My e99 lost another injector today.. After going through THIS I thought I had the problem licked. My fuel pressure is at 62PSI, without the truck running and just turning the key on. Is there a screen in the intake side of the fuel pump, that could possibly be clogged? That would allow a static pressure of 62, but might allow it to drop while the truck is under load. That's about the only thing I can think of... I'm wondering if I'm starving the injectors, when I'm working the engine. Either that, or maybe the fuel pump is just getting weak and can't keep up.


Any ideas?

 

There are 2 cylinder shaped screens inside the mixing chamber in the fuel tank that can get clogged over time. They can cause a volume restriction that will show good psi at idle but fall off under load.

Many of us do the in tank mods to remove these screens and simply add an inline filter between the tank and the pump that can be changed without dropping the tank. Welcome to guzzle's In-tank Hutch Mod Web Page

 

The PO of the truck did the in tank mods, but did not put an inline filter before the pump...

 

I don't think there's a screen on the back side of the pump. There is a check ball to prevent back flow, but I think that's on the front side of the pump.

Why don't you rig up a guage and take it for a test run at WOT and see what your fuel pressure does?

 

I ordered one earlier this week and it came in yesterday... I wish I had gotten time to install it then! The tester I had was only useable with the hood up..

 

I got my new FP gauge temporarily installed today and went for a drive. With the pedal to the floor and going up the side of a mountain, the fuel pressure only dropped by 8PSI.

The new gauge does read higher than the fuel pressure tester I got from A-Zone. The A-Zone gauge shows 62PSI with the key on and the new dash gauge shows 72PSI.. I have no idea which one is right, but I do have fuel pressure under load!

 

On a side note....


When I got home from my test drive, the truck was running a lot better. No lope/miss at all. I ran a CCT and it showed no codes. Before I left, I was still getting the Cylinder #1 fault.


What's up with that?

 

Chris, there is a screen on the back side of the pump. I can't remember who posted it but they had cut a pump they thought was bad apart and found the screen. To op that is a very good possibility, with no inline filter your pump would catch most of the bigger peices and cause a starving issue. Can you hook up a gauge to monitor pressure while driving?

 

I posted about it above.. FP only dropped by 8PSI under as much load as I could put it under... I backed out of it, when my EGTs got up to 1,200*

 

It doesn't sound like fuel pressure is your issue unless having the truck clear up is masking the symptoms. 8psi isn't enough of a drop to be that concerned with. If it starts acting up again you might try watching the fuel pressure while it's misbehaving to catch any intermittent issues.

 

Thanks Chris,

I'll get the FP gauge permanently installed when I get a pod for it. My triple pod is full.. I'm also getting a lot of ICP code P1211's. I posted about it HERE