Engine/Transmission (1998.5 - 2002) FASS help?????

[KKunz]

How do I contact Fass? I do not have a dealer in my area and I need some help trouble shooting a low fuel pressure issue. I have the HPFP and with just the smarty and edge juice I can suck my fuel pressure down to 7psi, how does the HPFP regulate fuel pressure is there an internal bypass that could be stuck?

 

[MHoverson]

If you have an isolator on the line going up to your fuel pressure gauge be sure to blead the line going to it. I had the same problem when I installed my FASS HPFP, low fuel pressure. I tried everything, I thought, to fix it. I was ready to send it back when I got an email from the FASS rep here on the forum suggesting I bleed the isolator. I was sure it wouldn't work but it fixed everything.

Now the gauge reads 16 psi all the time.



Mark

 

[PRout]

Yeah, its pretty hard to pull the fass down to 7psi unless either the reading on the gauge is false (be careful there - maybe its right?), or there is some restriction like a plugged filter, or plugged fuel intake tube, or strainer before the fass. What you can try for grins & giggles is bump the starter and while the fass is running you can rock the truck side to side and listen for a change in the sound of the fass. If it sounds normal I would suspect maybe the isolator or fuel filter after the fass, if you hear it cavitating or changing pitch drastically while youre rocking the truck I would suspect a problem on the suction side. Hey, not scientific, but a quick down & dirty check. .

I added a manual bypass switch under the hood on the side of the fusebox to run the fass constantly for troubleshooting, purging air, or manually running the pump in case something automated quits. It comes in handy.

 

[PRout]

Only other thing I can think of is if it is possible for the fuel bypass valve on the side of the VP44 to stick open and be sending fuel back to the tank. . Doubt it but throwing it out here.

 

[KKunz]

I’m using the edge juice for my fuel pressure and also have a mechanical gauge on top of the fuel filter the both match at idle. I put a new fuel filter in but no change I’m running a Vulcan draw straw and 3/8 line. When cursing down the high way on level 1 at about 65mph I’m seeing 10-11 psi that’s why I was thinking the fass was bypassing too much fuel.

 

[PRout]

You're probably right. . Sounds like you may have the weaker 10lb spring. You want just over 13psi while cruising, and maybe with the weaker return ball spring it is truly allowing FP to drop to 7.

I would order the 15 lb spring and either keep it at 15 lbs or trim just a touch off and get about 14.

"IF" that turns out to be the problem.

 

[KKunz]

Is the 15 lb spring an option for the HPFP or just the FASS? I don’t know how I would change the spring inside my HPFP because the bolt have a safety wire with a tamper proof seal that I believe if are cut the warranty would be void.

 

[PRout]

Hopefully someone more familiar with the HPFP can chime in with better info. I just looked on the dieselpp.com website and didnt see how to change pressure on that unit. . Since FASS wants you to go through a dealer for support and there arent any in your area as you have indicated, I would probably PM diesel-dan for more direction. .

He will probably want you to do the 5 Gallon Bucket flow test.

 

[KKunz]

I tried to PM Diesel-Dan but he does not allow personal messages, So hopefully he will chime in so I can figure out what to do.

 

[PRout]

Thats pretty bad. . Fass customer service has been a fiasco from the beginning and I just went to their website at FASS - Fuel Air Separation System - fassride.com and they dont even seem to list a contact number anymore. No phone number?? At least when things got bad in the past you could get in touch with Dan, and he would take GOOD care of you, but now thats even hard to do. .

Wish I could help you more on your fass situation. . I advise calling your closest fass vendor and ask for help in a friendly way. If you are not satisfied then I would insist on being transferred to Dan in a more "firm" manner.

 

[KKunz]

WOW……. . looks like I’ve been hung out to dry on this one.

 

[LowFly]

WOW……. . looks like I’ve been hung out to dry on this one.

I have always said that if you need immediate assistance, please get a hold of your selling dealer (Or local dealer in your area). We have a network set up that they will get in touch with me if needed. I am only one person and we rely on our dealers to help me out with wnty and troubleshooting. If i feel the need to step in, i will. I can’t just sit behind this computer and wait for every post to pop up. Sorry. BUT I do my best to keep up with them…. .



I’m here now, and lets see what’s going on here……



I see this issue a lot, and dirty filters and gauges are the main cause of it. Not saying our pumps are never the issue, its just rare.



I see that you have double checked your juice with a mechanical. Have you taken a pre-filter reading? This would show you if the filter was causing the issue without changing a filter if it was not needed. ALSO just because the gauges match at idle, doesn’t mean they are matching at WOT... . which you can’t see because your gauge is mounted under the hood. I would check this. I have had Edge Juice with monitor’s reads low as much at 7 PSI under full load when compared to a mechanical gauge.



Check out these items and see what you find. If you get the same results…. have your dealer contact me with your SN and we will go from there. Thanks!

 

[KKunz]

Ok since this post I have installed ½ fuel line from the tank to fuel filter I also installed a draw straw. I’m now running a mechanical fuel pressure gauge; After all of this I’m still see the same pressures as before. I also noticed that the weep hole at the bottom of the HPFP is dripping diesel, I have cleaned off the bottom of the truck several times and I’m 100% sure the fuel is coming from the HPFP………. . Pleas help I don’t know what else to do.