Help Fuel Pressure is going away

[SandawgK5]

I just noticed that my fuel pressure is dropping to around 30# from an idle pressure of 68# under about 1/2 throttle.

My HFCM "sounds" fine. It has started to get cold and I will be driving from Washington to San Diego in a week and a half so I have started using Power Service additive with anit gel for 2 tanks now.

Could the additive have knocked something loose and clogged my fuel filters? I have had the blue spring installed for about 3 months now and with Matt's SRL I was seeing 72 at idle and 55 at WOT. I am afraid to go below 45# so I can't get past 1/2 throttle.

I think I should change the filters at a minimum since it has been about 4K since they were done last.

I also noticed that my boost will only build to about 20# could low fuel pressure be a contributing factor to that?

Also if I had to replace my HFCM how long should that take and are there any special tools. I have been wrenching for some time and I am pretty confident with my abilities so I am not a beginner.

Thanks for the help

Dik

[fixxxer-upper]

I recently had pressure problems with the fuel delivery on my truck. I pulled the upper filter out of the bowl and discovered that the fuel return standpipe was broken and missing an oring.

[justa03]

The HFCM is pretty easy to take out, drain it, 3 13mm nuts and remove the fuel lines. I wouldnt mess around too much with fuel pressure or your gonna run into injector issues. The standpipe in the fuel filter housing isnt a bad thing to check but have seen plenty of HFCMs go bad.

[SandawgK5]

I replaced the filters today. The standpipe on the upper filter is good and still there. I did have some brown stuff and what looked like some sediment in what I drained from the HFCM. Also the water seperator filter was not a motorcraft it was a Napa Gold and did not have the oring on the fwd end nor did it have the membrane.

I will see if that worked when I drive to work in about 1/2 hour, if not I guess it is time to order a HFCM.

Thanks

Dik

[SandawgK5]

So on the drive to work tonight my fuel pressure is doing the same thing. The truck is very driveable, but as soon as I stand on the loud peddal pressure goes away quick.

I have a new HFCM on it's way from Tousley and I will change it out and post up my results as soon as it gets here.

Do I need a special tool to disconnect the fuel lines from the HFCM? They look like the push lock style on gasoline engines.

Thanks

Dik

[justa03]

You got it!

[Razorsedge]

Originally Posted by SandawgK5

So on the drive to work tonight my fuel pressure is doing the same thing. The truck is very driveable, but as soon as I stand on the loud peddal pressure goes away quick.

I have a new HFCM on it's way from Tousley and I will change it out and post up my results as soon as it gets here.

Do I need a special tool to disconnect the fuel lines from the HFCM? They look like the push lock style on gasoline engines.

Thanks

Dik

Just get you one of those disconnect tools from the parts store. It's a pretty easy swap. I had the same problem as you and a new HFCM fixed the problem. I couldn't tell by driving the truck that I had fuel pressure issues so I'm glad I got that fuel pressure gauge!

[SandawgK5]

As soon as the HFCM arrrives I will post the results up here

[SandawgK5]

I got my HFCM today and it took me a whole hour to change it out. Not too bad since I did it in the dark.

The movers come tomorrow to load all of our stuff since I am moving to San Diego on Friday and my shop lights were boxed up somewhere. I had to use my cell phone to see the release tab on the pump connector.

All in all not a hard job, hardest part was getting both hands around the D shaft to get the fuel lines released and off. I also didn't notice that the lines are two different sizes so oddly enough two of them were harder to release

Anyway, the verdict is...

It appears it was the HFCM. My idle pressure rose about 10# and is 72-75 and WOT with Matt's SRL it drops to 50-52. Throttle response is better but I still only build about 22# boost in first and second then jumps to 26 in third on up. I took it out and beat on it to cycle the vanes and to make sure the fuel pressure would hold. The only time the needle wiggles is if I get on it hard even moderate acceleration it is rock steady.

Thanks for the help

Dik