So I am asking about my moms car that has everyone, shops included, boggled. She has a 2000 blazer LT with 130,000 miles on it that gets the routine maintenance done. Her car will drive like normal but sometime it will just die while she is driving it. Sometimes she can get it started, other times not so lucky. She will go shopping and come out and it wont start. Battery has been replace, alternator check out good, had her fuel lines flushed, and when it wont start and it is towed to the shop when ever they get around to look at it it starts so they say they can't detect anything. Oh another thing she has noticed it that her clock will reset itself sometimes before it starts acting up, along with her gas gauge has a slight 'float' to it. My husband thinks it could be the computer, she thinks it could be a throttle body like the shop 'thinks' it might be, and from what I read it could be the ignition switch. So we are all dumbfounded so to speak as to what to do next. She has to drive 30 miles back and forth to work everyday and I am a stay at home mom with one car that my husband takes to work, so it is getting a hard to find a car to borrow to rescue her when she breaks down. Any help will be greatly appreciated!

Thank you in advance,
Sara

 

Search around in Lighting & Electrical - Blazer Forum - Chevy Blazer Forums
& particularily https://blazerforum.com/forum/2nd-ge...roblems-73201/.
Try searches for starting issues, dies randomly etc. I'm pretty sure you'll find a few ideas as to the culprit. Like when mine did that it would shut of instantly. A small wire in a loom coming from the under hood fuse box would cause the BCM comp to pop it's fuse effectively - VERY effectively shutting the engine off.
Also the under hood fuse box etc as I mentioned in the last link I posted.
It all "sounds" electrical but has the fuel pump ever been replaced, with what brand & was a fuel pressure leak down test done? <---- You can search for that in here as well.

 

When you say it doesn't start does it even crank or does it just not do anything?

 

Thanks Rottidog I will do those searches shortly, as for the fuel pump the shop said it was fine but I don't think it has ever been replaced. I will also inform her about the test.

Mrspeedy69, Yes it cranks over and tries to start but with no success, like it is out of gas when its not.

 

You can easily test for spark by removing a spark plug & hooking it back up to the plug wire & placing the end electrode against the block & have someone turn it over. You should see a spark. If you do then it's fuel related, if you don't it's electrical. Something to go on, post the results.
Another even easier way is to remove the intake air temp sensor (little plug in the air intake plastic between the mass air flow & throttle body) get a can of brake cleaner, have someone try to start it while spraying brake cleaner into the hole from the IAT. If the can came with a tube then insert it so it faces the throttle body. If it fires & runs for a second it's fuel related & the spark is good.