Im new to the forum and could really use some help. I've had an autometer analog fuel pressure gauge installed for a while now and last weekend i was hauling a pretty heavy load of rock and the fuel pressure gauge started to jump from 40-65 so rapidly the needle looked like a blur and then the truck started to idle and run really rough. I came back and took the cap off of the engine fuel filter and air came pissing out. I did the compression check on the copper rings for the injectors and no bubbles at all. I changed both fuel filters and started it back up and it ran fine and the needle was very steady again for about thirty miles. The needle has since started bouncing again the same way but the truck is running great. Any Help or advice on this would be greatly appreciated.

 

Well that's odd...

Where is your fuel pressure gauge hooked up? What is your fuel system setup? Stock pump etc?

Might just be a dying pump. As it gets hot it starts getting weak? Good thing for the fuel pressure gauge eh?

 

The fuel pressure gauge is hooked up at the upper filter. And yea i still have the stock setup yea that fuel gauge was the first thing ibought for the truck

 

It could be the sender going bad, it wouldn't be the first I've heard of it. Double check your connections for the gauge though, I've heard of grounding issues causing similar problems.

I would suspect the sender first, but since you said the truck was running rough too, I wonder if it was just coincidence (probably not) or something else is going on. Could always get a cheap mechanical gauge to pop on there to verify... I know harbor freight sells them.

Any work done recently to the truck? How's it running now? Still seem ok?

 

Its still running good the gauge is a mechanical gauge mounted outside the winshield. Since i bled the air the first time the truck hasn't acted up at all just the gauge started to go crazy again. Other ppl have told me that it was my fuel pump going out too but would that really cause air to get into the system?

 

Yes,

http://napaautotech-classsupport.com...-TIPS-1WEB.pdf

 

Good information, im gonna give it a shot Thanks

 

Awesome link there lilpooh!

 

Just installed my new fuel pump today and it fixed everything!!! Thanks for all the good info.

 

Glad to hear it! Thanks for updating us too!