Having trouble with a friend's Jimmy not starting intermittently. sometimes it starts right up, sometimes it does this where it starts up fine but it immediately shuts itself back off. it has a new fuel pump in it, not sure that it's had much else work done on it. another friend suggested the ignition module, or ignition coil, we tried switching those with no different results at all. I've seen some people say the theft system? could be causing this? not sure where to go from there, or if that's even where we should be starting. any help would be greatly appreciated, thank you

 

What is the security light doing during all of this?

George

 

I've been dealing with a very intermittant "Crank but does not Run" condition in my Blazer.

I posted the pages from my GM manual on how to troubleshoot it and others have given some really good advice too. You might look it up to get more ideas.

For my case, it it so rare that I haven't been able to figure it out.

https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/temporary-no-start-ignition-firing-1999-blazer-105792/