2001 2wd Blazer. Would take a while to start sometimes after sitting (seemed like after it was rainy bur I live in FL and it rains a lot) Then last week it started stalling sometimes. Would run absolutely fine and then just lose power, wouldnt stall out right away, the tach would drop and it would poof poof poof kinda sound like it was missing badly and then quit. When trying to start it back up, sometimes it would do the same thing like it was missing really badly and then catch and run fine again. Sometimes it would just crank right back up or take a few moments of turning over to start. Didn't seem to matter the operating temp, had it stall when leaving the driveway, and once after driving it for 20 minutes. Then it stalled out yesterday, the same way, lost power, tach dropped, and seemed to be missing horribly.. and now wont start. It turns over but doesn't try to start. I know it could be a lot of things, but without checking it from top to bottom (and buying all the equipment to do the checking) is there a good place to start based on the symptoms? The thing I don't get is how it would run perfectly, then get to sputtering like hell before it stalled, then upon cranking it would run perfectly again... albeit sometimes take a bit to get it started. Any input would be greatly appreciated. And yes I've read a lot of threads before posting, but couldn't find any that sounded like they were having the same exact problem.

 

Are there any codes? How long has it been since a full tune up? May also want to do a fuel pressure and leakdown test

 

It's been too long since a full tune up, but what of a full tune up is going to cause it to run absolutely fine, and then just stall like that? It would at least run even if a plug wasnt firing at all. or it wouldnt run perfectly and then stall out like that. Also with a fuel leak down, what would I be looking at as possibilities that would work fine and then not at all then fine again before not working. Sure, I could run a total diagnostic rundown on it, but that would entail buying equipment that I do not currently have. I was kind of wondering if anyone had suggestions as to what it might be that would cause it to do what I described in the first post so I would at least know what I was looking for.

 

Sounds like its probably your fuel pump going bad! Like 50 said do a fuel pressure and leakdown test on it to start. Sometimes you just have to suck it up and buy a few new tools to figure these things out that's just the way of it. I believe some parts stores will rent you a fuel pressure tester. As for how to do the test just search around and you will find countless posts on how to do it and what is considered acceptable.

 

as for the codes, well I tried to start it until it killed the battery because sometimes i would take quite a long time to get it started. It is possible that the fuel pump I put in 4 months ago is going bad I suppose. Though I had a hard time starting it after it sat for a couple days both before and after I replaced the fuel pump. It was easy to know it was the fuel pump before... it quit buzzing when I turned the key on. I cant even check for spark because I dont have anyone available to turn the key for me.. haha. Well thanks for the advice. I had planned to buy a fuel pressure gauge and go from there, but I really dont think its the fuel pump and I wasnt sure how to figure out if it might be a FPR or even a spider assembly if it turned out to be fuel related, or exactly how to figure out if it's fuel related. Guess I'll wait until the battery is charged (on a charger now, start with checking for spark from the coil and work back that way, then progress to checking to see if it is fuel related.

 

What kind of pump did you put in it? The only way to really know if its fuel related is with a pressure tester. If it reads to low you know you have a bad pump or a leak somewhere.