Factory fuel pump

-
Boony405hp

Boony405hp

Well-Known Member
Joined
Mar 12, 2007
Messages
239
Reaction score
10
Location
Brisbane, Australia
I'm not sure who know's much about the factory fuel pumps, I have been running a walbro340 in tank pump + corvette wix filter/reg but have been having nothing but dramas with the car running. I have replaced everything but the pump, before I replaced it I do have a brand new pump from a ram which if I can get to work would help me confirm.

I did connect it yesterday but when it primed the pump it would rise to about 20psi and then drop instantly. Swapped back to the walbro today and that primes to 50psi and will hold pressure, nothing else was changed.

I've included some pics of the pump and wondering is there something that could cause this to bleed off internally. It has two pickups on the base of the pump, one with a sock filter and the other with a plastic fitting with multiple tee offs which sits in the base of the factory fuel container over the top of a rubber diaphram to which it looks like it pulls fuel through the bottom of. I did have it in the factory bucket but not sure if that plastic fitting pops off the bottom whether this would cause an issue, I'd think not but I'm not an expert on this stuff.













 
I'm running a modified truck pump in my Duster. I think the pressure is regulated in the top section which I don't see in any of your pictures.
 
boden said:
I'm running a modified truck pump in my Duster. I think the pressure is regulated in the top section which I don't see in any of your pictures.
Click to expand...

I had removed the top part which I know contains the regulator because it wouldn't fit in to the existing hole I had, I had the corvette filter reg installed in the fuel lines. But somehow the pump must be configured to work with that factory regulator??
 
The pump has nothing to do with reg. It should dead head at close to70 psi without factory reg installed. Not sure about extra intake part of pump, thats different from stock design I am used to. We use a different filter/reg on our systems, its a jeep part. I believe the vette filt/rg runs closer to 65 # and if I remember the later Hemi uses 58# and the first few years used 48#. What year was your donor?
 
magnummopar said:
The pump has nothing to do with reg. It should dead head at close to70 psi without factory reg installed. Not sure about extra intake part of pump, thats different from stock design I am used to. We use a different filter/reg on our systems, its a jeep part. I believe the vette filt/rg runs closer to 65 # and if I remember the later Hemi uses 58# and the first few years used 48#. What year was your donor?
Click to expand...

I do have the part number but I believe that's a 05 ram fuel pump assembly.

I have been running a walbro 255lph pump and with the corvette/filter reg, I constantly get 50psi on prime with this pump, but 58psi once the car starts. I thought my fuel pump might have been on the way out, so I replaced with another brand new walbro 255lph and it also primes to 50psi and has the exact same running conditions. Hard starting, takes a few goes to get the engine to fire up, when it does fire up it coughs and splutters stalls, after a few goes it does run and idle fine, it occassionally has a slight rough patch but then might sort itself out. Responds ok to light throttle application, but a decent hit with the throttle and it bogs right down and stalls. I have also replaced the filter/reg with another wix one. The injectors are the stock 5.7's that came with the engine. Had them cleaned, re-kitted and flow tested. Yet still the car runs like this.

Brand new battery, brand new pump, brand new filter/reg, new gas, rebuilt injectors, checked pcv valve, cleaned throttle body. It's starting to get beyond me and I don't know what to look for. No engine codes are up other than:

P0480 - Fan 1 Circuit Control
U0155 - Lost Communication with Instrument Panel Cluster (IPC) Control Module

These I believe would show on any car though as it can't see the factory dash or the factory fan setup. These have always been highlighted on the car and it's running the hotwire wiring harness.

I have live data but I can't make much sense of it.
 
That little black plastic gizmo is a jet pump used to keep the canister full of fuel so the pump's real inlet does not become uncovered. A small amount of fuel is diverted from the pump and shot through an orifice which create a small vacuum to SUCK fuel from the tank, through the Orange check valve and into the canister.

Many OEM pump canister's use a jet pump in some form or another to keep the canister full of fuel. LX cars use one to move fuel from one side of the tank to the other.



So if your little black Jet pump isnt being held TIGHT to the bottom of the cannister so that a decent "seal" exists over the Orange check valve, there's no vacuum to pull in fuel,,,and your canister will run DRY

Also if the Walbro 255 you put in does not a provision for the Jet pump to install,,your canister will run dry

 
After another look at this, i think you've removed a few hoses that could be causing issues. You might have close off the Big end on the jet pump for it to be more effective filling the canister.

