My (dumb) electical saga

[BigAl]

1987 TBI 305.

I was doing some roofing one day and I saw a coolant puddle under the front of the truck. traced it to the radiator...

I replaced the radiator with a used one. The one I got had lost its' overflow nipple. I was able to rescue the nipple from the old rad. and attach it using some JB weld.

During old rad removal, one transmission line had rusted to the old rad. So I learned how to do a double flare with transmission oil flowing out if the pipe!

Satisfied with my repair, I went to hook up the battery. The Previous owner used a wired with a red stripe on the neg. side and I innadvertantly hooked up the battery backwards. Lot's of sparks and a smoking alternator....

I replaced the alternator, found a burnt fuse (ecmb). An there was no start. It would turn over but not catch. But it would catch with starting fluid.

I figured the problem was a reoocuring one I had with the fuel switching valve. It sometimes would get stuck on the tank that I don't use. I ripped out the old valve and wired the working pump directly to the electrics and the lines directly to the engine...also changed the old fuel filter (eewww!).

Still same no start condition.

Started changind ignition related items. Ignition control module (under disributor cap, all fusable links and still no joy...

Investigated TB and had to reinstall new gaskets for the fuel injectors...


More later!

[silvereagle07]

You may have fried the ECM for the engine. Usually modules are the first to go when hooking a battery up backwards.

[BigAl]

Sorry It was time to commute to work....

Originally Posted by silvereagle07

You may have fried the ECM for the engine. Usually modules are the first to go when hooking a battery up backwards.

I'll get to that...

The problem was that there was fuel in the TB but the injectors were'nt firing.

I finally got a computer from a junkyard and had some success.

Problem was an EXTREMELY high idle. It sounded like someone had floored the accelerator.

I did some research and found that this could be caused by a leaky TB gasket. Since I had also changed the Ignition control module, I figured that could be the problem. While the TB was out it was much easier to work near the distributor cap!

After the gaskets were in place, TB rebuilt, and the old Ignition control module was installed Everything worked!

I wish I had gone after the ECM first. But it gave me the chance to get intimate with the fuel and ignition systems of my truck.

the interesting thing is this. I would hav figured that the two chips on the computer would have been fied as well... But I am currently running with the old chips in the new computer...go figure!

So that's the end of the story. I figured I'd just add it to the knowledge base in case anybody else crosses their terminals like me!

[old Rusty C10]

thanks for the info!