Fitech FCC fuel command center issues

[babywag]

stock GM TBI application for 5.7l engine silverado.
It was a PITA to do in-tank, tank opening is VERY small.
That's why I just did a frame mounted on '90 lol.

[ShagWagon]

I ran a 3/8 return off my TB, then channeled it into 5/16, then to my hardline back to my sending unit modified from the stock 1/4 to 5/16.

The fitech runs at 58psi. I believe most GM systems run 18-22psi(?).

My pump is 60 psi Delphi. Most others are 80-100. I think might be too much pressure deadheading the pressure regulator with too less return line might be causing issues.

Also there's a PWM (Pulse Width Modulation) setting. Has to do with the speed the pump pumps. Not sure how or if this factors but it may. It can be changed with the handheld. Recommended 40PWM for FCC and 75PWM for other pumps.

I just put in the new in tank system a few days ago and haven't tested it much just a few grocery gets. Headed up the river tomorrow will see how it does at some more extremes.

I'm running a Novak which I had to add two inches to pickup tub to make it hit bottom of the tank. I also modified the hot wire seal. Didn't like that it was a loose seal and that they put the nuts on the bottom so I changed it to the nuts on top and the screw head on the bottom so I could remove the + post without pulling out the whole bolt, sanded down the spacer some and added an extra washer and rubber washer to the top for a snigger fit. Is a good setup so far. Noise is completely non existent.

I ordered the parts to make one out of my original sending unit just for fun because I couldn't decide to make one for about $170 with a walbro 80psi, walbro install kit and bulkhead for wire sealup or go with the Novak pump. I ordered it all the same day and Novak showed up first so I had absolutely no patience and went with that one.

I'll probably be building this later this week and will try to put up some pics....

[ShagWagon]

I don't think the mechanical pumps enough fuel at idle. Then engine turns too slow. Then the FCC sump level slowly drops heating the pump till it croaks.

Can't be good for the pump life either.

Rid yourself of it.

I dealt with it for about 9 months wondering why my stuff didn't work right.

I just went on a trip all over the mountains using a full tank of gas and all went well with no problems at all with my in tank unit.

I checked at the top of the mountain after some controlled heat abuse and the fuel intake was warm but not hot.

[babywag]

The fitech runs at 58psi. I believe most GM systems run 18-22psi(?).

My pump is 60 psi Delphi. Most others are 80-100. I think might be too much pressure deadheading the pressure regulator with too less return line might be causing issues...

Pump ratings show psi purely for information.
They(pumps) do not set the fuel pressure.
It is simply to give an idea of output/flow @ psi x

Regulators set pressure.

[ShagWagon]

Yeah it gets complicated somewhat on those.

The fitech TB has a pressure regulator built in at 58psi. They ask you use a pump >58psi

Delphi was 60 psi and went by xxGPH. Goes by gallons per hour But later in the specs said 73psi-102psi turbine (whatever that means)

The walbro just says 100psi and 255LPH goes by liters

[babywag]

it just tells you output/flow (pump size)
a 35gph (62psi) pump = 132lph
a 255lph (80psi) pump @ 58 psi = ~190lph
In a nutshell how much hp they will support.
There is also the too much pump for stock/mildy modified.
@ low flow rates they can heat up and cause issues.
If you're running say 250hp you don't want/need a big pump. Like a 340lph.
PWM capable pumps are utilized to reduce the output(to reduce heat) when the high demand isn't required.
Otherwise the pump can overheat and die.

[chuckdds]

Well- I scrapped the FCC and installed an in-tank pump/sender from Novak that is specific for FSJ's-

Absolutely no issues. Drove all day in the 90+ heat. Start, stop, traffic, etc.

Finally, I am a happy Grand Wagoneer owner- for the time being...

That POS Fitech FCC will be heading back to Summit this next week.

[ShagWagon]

The Novak pickup tube is too short. I redid mine before I installed it and added about 2" to it so that it reached the bottom of the tank.

I had this issue when I bought a new one from TGW last year. The Novak is the same sending unit. It's 2" shorter than the stock pickup.

It should run out of gas on you at 1/4 tank left.

I would carry a 5gal can of gas with you and run it out on purpose to see exactly where your gauge reads when it runs out. If it runs out on you and your gauge reads the bottom okay then you can keep it as is if you like but there will still be 2" of gas in the tank. At least you will know where your gauge is when you run out for sure. Better than surprise!

Mine ran out bone dry on the hwy and my gauge was on 1/4. I put 4.5 gal in that I had in the back just for this propose. and it started right back up. I already extended my pickup I didn't adjust my float so I have to calibrate it. I drove it home and I'm going to drain it and manually calibrate my gauge by bending the float arm till it reads empty when it's bone dry, then add one gal and see if needle slightly moves, then another gal and on the third the light should turn off. Then your light will turn on letting driver know to get gas with 3 gallons left in the tank and you can bank on it.

[ShagWagon]

I took these last year when I installed the sending unit from TGW. I had put the original stock one back on to extend it to the bottom. It too ran out at 1/4 tank before I did that. Then I had to modify the float arm calibration to the fuel gauge.

[TexasJ10]

So using the old sock allowed you to use the last quarter tank? I thought the pump would suck air through the screen anytime the fuel was below the actual pickup tube.

[nightglide]

Well- I scrapped the FCC and installed an in-tank pump/sender from Novak that is specific for FSJ's-

Absolutely no issues. Drove all day in the 90+ heat. Start, stop, traffic, etc.

Finally, I am a happy Grand Wagoneer owner- for the time being...

That POS Fitech FCC will be heading back to Summit this next week.

Are you running the Novak pump with pwm? Are you just using the orange fitech wire or are you using a relay?
Thanks
Owen

[ShagWagon]

Are you running the Novak pump with pwm? Are you just using the orange fitech wire or are you using a relay?
Thanks
Owen

The orange wire is controlled by fitech handheld. It controls pwm. I reset to 75 as instructed to for inline and intank pumps. FCC was 40.

I had to splice in about 3' to make it reach the Novak Hotwire. I thought to re run the orange wire down passenger side and across above the tranny it might have reached but I kept it my original way across the harness in front of radiator and tied in at driver fender.

[babywag]

Be 100% sure your new pump supports PWM. If it doesn't you'll probably kill it.

[ShagWagon]

Be 100% sure your new pump supports PWM. If it doesn't you'll probably kill it.

If it doesn't then what settin should be used as a standard? 75?100? I never checked on that. The default is something like 75.5

Run it to a steady ignition activated 12v?

I rigged straight to the fitech pump wire in hope that an accident would cut the fuel pump if fitech would know this if you became overturned or hit hard...

[chuckdds]

guys I will check with my mechanic to see what he did. I know that I am still running PWM at 40 right now on the handheld.