Hey guys, my Blazer will crank but won't start. I don't have a fuel test guage but I pushed the detent on the test port and fuel shot onto the firewall. I pushed the detent again and fuel just dribbled out. I put the key in ACC for a few minutes and pushed the detent on the test port again and it still just dribbles out. I don't hear the pump at all either. The fuse is good. Anything else I can do to troubleshoot? Sounds like a fuel pump to me, I just want some second opinions before I tear this tank apart.

 

I don't believe that the pump runs with the key in the ACC position.

You really need to get a hold of a gauge to assess the pressure. Just watching how far it shoots up in the air doesn't tell you much given the specific pressure requirements of these engines.

BTW, please put your vehicle information in there somewhere.

 

You're right, I had the key in the "ON" position, not ACC. After cranking it a few times, the pump should have built up some pressure either way. It's a 96 4.3 4dr 4x4, I was pretty sure the fuel system didnt change much over the 2nd gen.

 

No the fuel system didn't change all that much from '96 thru the end of production, but you wouldn't believe how many people post the in the wrong forum.

As I said, you really need to get a gauge on it. Being able to tell the difference between 50psi & 55psi by pushing on the test port valve with a screw driver and watching it shot out is near impossible, but it is the difference between enough pressure to properly support engine operation & not.

 

Well, it runs again. It was the fuel pump. After dropping the tank I read the circuit and it was good. $149 for a new Bosch pump and about 5 hours of work put me back on the road.

I agree with you, a test guage would be an invaluable tool but since it went from enough pressure to spray in a steady streem to nothing, it was pretty obvious the gauge would have told me there was no pressure. Short of finding an extremely clogged filter or a mouse in the line, I was going into the tank either way, hahaha.