1987 K5 problem...
 

I bought this truck last year. 2 days after my purchased the engine blew. so I replaced it with a 350 5.7L TBI. since I have had a problem with it missing while its running and at a idle. and dies with out any sign. it just shuts off. I have replaced all vacuum lines, distributor, all sensors, rebuilt the throttle body and it still is happening. only thing I think it could be is something is screwy in the harness. giving a real thought to switching to a 650 holley carb. I have gotten all my info for these boards so I figured y'all are the best to ask!

Re: 1987 K5 problem...
 

My painter had an 88 K5, same exact story except he did not replace the engine. He even swapped the throttle body with one I had that we knew was good. Sometimes he would go a week without issue, then it would just die for no reason. Almost always would restart within 2 minutes, but was annoying as all get out. We found a few wires that were broken inside the insulation, so I really think it's old brittle wires.

I bought it from him and am just waiting to get funds together. Gonna drop a new crate engine in it and yank the underhood harness and find someone to rebuild it and test it. Then I'll rebuild the steering column top to bottom and hope that fixes it.

Re: 1987 K5 problem...
 

that's what I am thinking! I bought this truck to slowly learn how to work on trucks. I am a 27 year veteran at holding the flash light. this truck has ben a crash course! but I have got down to the harness. thank you! I have no idea how the harness works or even where is at. the man who swapped my engine didn't do anything on it right. only had one motor mount pin in and no nuts on them. this truck has been put through hell but i'm working it back up. working on my lift and adding 35" 12.50 15" on it soon!

Re: 1987 K5 problem...
 

Ouch. The unmolested K5's are getting so hard to find. Getting one with a lift and big tires that's had a sawzall party are a dime a dozen. I beg you.... BEG YOU! :(

Re: 1987 K5 problem...
 

well this one was rode hard through clay and mud and left to rot away. the undercarriage is clay and mud stained. there was clay in my air filter housing. ever since I first saw a blazer I wanted it not big lift but a little to make it beefy. not for mudding or trails just I love that look of it. I want mine to look like the one in this picture. there will be no cutting or fender flaring or chopped. I want the k5 body un-touched.

Re: 1987 K5 problem...
 

Take a look at the coil plug in. It plugs in straight down. The wires are close to the air cleaner and I've had them break and wear right at the plug in. Same deal. No start. Take the air cleaner off and starts right up Super pain to track down

Re: 1987 K5 problem...
 

Could be an EGR issue. Check out this thread. Good info.

http://www.chevytalk.org/fusionbb/sh...php?tid/258416

Re: 1987 K5 problem...
 

Awesome! Thank you I'll check this one out!!!

Re: 1987 K5 problem...
 

Zthanks GMC guy! Wiring is what I'm thinking is causing it. This truck has sat for a long time before I got it. So I'm think old wire are cracked and shorting out.