I have a 1988 Chevy Blazer K5 350 with Fuel Injection and it runs great except, when I start it up cold and it starts just fine, runs a high idle and seems okay. When I take off it to drive it it runs normal but when I drive for a short time at a normal speed of 40 or so, then let off the gas to come to a stop light and coasting the motor just dies. I turn the key and it starts right up again. It does not happen all the time but it does on a semi regular basis. Anybody that can help thank you. If it was a carb engine I would know what was wrong but not so schooled on Fuel Injected motors. Thanks, Doug

 

Try putting in a bottle of Fuel injector cleaner

 

I'll try that! Thanks...Anybody got any other advice???

Thanks,
Doug

 

Check for a vacuum leak at the throttle body base gasket. I just spray a little carb or brake cleaner around the base of the throttle body while it's idling to check for vacuum leaks.

 

Vacuum leaks are evil! They're almost as bad as electrical gremlins! lol

But as Chevy said, check for vacuum leaks, my old Z34 did the same thing, until I got tired of it and changed out all the vacuum lines... Fixed the problem for me... Had I use the carb/brake/wd40 spray method, I probably could've done without replacing all of the lines... But I'm not known for thinking everything through, lol.

If that's not it, there's a slim chance your cat could be acting up... Very slim chance, though...

 

Thanks, I'll check that too.

Doug