1G Electrical - Bad Relay, No Spark

[tsibryan]

First off, this question isn't about my car. My dad bought a 1991 Talon TSi FWD last week, and we're trying to get it running. The car is all stock. When the key is in and I turn in to on, a relay near the center console shorts and buzzes constantly. When I try to start the car, it will turn over, but it won't fire. The fuel is getting there, but we don't have any spark. The battery is good and charged. I looked in a Haynes manual and didn't find the relay. I'm thinking maybe the ECU is bad and therefore we're not getting spark, but I don't want to swap in a good one until I figure out what this relay does. It looks like it plugs straight into the harness. Anyways, here are some picture of it:

http://s94997405.onlinehome.us/relay/mini-DSC04463.JPG

http://s94997405.onlinehome.us/relay/mini-DSC04468.JPG

http://s94997405.onlinehome.us/relay/mini-DSC04467.JPG

Also, are there some other reasons why there is no spark? Maybe something I missed? Thanks for any help

-Bryan

 

[beat90tsi]

I also think you should check the ECU before anything else.

 

[steve]

That's the MPI relay and you should pull the ECU and look for damage before wandering too far off course. The MPI relay gets power from the MPI fuse on the positive battery terminal. When the ECU sees the ignition switch turned to the RUN position it pulls the relay coil low causing it to switch power to pins 4 and 5 and power up rest of the ECU and half the stuff in the engine bay. If the MPI relay is buzzing that usually means a power short or low voltage through the relay coil.

Considering how common ECU damage is from leaking capacitors it's a good idea to pull it and have it checked out.

Steve

 

[tsibryan]

Thanks for the advice. I'll pull the ecu probably Friday and take a look at it. I'll be back with what I find out.