Engine ran just fine when taken out two months ago.

Just put the engine back in. Has spark, CEL comes on when the key is on and engine is off. Injectors have 12 volts, and if you ground them manually they spray a lot of fuel. Brand new ignition control module.

If you put 12v to the Purple/white wire coming off the distributor it will cause the injectors to spray, but plugged into the distributor spark happens and the injectors do nothing.

There is a tach lead from the coil itself. I attempted to run a paperclip from the tach lead to the Purple/White. Truck started but wouldnt idle.

Im at my witts end. How can the new ignition module not be sending the reference signal either? Where else could the issue even be?

 

Check and clean bottom surface of the ICM. Make sure that distributor mounting flange is also clean. Do not use too much thermal compound (white or clear looking compound) when installing ICM into dizzy. It's common to find 'new' ICM defective. A good used GM unit should do job in a stock application. Lastly, check all grounds, distributor clamp.

//RF