I have a 98 blazer 4.3L 4x4, she won't run. She will crank but won't start.
I have changed the starter- cap & rotor - spark plugs & wires - coil- ing mod.
Checked fuel pump & wires - crank sencor and all wires and relays under hood.
I put the obd 2 scanner on the other day and no codes
Now I put the scanner and it pops 2 codes. P0171 & P0174 which I checked and nothing wrong. I'm a chevy girl but this is getting crazy out of hand. I'm stuck and don't have any more clues. Please help!

 

Have you checked for spark at the coil tower while cranking? Must jump a half inch gap and produce a blue, not orange, spark to ground.

Have you checked fuel pressure and leakdown? This link explains: https://blazerforum.com/forum/2nd-ge...eakdown-88305/
Low fuel pressure can and will cause P0171 & P0174 to set simultaneously.

 

It was low fuel pressure, put gas in the TB and it started right up, now have to get a new fuel pump. Just replaced 1 1/2 ago.

 

Use genuine AC Delco or Delphi replacement pumps ONLY. Most aftermarket pumps have a lifetime guarantee, but what good is it if you have to replace it every year and a half? They have issues other than longevity too. OEM pumps are good for 100K miles.

 

Had similar problem with my 2000 Blazer. Installed Delphi fuel pump FG0072 from Rockauto and everything is fine now after 2 years.

 

I was told that fuel pumps do go often.

 

This is only true, if u don't use Ac Delco, or Delphi pumps on these trks!

 

Your a busy person

 

Haha