98 blazer 4x4 auto.


I have a problem with my truck starting. I checked the fuel pressure and it is 58 psi. with key foward, and 50-52 psi. running. But I haven't been able to drive it because it has left me stranded twice. I was wondering if a bad fuel pump or one thats about to quit will sometimes not turn on, and when it does run it has good pressure. Or do you think I have a problem in the wiring or a bad ground ?

 

You didn't really tell us much about the symptoms, but test the battery, starter, and verify good spark to all cylinders.

 

Test the fuel pressure when you are experiencing the no-start condition.

Do you notice any abnormal lights on the dash when you are having the trouble?

 

I have narrowed it down to the fuel pump. I can pour a little gas into the throttle body and it will start and run for 1-3 sec. then die. I had it running a couple days ago and the fuel pressure checked good. The fuel pump relay only clicks when the fuel pump decides to come on. I replaced relay, no fix. I am going to try and test the pump, any sugetions.

 

Jumper across the relay cavities. Look on the side of the relay for the schematic of the relay. You will be jumpering pins that are cross corners from each other on the relay. You will need to make up a jumper that fits into the cavities in the fuse/relay center.

If the pump still does not provide proper pressure, then there is either a defect in the wiring and/or ground to the pump or the pump itself is defective.

 

I pulled the tank today and noticed the black wire from plug on top of pump was not crimped tight. With just slight pressure i accidently pulled it out of its heatshrink -type butt connector. Do you think this would give random starting ? Also have a problem with anytime there is less than 3/8-1/4 tank of gas it will stall out when coming to a stop. It has done this every since i bought it a year ago. So i just run above 1/2 closer to full and have no problems. The pump is a "carter" brand-name its 1 year/ 1 month old, and has close to 40 k miles on it. Does anyone have expirence with this brand pump ? Is it possible it could be going out ? Or should i rewire the plug and try it again ?

 

I would rewire it first. A loose connection in the pump power feed can certainly cause some erratic operation. Low voltage will cause the pump to run hot if it runs at all which could explain why it performed worse at under 3/8 of a tank.