1989 Full Size Blazer, Was running great and then as I was in a fast food drive thru line, It just shut off.. I tried to restart it but it just kept turning over? Had it towed home..UGGHH..
Have checked for both spark and fuel, You can hear fuel pump turn on when key is turned. Before checking for spark I also tried starting fluid and gas down the TBI..nothing..
I moved on to check for spark... No Spark at all... Pulled dist cap to check cap and rotor (both have less then 5k miles since change out last spring), all looked good. I have a spark tester tool that connects inline with the spark plug wire and spark plug...no spark.. I even tested my other car to make sure spark tester is working,,, Works fine on other car..
I even tried to get spark from dist cap to rotor...no spark/power.. I swapped out a coil from my daughters tahoe to my blazer..no spark anywhere....
I am at a loss as to where to go from here?? How do I check to see if there is power getting to the coil, and where is that power comming from so I can go and follow the power loss backwards?
I have checked all fuse's in the fuse box, all are good.. Have crawled under and checked wireing on starter and shook around at other wires, have checked connections under hood...ran my hand down most wires to firewall...
I am not sure where to look from here, any help would be Awesome as it is my only 4x4 and winter is here, just glad no snow expected this week..


It is a 1989 Chevy Silverado Full Size Blazer.. 5.7(350)..TBI..3.73 Gears...4" lift, pwr everything...

 

could possibly be a ignition switch. or wires coming out of it. i dont have a wiring diagram but i would try to find the 12v thats supposed to be going to the coil and see if thats working properly. if its not you can run your own source to it and see if the truck will start that will at least get you headed in the right direction.

i used to have a bunch of older chevys where the ignition modules would blow on them all the time, you can try replacing that. its that little half moon looking thing under the distributor that looks like this...



actually when i did my intake on my 1990 (same kind engine) it was pretty rusty and one of the screws holding it down was actually broke off. maybe that thing took a crap

 

I found on line how to test power to coil and ICM, had power to ICM, removed it and took it to Auto Zone. They were able to check it for me and it did come out bad... I had them even check the new one as to make sure they were testing properly before I paid $48 for the new one... Took and replaced with new one and WooHooo we have spark again... Thank you "abig84"..... Did you ever figure out what was causing yours to blow out?.. Is this something I may have to look foward to again?? Its up and running like a beast again.....

 

yeah after like the fourth time i finally figured it out and its nothing you should have to worry about with your style engine. on the old HEI style engines they put the coils on top of the distributors, anyways one of the wires was stripped open a bit and was arching to the ground and frying the ignition modules, i dont know how i didnt notice it right away.

glad you got it figured out. took me a while to know what went wrong the first time mine blew out also

 

I had a similar problem with my 89 K5 Blazer. Was riding down the road and it just died for no apparent reason. Would not start back but would crank. Turned out that there is a metal tube that the starter wires run through. It is intended to prevent the wires from getting against the exhaust manifold. The wires had rubbed against the edge of the tube and shorted out. As soon as I got the problem corrected, everything was back to normal.