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-   -   Fitech fuel lines (http://www.ifsja.org/forums/vb/showthread.php?t=185223)

Pyrate2010 05-12-2018 05:43 PM

Fitech fuel lines
 
Is anybody using the stock fuel sending unit /pick up lines for their fitech ? the lines seem a little bit smaller than what is recommended. Thx, Joe

R69US 05-18-2018 10:34 AM

I did use the original (well, stock replacement) for the feed on mine. That said, on my drive from San Diego to Austin, the pump was getting loud and warm to the touch at the end of each ~500 mile day. Now, it's been fine around town for the last 2 years, and the inline pump is mounted as close to the tank as possible and right at level with the bottom of the tank. But I do believe it's on it's way out and I plan on re-doing the feed with the recommended larger feed line.

In all, I think it's probably pretty important to run the correct size line. It didn't cause any trouble at all until I made the cross country drive. It made it, and sounds fine when I drive it around but I suspect it adds just enough strain to prematurely kill the pump.

Also of note, I didn't see anywhere in the instructions where it talks about using the PWM feature with FiTech's inline kit, so I had it "off" at 74. When I talked with FiTech's tech support while on my cross country trek, they said you can adjust PWM down to "as LOW as 60" with their pump. The limitation would be making sure you're not going lean on AFR's due to the pump slowing down, but had I known this I believe that would have helped take a lot of strain off the pump as well.

babywag 05-18-2018 11:49 AM

Just my .02
If you're dealing with a stock-ish engine, and a big 'ole aftermarket pump capable of supporting 600hp, you very likely need to use PWM.
A stock-ish engine will never ever come close to needing what the pump can supply. Pump running 100% all time is likely a recipe for early pump failure.

On the 5/16" line deal, many FI vehicles out there came with them/run them without issue. However if using the big 'ole aftermarket pump, it is probably a good idea to increase to 3/8" especially if they recommend it.

On mine using pumps matched more to engine needs, I've had zero issues with either of my TBI wags. One is 3/8" and in-tank pump, Other is 5/16" external in-line pump.
But, they are OE type pumps capable of supporting stock-ish engines or mildly modified engines. Both setups have many (tens of thousands), trouble free miles on them.

If I was to install say a new FiTech system, I'd upgrade line size, but I would run an OE style stocker pump in the tank.
If FiTech is saying you can get away with dropping it to 60% that tells you a lot about how much it is overkill for the system, and just not needed until you increase HP significantly.

Just my opinion though

R69US 05-18-2018 12:11 PM

Quote:

Originally Posted by babywag
Just my .02
If you're dealing with a stock-ish engine, and a big 'ole aftermarket pump capable of supporting 600hp, you very likely need to use PWM.
A stock-ish engine will never ever come close to needing what the pump can supply. Pump running 100% all time is likely a recipe for early pump failure.

On the 5/16" line deal, many FI vehicles out there came with them/run them without issue. However if using the big 'ole aftermarket pump, it is probably a good idea to increase to 3/8" especially if they recommend it.

On mine using pumps matched more to engine needs, I've had zero issues with either of my TBI wags. One is 3/8" and in-tank pump, Other is 5/16" external in-line pump.
But, they are OE type pumps capable of supporting stock-ish engines or mildly modified engines. Both setups have many (tens of thousands), trouble free miles on them.

If I was to install say a new FiTech system, I'd upgrade line size, but I would run an OE style stocker pump in the tank.
If FiTech is saying you can get away with dropping it to 60% that tells you a lot about how much it is overkill for the system, and just not needed until you increase HP significantly.

Just my opinion though


Yeah I think you're 100% correct here, I'm just on a steep learning curve here and playing catch-up on this EFI stuff. I think it's likely that me having not known about the PWM option for the last 2 years had more to do with it than anything...once I got that dialed in I had the pump on the 'dashboard' for awhile and it dropped as low as 75% off-throttle with no change in idle AFR at the beginning of the day. At the end of the longer, hot days (it was ~100* across AZ and west Texas) it was starting to go lean at idle, but like I said I think my pump is going south on me already. The last day I had to keep PWM off to keep it from going into a lean roll at idle.

What kind of in-tank setup would you use for our stock tanks? I want to go that route if possible if I'm gonna tear into it again.

babywag 05-18-2018 12:43 PM

I've never messed with a JTruck tank, so hard to say? They're a different animal than the wags/cherokee tanks.
Guessing a GM pump could be stuffed in there without too much trouble though. Something from an LS car or truck maybe?

I like the fact that if I ever did have an issue with either of mine, any parts store likely has the pump on the shelf, or another store close by does.
They're MUCH cheaper than aftermarket too.
My '88 has a GM truck pump stuffed in there, and there are smaller(newer model) units out there.

If I can stuff an LT1 pump assembly in a boat tank lol, I'm sure finding something that'd work in a JTruck tank wouldn't be too bad.


R69US 05-18-2018 07:57 PM

Do you use the integrated fuel sender or just locate it separately from the stock unit?

babywag 05-19-2018 12:03 AM

The one living in my ‘88 looks like this...

R69US 05-20-2018 03:26 PM

Oh ok. So you just adapt a submerged pump to the stock sender. That's pretty slick. So I just need to find a GM vehicle with a similar style pump that uses ~58 psi for the injection system. TBI uses lower PSI, right?

babywag 05-20-2018 06:30 PM

regulators set pressure, not the pumps.
something from a later model car/truck w/ v8, and should not be terribly difficult to find & use.

The LT1 pump is compact, it’s 5/16” outlet.
It’s stepped up to 3/8” by larger pickup tube.
Can be had for $16-$70 depending on brand.
Used in ton diff. GM cars & trucks.
Just one example, several others.

Pyrate2010 05-21-2018 08:15 PM

I ended up cutting off the pick up and return tubes on a stock replacement sending unit, drilled out the holes and soldered 3/8 tubing bent 90 deg. to it.

babywag 05-22-2018 07:04 AM

Quote:

Originally Posted by Pyrate2010
I ended up cutting off the pick up and return tubes on a stock replacement sending unit, drilled out the holes and soldered 3/8 tubing bent 90 deg. to it.


That’ll work...

yossarian19 05-23-2018 08:13 AM

Yep, I did the same (modified stock sender to hang an EFI pump on it) and no complaints. I let the 5/16 tube stay in place (the old carb's feed line) as a return, unsoldered the 1/4" return, drilled the hole to 3/8 and bent some tubing.

Every V8 with EFI that I'm aware of came with 3/8 feed and 5/16 return. I don't need any other reason to do it that way, too.

When in doubt, imitate the OEMs as best you can.


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