I had trouble stalling at idle.. it progressed quickly to sometimes bogging down at speed. When I get up to speed it seems ok, and sometimes it idles fine. Went to Autozone for codes and got codes P0171 and P0174 with printout recommending replace throttle position sensor, which my vehicle doesn't have. After some research, I (either wrongly or i got a bad throttle body) concluded that the diagnosis was accurate, and components of throttle position sensor were integral in valve body. So I replaced valve body, which did nothing.


Lots more research. Re ran codes at Advanced. This time I got P0171 and P0174 twice plus P0113 Then on the way home, prob cleared up, and codes cleared!!. They did not clear them at Advanced. But prob was back in morning.


I replaced intake air temp sensor(P0113) I checked for vacuum and manifold leaks. I removed and tested O2 sensors (ok) removed and cleaned (w/map cleaner) PCV and MAF (everything looked pretty clean, including old valve body). and tested fuel pressure(loaner from Autozone) I got steady fuel pressure at 20 psi, and i believe it should be at 49 psi. BTW i ordered an inexpensive OBDII scanner so i could see some live readings (confirm O2 sensors and fuel pressure ....anything else??). It should have been here, but tracking says I won't see it till Fri or Mon.


I feel a little above my pay grade. Any suggestions? I think fuel pump is failing; for me that is a big job. Just want to be sure. If it is failing, i understand, but at 20 psi steady (snapshot) I would think I could idle (I grew up on carbeuretors and no electronics). Also, if i need to replace pump, I've seen online that pulling bed back is easier than dropping tank (I'm working on grass or asphalt drive w 10 gal in tank). Either way its a project f me. Thoughts?

Thank you in advance for your help.

 

20 PSI is inadequate to the task. I suspect it's time for a new pump.

 

You need a new pump. You can pull the bed back as the bolts for the tank straps tend to break. I never replaced one on a truck but they do have a place on the fuel pump to siphon out the gas so it's empty

 

I agree with the pump needing replaced. 20 psi is way low. I would recommend dropping the tank. I would think pulling the bed off would be worse then dropping the tank. As for the 10 gallons in the tank. Unhook the fuel line at the fuel rail and drain it. If you dont have the release tool try some thick plastic jammed in the same way the tools work.

 

Thanks guys. Y it was pump. I deliberated, but decided to just tilt bed up (left in 2 back bolts 1/2 way) rather than drain tank and risk breaking rusty bolts. Also wanted to avoid draining tank and jacking up truck on my asphalt drive A little tight but not bad at all