227747/747ecm1.jpg

 

[eagle mark]

Code 43. Low voltage at electronic spark timing circuit

Don't rule out the EST in the distributor

 

[Thunder]

IIRC you should not have voltage going to the knock sensor. The KS is a piezoelectric crystal that generates voltage when the engine knocks. The voltage generated by the crystal is picked up by the ESC module and timing is retarded.
If your engine is poping at higher RPM. The noise will be picked up by the KS. the ESC wil retard timing. If it still is getting noise after timing is retarded it will set a code 43.
Your problem may mot be KS or ESC related.
The poping/misfireing may be caused by a bad spark plug wires, Cap rotor, distributor module, or pick up coil.
A lean Air fuel condition. ( this will usually set a code 44 also.)
Incorrect timing.
Worn timing chain.

 

[GNERGY]

So far I found I don't have 12v ( ign. ) going to the ESC module.
I have new timing chain and gears, wires, plugs, cap, rotor. timing set to 0 with wire disconnected. Fuel pressure set at 14.5 lbs. TBI chip.
Tarey

 

[dyeager535]

http://coloradok5.com/forums/showthread.php?t=141717&highlight=troubleshooting

Code 43 for TBI is there. Wiring should be very similar or same.

 

[GNERGY]

I found the pink/black stripe wire broken at one of the splices in the wiring harness that runs along the top back of the motor. It powered both the EGR and the ESC.
Thanks for the help guys.
Tarey