2000 Blazer - Hard starting, but runs fine after starting
 

have a 2000 Blazer (4.3, LT) that,a couple weeks ago, began to have issues starting. The scenario is this: If it sets for a couple hours, you hit the ignition, and you may have to hit it 4 or 5 times, some times it will almost catch, then sputter and die. After the 4-5-6 time, it will start fine, and run fine until it's shut off and left to set for a couple hours.

If you turn the switch to On, and wait about 3-5 seconds, then turn it to start, it starts right up, every time.

Some times when the switch is turned on, the radio, or the dash lights, or the electric seat control don't come on, but the next time or two, it comes on fine, and whatever was out, works fine until the next time.

Background:
The vehicle has about 145,000 on it.
Replaced the fuel pump with an aftermarket pump about 30k back
replaced the plugs and wires about 25k back
Do regular oil changes every 3K
Replaced the catalytic converter about 40K back
Had the tranny rebuilt about 50K back
There are no codes stored in the computer, and the service engine light isn't on.

Thoughts? Suggestions?

I have a suspicion about the ignition switch. Jerry

mine does the same thing but more in the afternoon time like around 2 or 3 when its hot.. somebody told me i had a weak fuel pump?

It could be a weak fuel pump, you might test it and see.

is there any way i could test it myself?

Do a fuel pressure leak down. There should be a test port on the engine and you rent or buy a simple fuel pressure gauge from the local autopart store.

ya i got it tested they said th pump was bad an had no pressure but i got a friend that has a fuel pressure tester an we tested it an it was 60 an 55 when running but i dident do the pressure leak down ant it if it leaks in 10 min. to 0 its the pump?

How did you test it when running? The pump tends to show going bad if you test it while driving and there is excessive pressure drop while accelerating hard. When I had a pump in my car go bad it would drop from 60 psi to 20 psi when flooring the car. The leak down would tell you there is an issue. It could be a bad pressure regulator, stuck injector or a variety of things causing the pressure to blead off. I think I read where pressure drop should be like 2 psi every 10 minutes or something like that.

If you turn the switch to On, and wait about 3-5 seconds, then turn it to start, it starts right up, every time.

It might be the checkvalve (non-serviceable, in the pump assembly). If so, just live with it and wait a brief moment between ignition-on and cranking the starter. I learned this habit a while back...:icon_shrug:

Better to look for leaking components in the intake plenum than throw a fuel pump at it. Either a leaking fuel pressure regulator or injector-related issue (cracked hose). A weekend project at best.

Shops always like to tell you the fuel pump is the problem because it's easy money for them if you choose to have it replaced. Your car won't start at all if it has no pressure.

i checked it running an reved it an i read that if u have a bad or leaking pressure regulator it will reduce fuel mileage...? i bought 1 but ant had the time 2 put it on.. my buddy told me it could be the injectors bc when i put sea foam through it it stoped doing for bout a mounth or 2 now its getin hard 2 start when hot weather again..