Fass installed, now no A/C and 25psi fuel press!

[CIverson]

As the title states. First time I started it up idled at 19psi. Next time I started it up and took a ride pressure was at 25psi the entire time, never varied.



An added plus to this is that the A/C doesn't work now, it works for a second if you turn it off then back on, and when the truck is not running but the key is on, the pump continues to run and give 25psi, doesn't stop.



Edit: Should mention this is the 95gph standalone unit, and the truck is an 03 HO

 

[rbattelle]

Hmmmm... this is going to take a little diagnostics. I think the FASS has a fuel pressure regulator on it. If this is true, you need to see if it's functioning.



It's not clear why A/C would be affected by the LP fuel pump... . that is weird. My recommendation is to work on the FASS first, then worry about the A/C later.



-Ryan

P. S. Don't you just love it when you take a machine that's working fine and decide to upgrade it and it seems like the whole thing goes to crap? I feel your pain...

 

[SAlex]

My 2005 pump only Fass runs as soon as I turn on the key and doesent stop, you can hear it get up to pressure and then stop the pump but something is still running after build up. Also the instructions for the 4. 5-05 suck! The cheesy wiring/fuse jumpers suck. But so far the pump works excellent and havent had my 5 psi led come on at all. Steve

 

[CIverson]

P. S. Don't you just love it when you take a machine that's working fine and decide to upgrade it and it seems like the whole thing goes to crap? I feel your pain...

It's happened before on other projects, yet I still continue to do it, sometimes I wonder about myself

 

[rbattelle]

you can hear it get up to pressure

That's interesting. My system doesn't lose pressure when it's off (when I turn the truck on it's at 13 psi immediately). I guess the FASS bleeds off pressure back to the tank. Interesting.



Sorry to get off topic (already!).



-Ryan

 

[Gary - K7GLD]

Where are you picking off power to run the FASS?

 

[CIverson]

Where are you picking off power to run the FASS?

Positive and negative right off the drivers side battery like the instructions say.



Only thing I did different was trimmed the wires before crimping on the ends so I didn't have excess wire laying all around.

 

[CIverson]

Went out again and started the truck, Key on, and the pump stopped running this time. It turns on, the guage goes up into teh 30's real quick, then settles to 3psi. Truck starts and 25psi again.



Still no A/C, but the check engine light came on.



In addition to the codes that have been in there awhile, there was an 0606, which I've seen before from the TST, but also were:



0341: Camshaft position sensor circuit range performance



0647: A/C clutch relay control circuit high

 

[Tomeygun]

Went out again and started the truck, Key on, and the pump stopped running this time. It turns on, the guage goes up into teh 30's real quick, then settles to 3psi. Truck starts and 25psi again.



Still no A/C, but the check engine light came on.



In addition to the codes that have been in there awhile, there was an 0606, which I've seen before from the TST, but also were:



0341: Camshaft position sensor circuit range performance



0647: A/C clutch relay control circuit high

Mark at TST is aware of the A/C problem... we know that it is more apparent with trucks that have the FASS and the TST (very common) - I have the same situation, A/C worked very poor - Them I did what many of us have found to work (but I was trying to find an easier way, but gave up)



Move the TST ground to the inner dash frame (by your knee) - And i'll be a monkeys uncle, my A/C is back to ice cold - Dont ask why, I have no idea why it works... . But Mark said it is common on truck with TST/FASS



Anyway, try that and let us know

 

[rbattelle]

Move the TST ground to the inner dash frame (by your knee) - And i'll be a monkeys uncle, my A/C is back to ice cold - Dont ask why, I have no idea why it works... . But Mark said it is common on truck with TST/FASS

Holy cow, that is weird, wild stuff! Doesn't this sort of thing make you a bit nervous about the side effects of having such a device?



-Ryan

 

[CIverson]

Mark at TST is aware of the A/C problem... we know that it is more apparent with trucks that have the FASS and the TST (very common) - I have the same situation, A/C worked very poor - Them I did what many of us have found to work (but I was trying to find an easier way, but gave up)



Move the TST ground to the inner dash frame (by your knee) - And i'll be a monkeys uncle, my A/C is back to ice cold - Dont ask why, I have no idea why it works... . But Mark said it is common on truck with TST/FASS



Anyway, try that and let us know

Fixed the A/C, that is freakin weird, thanks tomeygun!



BTW: Instead of the dash, I used a body ground bolt right next to the fuse box, much easier than running the wire into the cab, since I've got bundles of wire going through the firewall already!



Gonna call the place I bought it and see what they have to say about the Pressure.

 

[Tomeygun]

Holy cow, that is weird, wild stuff! Doesn't this sort of thing make you a bit nervous about the side effects of having such a device?



-Ryan

Worry? That only for worts :-laf



Honestly, not really... Just like when you mess with the internals of a Holley carb, sometimes you have to tweak alittle to be perfect

 

[Tomeygun]

Fixed the A/C, that is freakin weird, thanks tomeygun!



BTW: Instead of the dash, I used a body ground bolt right next to the fuse box, much easier than running the wire into the cab, since I've got bundles of wire going through the firewall already!



Gonna call the place I bought it and see what they have to say about the Pressure.

I did that too, But that only made it cool, not ice cold... try the dash ground and see if it is even more cold, Then again maybe you found the easy spot

 

[CIverson]

I'll try that later, once I get the pump worked out. If only the place I bought it from would talk to the people at FASS and get back to me! they are taking their sweet time :{

 

[Tim]

Holy cow, that is weird, wild stuff! Doesn't this sort of thing make you a bit nervous about the side effects of having such a device?



-Ryan

Not really. Control circuits for computers are really sensitive.

 

[CIverson]

Finally, got an answer, and I am being sent a Spring for in the pump. I was told they had this happen before. So now I get to wait for that and change it out.



Hopefully that fixes it.

 

[JonKing]

What pressure is the FASS pump supposed to run at? I just installed one on my 05 and it pegs out my 15 psi gauge. And, also I agree the instructions SUCK, :-{} ,not to mention two of the parts where missing. The power supply hook up is a joke, as anybody hard wired in the pump if so what wire did you use?

 

[CIverson]

What pressure is the FASS pump supposed to run at? I just installed one on my 05 and it pegs out my 15 psi gauge. And, also I agree the instructions SUCK, :-{} ,not to mention two of the parts where missing. The power supply hook up is a joke, as anybody hard wired in the pump if so what wire did you use?

15 is what I had heard.



To update my problem. I got the new spring, installed it, and not sometimes it will run at 19psi, and sometimes 25, so I guess I need to call them again.

 

[rbattelle]

Methinks there's a bit of quality control problems over at DPP. Seems like the problem rate for FASS related parts is unusually high...



-Ryan

 

[CIverson]

Methinks there's a bit of quality control problems over at DPP. Seems like the problem rate for FASS related parts is unusually high...



-Ryan

If I hadn't been driving with mine installed for a while now, I would be returning it and looking for a different solution.