I have a 97 blazer with 230,000 on it. After it cools down the only way it will start is by dumping a little gas in it. I have 53 lbs fuel pressure and replaced the cam and crank sensors. after it starts it runs great. Any thoughts, I'm baffelled

 

Fuel pump. Fuel pressure is way too low.

 

seems low but runs great after it starts. from what I read 55-60 to start. I've put 3 filters in it in 3 years, the last one was really dirty. pump is loud but was since I bought it. I'm gunna change the filter again, I did have the tank down once before this problem started. I dont wanna start throwin hundred dollar bills at it. I'll let u know and thanx.

 

It runs well after it starts because the voltage rises to 14.4V when the engine is running. It will just not run soon.

 

Have you tried checking the pump sock? If you are changing the inline filter that often I'd bet the sock is covered with a lot of larger stuff.

 

Fuel pressure should be between 60-65 PSI with the key on, engine off, and should hold above 55 PSI for at least 10 minutes after you turn off the key. Any lower than that and it will cause problems starting. Like Diaita said, once it's running the voltage to the pump goes from 12v (battery only) to 14v (alternator charging). That 2 volt jump is huge for electronics and they run way more efficiently.

 

ok drove it 4 a week with the gauge on it so i could keep checking it. below 51 lbs it wouldnt start, and fluctuated btw 53 and 60 running. i broke down and bought the pump today(ouch), but it runs great now. Thanx 4 the help.