So today i was driving home from work and i noticed i couldn't get upto speed to fast, and also a knocking from the engine was happening (Injectors) then when i pushed the pedal even more it started to Hiccup a bit, but when i let off the pedal, both noises stopped and i could go. so i stopped and then started again and then i had all power and was able to floor it and what not. Is that a fuel pump starting to die?

Matt

 

Depending on how old the fuel filter is that may be the problem.

 

i changed it about 4 months ago would it be time to change it again.

Matthew

 

I don't remember what the owner's manual says but it should be good for at least 30,000 miles unless the tank is rusting inside or if you have been getting dirty gas at uncle charlies el-cheapo gas station.

 

i have been working on these trucks for 8 years now and when a fuel pump dies, it dies for good. Exspecially GM fuel pumps!!! lol any who, you said you shut the truck off and started it back up just fine?? if your truck was sputtering, kicking, and hickuping and it was the fuel pump it deffenetly would not start up again. Also are you tossing any codes (SES light) that would be nice to know. There is a huge list of things it could be clogged fuel filter, massive intake gasket leak, a dead injector (unlikely) ect... you get the point but if i would have to say i put mass air flow sensors in these things left and right, try swapping one with one of ur friends that also have a blazer with the same engine code and see if it still does it. BUT dont quote me on this it can be a fuel pump, or any of the ubove i said. But normally if a pump is only off by 5p.s.i it will make your engine run like poop, but i have only see the p.s.i drop on the T.B.I engines, kuz they normally run like 8-10 and if they drop to 5-6 the truck goes no where. On the 93 and up blazers the fuel pump really does not drop pressure they normally just crap out, hope all this helps man and good luck

 

There is no one size fits all diagnosis. Yes a fuel pump can go bad and the vehicle will still start and run. Our 1996 had intermittent trouble where it might start fine or it might take 2-12 tries before it would start. Once started it always ran fine. This went on for many months. Fuel pressure was 53-55. The GM spec is 58 psi. One day it failed to start and the pressure was 33 psi. With a new pump it starts instantly every time now and runs fine. However the fuel pressure is now only 47 psi. In theory it should not start at 47 psi.

 

I have a 95 that ran like crap. It would start fine but would miss, and hesitate while driving. I checked the fuel pressure and it was at 55 psi - key on, engine off. I replaced the fuel pressure regulator and the pressure jumped up to 65 psi and it runs great.

 

Thanks for all the replies
I do not have any ses light on, i have not tried the MAF sensor i guess i could go buy one. WOuldn't i get a code on that? I have an abs light on for the last couple days. I have not had those symptoms since that day. since i got this blazer in back in may i have always a little problem when i am driving down the road. It will loose power for a 1/10 of a second then it will be right back. Its intermintent though some times its worse then others. Then that day were it didn't have any power and it was knocking was the first time ever. I have had problems starting it before but never over 2 times turning the key. Dunno pretty crazy.

matt

 

Hard to diagnose from here but it sounds like an ignition issue. A MAF problem can throw a code but not always. You can buy a spray can of MAF cleaner. A friend had a lack of power/hesitation issue and cleanng the MAF cleared it right up.