 
Thinking about going with this fuel pump for a 2008 Jeep Wrangler.

Amazon product ASIN B00JPLEG6Y
It appears to have pressures and flow rates close to the 2008 Ram fuel pump and height of the assemble appears to be close to the height of the stock tank in my 1967 Barracuda once I weld in a recessed tray to mount the pump in the tank low enough to clear the trunk floor. Any thoughts

Specs for the 2008 Ram pump that I have found
Min Free Flow Rate 58.7
Min Pressure Range 55

Specs for the 2008 Jeep Wrangler
Min Free Flow Rate 55
Min Pressure Range 55
 
Last edited:
I did the factory pump in A body tank once, a total pita. Ever since the advent of these, I have never looked back. Takes 45 min to install pump/sender etc and 15 min to bolt in. No more worrying about leaking fuel sender as everything is above fuel level. Tank is baffled and requires no jet pump weirdness, just pump fuel out of tank and let unused back in. How easy could it be. PM for special FABO member Scummit buster deal.....or spend 2-3 days playing around with possible explosion while I have a cold beer and relax:thumbsup:

tanks Inc FI.jpg
 
magnummopar said:
I did the factory pump in A body tank once, a total pita. Ever since the advent of these, I have never looked back. Takes 45 min to install pump/sender etc and 15 min to bolt in. No more worrying about leaking fuel sender as everything is above fuel level. Tank is baffled and requires no jet pump weirdness, just pump fuel out of tank and let unused back in. How easy could it be. PM for special FABO member Scummit buster deal.....or spend 2-3 days playing around with possible explosion while I have a cold beer and relax:thumbsup:

View attachment 1714929529
Click to expand...

Thanks for the info Magnummopar, I checked out Summit's site. If I didn't already have a new fuel tank that would likely be the direction I would head. Shipped to my location for the tank, pump, sending unit and regulator is around $800 Canadian vs the approximate $300 Canadian for the Jeep pump plus my fab time to convert the tank I already have. I am also on the fence as to which fuel pump option would be the most reliable as I plan on doing route 66 with this car. Lots to think about I sure appreciate the input.
 
Canadian Cuda said:
Thanks for the info Magnummopar, I checked out Summit's site. If I didn't already have a new fuel tank that would likely be the direction I would head. Shipped to my location for the tank, pump, sending unit and regulator is around $800 Canadian vs the approximate $300 Canadian for the Jeep pump plus my fab time to convert the tank I already have. I am also on the fence as to which fuel pump option would be the most reliable as I plan on doing route 66 with this car. Lots to think about I sure appreciate the input.
Click to expand...

Yea our FABO member deal is $500 but not sure what Canadian dollar is at right now and you are correct, shipping anything to CA is expensive nightmare...so much for NAFTA, apparently only applies to items entering US, not CA.
 
Jeff sound like magnummopar is a dealer for Tank Inc., and he offers members a better deal. I found the pump I think I need on Tanks Inc web site and then searched the Summit Site. How ever I think Magnummopar will know exactly what pump your looking for and the price he said sounds cheaper that both Tanks and the Summit web site. My problem is I already have a new tank and the shipping to Canada. However I still have not ruled out Magnummopar's offer.
 
image.jpg
Looks like the tank I went with. Would have went with magnummopar if I knew about it before pulling the trigger. I went with the gpa-4 pump and tan-org sender. Both are lists on the tanks inc site. Not sure about summit.
 
We sell a ton of tanks and fuel line kits. Our kits are $100 cheaper than Tanks Inc and our AN fittings are about 1/2 of scumit. We have the correct fuel filter/regulator for Mopars, the LS1 vette type is wrong pressure.
 
These guys are great to talk to on the phone!! They are semi-local for me (very unusual) so I will be picking mine up in a month or so.

Thanks for posting!
 
Glad to help and look forward to meeting you this summer. You should try and schedule your visit with our back to 50 cruise week. Literally thousand cars in town having fun. Cool 74 and earlier only car parade. There is some pretty cool **** rolling around GP. Check it out on web site.
 
magnummopar said:
We sell a ton of tanks and fuel line kits. Our kits are $100 cheaper than Tanks Inc and our AN fittings are about 1/2 of scumit. We have the correct fuel filter/regulator for Mopars, the LS1 vette type is wrong pressure.
Click to expand...

Would please explain what you mean about the LS1 regulator being the wrong pressure? There are tons of guys running the LS regulator/filter without issue. What would make your regulator/filter more correct than say another?

