I purchased a Quad Race and Commander with the fuel pressure kit from one of the good forum members here. I think I have everything hooked up, but there is a brown wire with a wire tap on it that I have no idea where to connect. It appears to be 1 of the 3 fuel pressure kit wires. The yellow wire with the ring terminal went onto the fuel pressure sending unit. The green wire was tapped into the center wire of the rail pressure gauge (dark green wire). Anyone know what that brown wire taps into?

I didn't get any instructions with the fuel pressure kit, but I did manage to find some info here online, but it doesn't mention this brown wire.

I'm on my way out to see which parameters the Commander is giving me, and then I'll post back if it looks like I'm missing something.

Jared

 

Don't hook the brown wire up at all. Leave it as you may want to use it later after we release a couple of updates.


Quad

 

Thanks for the quick response. My boost is good...32-33 on WOT bursts. Transmission temps and EGT are also working. BUT...my fuel psi is reading 2-3.

What could I have hooked up wrong? Sending unit mounts straight up/down in the hole on the cp3, right? Then I have the yellow ring wire sitting on top of the nut with the washer then lock washer then nut, tightened up. There doesn't appear to be any gas leaking from the fuel pressure sending unit. I'll pull it off and see if there is something in there possibly.

 

I am not sure exactly why it might read like that. I have had a couple people have sending units that did that but they had reason to believe that had plenty of fuel pressure.

So what we did is have them remove the teflon tape. It is a 1/8 pipe thread so technically it should not leak. Try that and see if it helps.

There are 2 things that I can think of that happens.

1.) Somehow the tape gets in the way and black the pressure somehow?
2.) The unit needs to ground to the pump and with plenty of teflon tape it does not get it.

Now the mfg of the unit says we do not need a ground as we provide a ground inside the Commander but, I am not sure they aren't smokin crack yet.

Worse case scenario is that it is a faulty sending unit or that you really have 2-3psi of pressure but, I do not think that is the case.

Also you know if you hook up the green wire to the middle wire on the rail pressure sensor then you can also read Rail Pressure. In the menu you need to select Inj PSI and it will show on the display as IPSI.


Let me know if that fixes it.


Quad

 

Okay, I tried taking off the teflon tape and reinstalling it. Fuel psi went up a tad and fluctates from 4-6.

I went back and looked at the rail sensor and it looks like I AM tapped into the middle wire. On my truck the middle wire is the dark green wire. If the sensor was sitting in front of me with the locking tab on the top, then the wires would be red (left), green (middle), and black (right). Am I on the right wire to be getting the fuel pressure reading?

I went back to the Commander settings to check out the rail pressure (IPSI) setting and set it to display that information. At idle it showed that I was around 6500 ipsi. So, I'm guessing I must be on the wrong wire if I'm looking to get the fuel psi reading. Which one should I be on there?

Jared

 

6500 psi sounds correct for Rail Pressure.

I think you have it all hooked up right and it seems to be working right.

WIth the COmmander you can read both low and high fuel pressures. You can even read them both at the same time.

Fuel pressure on the new trucks should be in the 6-8 psi range as they are a high colume low pressure pump.

Quad

 

Not to thread hijack, but.....


What kind of updates are we talking about

Any chance of a turbo timer soon???

 

Thanks Quad!

 

Hopefully right after SEMA we can start releasing the updates.

A Turbo Timer is well in the works, well we actually have the prototypes working. Now we just need time to finish all the fluffy software and get some test time in on some of them.

Quad

 

BETA testers? Look no further!

 

Jared,

What kind of pressure do you see on the high and low side at wide open throttle?

I am getting my kit from ups today and am very curious what my numbers are going to look like.


Quad: Are these "updates" going to be an extra purchase kit, like the FP kit, or are they going to be free downloads via the USB? If you can't tell us yet I understand, I am just curious, I want to buy a turbo timer, but will wait if one is on the way soon for the commander.

 

I'm anxious to get the turbo timer also. When is SEMA?

 

Man, I think something is wrong with my fuel system. My fuel pressure is reading 1-2 psi and down to zero sometimes!

My Quad Race Box was used when I purchased it, so I drove it for a few weeks before I realized I didn't have the most up-to-date flash for my truck. I was amazed at the performance gains. I took it off, meaning to send it in to Quad for the re-flash, but didn't get around to doing it for a couple of weeks. During that time I noticed my truck seemed sluggish and I was getting worse gas mileage, but I contributed it to just being in my head because I had gotten used to the extra power from the box.

So, a few days ago I got the box back from Quad and threw it in. It didn't seem like it had the get up and go that it had about a month or so prior...but again, I just thought it was in my head. Last night I threw the Commander on and now I'm getting low fuel pressure readings of 1-2 psi.

Anyone know what might be the problem?

I'm ordering the Glacier GFS-392 Comp Lift Pump with the Big Line Kit and 2-Micron Filter today just to be on the safe side.

Jared

 

What kind of boost numbers are you seeing at WOT?

 

All the way up to 33 which is what I should be seeing from what I've read here.