I do appologize if this has been covered, but i would like to get an idea. Im bing offered a 95 sr for cheap. The issue with the truck is lack of spark. I know of some possibilities but know theres more. Can you knowlegeable guys just throw ideas out there. Im trying to visualize the worst case scenario to see if this truck is worth buying. Thanks in advance!

Worst case, bad ecu. Next, bad power transistor trio. Next, all coils bad (only if total no spark, not just no spark to some cylinders). Next, bad crank/camshaft positions sensors (fairly common). These are about the only no spark causes except a bad connection somewhere.

Thanks fast eddy for your fast response. Your great answer is more than appreciated. So what kind of pocket damage would one be looking at for a bad ecu? Oh btw, truck died while running on the freeway if that helps you lean towards any particular scenario. Timing belt is on nice and tight and everything turns fine. I know the sound of a broken timing belt and its not that. Thanks again!

Rebuild here: http://avproecm.com/index.htm

I think mine was $168 few years back. You should be able to do a self test on the ECU to determine if bad.

i have a good ECU you can have for $65.00 shipped

Thanks, guys for the input and the offer! I will pull the tigger on this purchase and start troubleshooting soon after. I'll have that used ecu in mind in case thats my problem.

Thanks for the input, guys. I will purchase the truck and start troubleshooting soon after. I'll have that used ecu in mind in case i need it!

you can part it out, sell me the springs, locker, and air pump <img src="/forums/images/graemlins/smile.gif" alt="" />

I'm inclined to agree with fasteddy. I had a similar situation on my 1989 3.0L SOHC 12 Valve engine once. Also on a highway situation, its kind of a funny coincidence now that I think about it. It turns out that I didn't plug in the connector to the power transistor all the way and it came loose. After trying to restart it on the side of the highway a couple times, I popped the hood and it took me about 5 minutes of looking at different things before I spotted the connector had come loose (had not completely come off, that's why I didn't notice immediately).

I reconnected it and it started right up.

The power transistor can be seen in this image. It isn't labeled but can clearly be seen just below and to the left of the ignition coil. Small black rectangular block with the connector attached to it.

Jay, his setup is different. He has 3 coils firing 6 plugs using waste spark system. THe coils are triggerd by an assembly with 4 power transistors in it, three of which fire the coils and the 4th (IIRC) turns the power on to the PT's. I don't remember what it looks like off hand, or exactly where it is, but it's all in the 92-96 fsm...