I bought an 86 NA with engine fire damage (pd-got another one). I swapped in a 88NA engine with the harness from the donor car. The motor fired and ran for a few seconds x 2. Then it would not start or even appear to fire. I checked the spark, and was not getting anything. I trailered the car to a mechanic. He/we swapped in new igniters, new ecu, etc from running vehicles and could not get the engine to start. He has diagnosed the problem as incorrect voltage to the igniters.
He suspects that there is a short in the electrical system. The two options that I was given were 1) trace down the short in the existing wiring 2) put in a new harness ( I have one about half way out of a wrecking yard car,but lost interest when I got behind the dash).
The other weird thing is that the fuel pump runs when the key is on, and doesnt shut off. The car had a funky car alarm system, and I am wondering if that might be part of the electrical problem.
Any suggestions on how to proceed from here?

 

Wrong voltage to the ignitors??? what voltage is it??? what is he smoking???

I would be looking at the aftermarket alarm wiring first, but without knowing the specifics of the worng voltage it would be impossible to say what the problem really is...

But I would think he is smoking crack if he told me wrong voltage was the problem... its 12volts... its either there or not... how can it be wrong?

 

yeah, the whole thing probably hinges on the aftermarket car alarm. I havent seen the readings, but my understanding is that the igniters are only seeing 4.5 volts, unless i'm the one smoking crack and have not grasped what he is saying(yeah, it seems like 12 volts is 12 volts, but wtf do I know).

 

The LEAD coil assy get 12v on the B/Y wire coming from the Main Relay and a switched approx 4.5 from the ECU. That shouldn't be hard to figure out if you missing or have half *** voltage coming from the Main Relay. Just point to point with a meter or check the voltage coming and going from the Main Relay.

Common sense says to look at the part of the harness that was fire damaged and find out if any fuses are popping.

Just ring the wires from the coils from end to end and look for a dead short on each wire with both ends of the wire disconnected from whatever unit they go to.

 

thanks for the diagram, i will spend the weekend with the ohm meter. got sidetracked when the S10(parts chaser) lost the oil drain plug in the middle of the cascade mtns with no cell service in the middle of a rain storm, but what is life without a little fun!!!