Questions and Answers

Chevy S-10 Blazer Ignition Timing Q. Hello. I have a 1992 Chevy S-10 Blazer 4.3 liter fuel injected, automatic transmission, ABS brakes, PS, A/C, cruise with 130,000 miles. Truck will not start unless distributor is turned to advance spark. Once running, distributor can be turned back to 0° BTDC but truck begins to run rough, pop's and threatens backfire when it gets warm. Plugs pulled are black and fouled.

Parts already replaced are as follows: New spark plugs, wires, pick up coil, ignition coil, distributor module, distributor cap and rotor, throttle position sensor, water temperature sensor and a new computer.

Engine is in mechanical time and distributor is aligned with no. 1 cylinder. Compression check showed approximately 125 psi.

I am at the end of my rope. I know these engines run well. With all the new parts invested, what could be left? Any input you may have would be appreciated!

Many thanks,
Joel

A. Is the timing being set properly? Have you found and unplugged the bypass wire to set the base timing? Should be under the dash or in the engine wire harness somewhere.