Originally Posted by CARGUY
can someone point me in the right direction on troubleshooting this . 1990 gmc suburban 5.7 tbi [wont start no fuel pump, no injectors]. it will start on starting fluid so i got spark. it blows ecm fuse when you turn the key on.
I have seen cars with no spark fire on starting fluid. If you want to verify spark you need to check to see if there is spark at the plug. Dont assume anything. Ether has a very low flash point and will fire without spark, just like a diesel does. I got fooled by this once myself.
As far as the fuse, it could be anything. You need to disconnect sensors and see if the fuse still blows. It could also be a bad ecm or a shorted wire. You just need to methodicaly eliminate things until you find it. If it is the ECM more than likely there is also something else wrong that shorted the ECM out. You need to OHM out all the sensors and anything else the ecm drives until you find the bad part.