Guys I need some help here. I got a 95 mustang with no spark... I've tested and replaced a few components. Let me start from the begining. Its a 95 mustang it originally was a v6 automatic car has been swapped to a v8. The harness was bought from a 95. The engine harness, mass air harness, and computer are all from the same car. The tfi module and distributor were from another car but have been tested and I even tried new replacements.I've done all the no start no spark tests and I'm not getting the signal to fire the coil. If I ground out the side of the coil I can make it fire. Also the injectors are not pulsing and the fuel pump does not prime. The rest of the sensors show the reference voltage. The injectors show the bat voltage on the one side and the other side shows 8.3 volts?? I don't understand that. I've tested that the ignition module, coil, and distributor they all have voltage. Now the weird thing when I hook up the scan tool it will not communicate but when I turn the ignition on the scan tool completely shuts off (it is hooked directly to the battery). The injectors do not preprime either. The transmission harness is not in the car. I have the nuetral safety switch bypassed. The processor is a t4mo. I'm almost certain I have had one of these year cars run with out the trans harness. I've done it a few times in newer ones for sure. I've tested at the spout connector and it does not flash when cranked. I've probed, poked, prodded and prayed and so far nothing.

 

is the injector harness grounded? also is the ecu grounded?

 

The ecu is for sure. Where would be the injector harness ground?

 

iirc it should come of the drivers side of the injector harness i believe, think it usually goes to the firewall

 

did you hook up the ground wire that goes from the engine to the frame?

 

Yes grounds are all hooked up. Keep em coming guys.

 

On 94-95 cars there is a problem with the hall effect switch in the distributor IIRC. I had a 94 GT that had a lot of the same symptoms. I replaced the distributor with a rebuilt one and it ran. There can be 12v going to to the distributor and it still won't run. It's a common problem on those cars.

 

Try this and report back - take off the A/C clutch connector. put a wire in the connector (harness side) and the other end of the wire ground it out to the frame. Do not have the a/c on while you do this. And see if you get any thing, if you do then you have a ground issue. I did this on my brothers 94 and everything came to life. I found out by probing it with a volt meter.

 

personally I would start by tracing why the fuel pump is not priming, start with the easy stuff and move step by step