I'm guessing you meant to say "We also carry a regulator/filter that we believe to be better in performance than the standard LS type commonly used in this engine swap."

Riddler
 
Its not a matter of performance, its a matter of having the correct pressure. The early Hemi's are supposed to have 48 psi +/- 2 psi and the later model ones are supposed to have 54 psi(off top of my head, might be 58) and typical LS type is 65+. Lots of people running Ls and may not have problems but I have seen some with problems. I am a stickler for things being correct. I would not worry about it if I was running a 6.2 or 6.4 but you can definitely get drive ability issues with earlier 5.7 like injector drip, rich condition codes etc. We just like to do things right and prefer a Mopar part over a GM. Its also less money!
 
Since at least 2004(cant find my 03 Hemi manual), ALL Hemi cars and trucks have operated at a fuel pressure of 58psi +/-5psi(FYI: Chrysler spec is 100% perfect with 63psi)
The popular Corvette filter/reg is also set to a nominal 58psi. I've used it on many different cars(srt-4 & hemis) with good results.

I custom tune a couple hundred different cars with DiabloSport every year at varying fuel pressures and would never think twice about seeing 5psi variance in fuel pressure especially at idle. In fact it's quite common for FP to be a few psi higher than spec just at idle but as soon as fuel demand increases slightly, the fuel pressure stabilizes closer to nominal.

I would NOT advise anyone running fuel pressure 10psi LOWER than what the factory PCM is originally calibrated for.
 
Thats why we sell the correct one for the early hemis and a different one for later model ones.....FYI 06 FSM says 58 +/- 2 psi not +/- 5 psi. Anyway, I was thinking we were talking early Hemi and I have to look pressure up in FSM for the specific year the cust has as they changed at least once...which is why we carry two different filter/reg units.
Funny thing, LOTS of jeep customers running Hemi with stock TJ pump and never a problem, I must not know mopar very well, only been screwing with them and building harnesses for last 18 years, only have about 30 years as a FI tech. Sorry for being so ignorant.
 
magnummopar said:
That's why we sell the correct one for the early hemis and a different one for later model ones.....FYI 06 FSM says 58 +/- 2 psi not +/- 5 psi. Anyway, I was thinking we were talking early Hemi and I have to look pressure up in FSM for the specific year the cust has as they changed at least once...which is why we carry two different filter/reg units.
Funny thing, LOTS of jeep customers running Hemi with stock TJ pump and never a problem, I must not know mopar very well, only been screwing with them and building harnesses for last 18 years, only have about 30 years as a FI tech. Sorry for being so ignorant.
Click to expand...


The only Hemis earlier than the 2004 is the debut platform 2003 Ram 1500,,,,and I'm pretty certain the 2003s run 58psi as well. So ALL Hemis should be running a regulator delivering 58psi +/-5psi and NOT 48psi, sorry that's just incorrect. All OTHER gas engines that used the JTEC PCM(magnum, 4.7, 3.7) ran lower fuel pressure,,but NOT Hemis(NGC PCM).

The factory NGC PCM's fuel trims can account for a misinformed owner running the wrong(lower) fuel pressure at idle, cruise, ie closed loop so the error might go unnoticed. Once headers up the VE and transport delay to the O2 sensors, drivability should improve with the CORRECT fuel pressure the PCM was calibrated for.

Unwittingly running a lower fuel pressure becomes the biggest issue at WOT obviously, since its open loop and there's no active feedback. Luckily the saving grace for an underperforming fuel system is that most stock tunes run fairly rich at WOT,,,,but again it's certainly NOT advised.

Now with that said if the engine has an aftermarket EFI(holley, fast, ect) and it's been tuned to account for a lower fuel pressure, then it's all good.
 
I'm not trying to bash you... as we need great vendors like you who can provide the products. I'm all in for supporting those who support us. However I can't sit idle and hear misinformation, etc. Like proven above all 5.7L and 6.1L Hemi's run at 58psi +/- 5psi. This is found in all FSM's.

I also took a look around and found a few posts you made and found this picture of your fuel system. The regulator found here looks very, very close to the Corvette regulator I purchased from Tanks, Inc about six months ago. Your fuel system posted above looks exactly like mine but I'm sure I paid more for it. :(

Anyway do you have a website to see your products and such?

Thanks,

Riddler

upload_2016-5-9_21-2-8.png
 
You must log in or register to reply here.
-

Back
Top