Hey guys, new around this place but Im a member on several other forums so I do know about the search function. Ive read many many threads here so far including the great sticky at the top of the section page but Im still scratching my head. Im desperately trying to find out why my wifes blazer will not start intermittently. The problem began about 2 weeks ago when It died on her in a burger king drive through and I had it towed home. It cranks over fine but will not fire. Things ive checked/replaced are as follows: Fuel pressure is at 52-55 PSI with the key on, pump kicks on every time I cycle the key, Security light is not flashing, it has spark at coil and at plugs (replaced cap and rotor), fuel filter is new, checked injector pulses with noid light, checked and cleaned crank sensor (covered in oil), replaced battery and it is not storing any codes. Now when this happened the first time after screwing around all day with it it finally fired up and ran ok untill yesterday when it died in the garage here at home. After I replaced the battery (it wasnt testing good) it started up and ran good again until this afternoon when my wife went to leave work. Im at a loss as to what to look at next, some people are saying fuel pump but Im not convinced that is the issue, maybe Im just being hopeful? Anyways, sorry for the long post, hopefully the chevy gods can shed some light on this for me. Thanks in advance!

 

Have you checked your alternator it might be going bad I had a problem like this with a 1998 chevy camaro with a 3800 series II v6 and it would start and run but once the battery was drained it would die again. You ca test it by starting it up then DISCONECT the battery and see if the alternator can run the car. Im NOT an expert but it sounds like the problem I had so it might be worth looking into.

 

Your IP cluster doesnt have a voltmeter?

I find mine pretty darn accurate.

Please dont disconnect the battery to see if you have a bad alternator.

95% of the time nothing bad will happen. But on the other hand you might have a bad alternator.

55lbs? Tad low. How is the leakdown?

The harness FP connector {2x2 design} is a known issue. Mine failed because of it. Perfectly good working pump but old.

Car harness connector bad inside. Hit road construction bump, BRava died 200 yards down road

 

Load tested alternator and it tested out good, forgot to add that to the checked list. Thanks though.

According to the book 55 PSI falls within the normal range with the key on/ engine off but Ive read conflicting info about what the proper PSI range should be. Im not sure what the leakdown should be but if I leave the gauge on fitting for a while and come back it drops down to about 20 PSI or so IIRC but as soon as I key the ignition it comes back up of course.

 

 

This ^^^

 

55psi is a tad low depending on the accuracy of your gauge. And the fact that it bleeds off means you have a leak. Book spec is key-on/engine-off pressure needs to be >60psi. 10 minutes after the pump shuts off, the pressure should still be >55psi. Sure sounds like a weak pump to me.

 

I had similar sounding problem with my 97. No fire sometimes and then would fire and run ok and then just shut off. Had a mechanic check it out and he traced it to some sort of module/switch(don't remember exactly what he called it) that was located in the steering column. He replaced it and never had another problem. Might be something to look at on yours.

 

Ive tried 2 different gauges and they both read the same. I was hoping it wasnt the fuel pump but it looks like that may be the issue, its been sitting in my dads shop for 2 weeks now and we cannot track down the problem. Its so strange, you can try to start it and get nothing but then other times it fires right up and runs great. So frustrating not being able to find a solid cause.

Did it have anything to do with the security system by chance?

 

Ok guys, an update and a plea for help. My blazer has been out of commission now for a couple weeks and still having issues but I've found a pattern, if I try to start it normally it will still only turn over but won't start BUT if I put a battery charger on the battery it fires right up. Now, the alternator was tested again and it failed so it is new, battery is new and charged, plugs and wires are new, cap and rotor is new, fuel filter is new. I can not figure out why it will start and run with a battery booster but not without it. Charging system is in perfect working order. I'm officially stumped!