1990 no start problem

Scanner would not comm with the ECM. No fuel out of injectors/ no pulse power to them.Well has power to one side but will not pulse. Replaced ECM has two chips in it. Still will not fire . Fuel pressure is good. Checked grounds seem good along with fuses. Where to next 1990 5.7 auto 2wd 1500
Jim

Your sure you have spark?

Your sure you have spark?

No spark

Did you swap the PROM chips from one ECM to the replacement ECM?

My next thought would be to look into the cam or crank sensors, as they provide the ECM with signals that it uses to command fuel pressure and spark. Does this truck even have crank and cam sensors?

Verify the ECM is receiving b+ 12v with key on.

Ignition module and pickup coil. At least check for power to the pickup coil but no spark and no injector pulse usually mean bad pickup coil. As long as the distributor is out the module is right there.

Ok so do I have to pull the disrib to change the pick up coil? How do I check it ? See if has power or ohm it?

You pickup coil plastic cover will most likely be cracked regardless if it still works or not.

Having been there, done that (I just sold my 90 after owning it for 20 years), it is more cost effective to replace the dist with a rebuilt that to replace the pickup coil and ignition module.

In order to replace the pickup coil, the dist needs to be pulled and the drive gear removed to replace the pickup coil.

//2000CAYukon

Ok so do I have to pull the disrib to change the pick up coil? How do I check it ? See if has power or ohm it?

You have to pull the distributor cap and rotor to change, not the whole distributor. Pull the ignition module and take it to your local auto parts store, they should be able to test it. The ignition mudule controls spark and injector signal. The pickup coil tells the ignition module when to send the signal. Hope this helps.

It was the Ing. Mod. Thanks for all the help. Jim