hello im mike this is my first post but been looking on here awhile i have a 2000 blazer lt 4 door.my problem is i had change the fuel pump now it takes to long to fire up.(cranks to long) but it has alot of power when i drive it.i put on a cold air intake also cleaned the maf senser.i was reading about it on here about different things colud be the problem.im gonna have a pressure check done them go from there.i read on here about maybe thre coil? but it dont miss on anything no check engine light on anything like that.ill try to post some pics of my blazer.

 

You need to do a fuel pressure test to check that your fuel pump is holding proper pressure, and that there's no leaks in your fuel system. It's possible that the fuel pump you got is bad, especially if you went with an off-brand like Airtex. There's a great diagnosis walk-through in the technical section.

 

Yeah start with the pressure test like El said and go from there. Did you change your inline filter when you did your pump? That may be a bit clogged as well. A good tune up can't hurt anything either!

 

+1 to both previous posts. Rent a fuel pressure gauge and hook it to the schrader valve on the fuel rail. Run the test with the key on, engine off! Your initial number should be between 60 and 65 and not go below 55 for 10 minutes. Post back your initial and 10 minute later numbers.

 

i replaced the filter also did a tune up.but i did take notice a fuel odor but not all the time.

 

Once you do the pressure test, it will tell more. I've had the same issue before and it ended up being the ICM. Another time it was a bad fuel pump.....thanks to AIRTEX, such a crappy brand. One other thing to make sure of though. When you replaced the fuel pump, you have to make sure you checked the electrical connector for the fuel pump. Mine was melted just enough to intermittenly cause me problems. Wouldn't hurt to check it out, but check your pressure first.

 

also some times when i drive it like going down a hill stepping on the brakes i can see the tach move down to zero then go back up and go back to zero sometimes not all the way to zero i can see it move these codes that yous are talking about can i see these without the check engine light on?thanks,mike