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Walbro Fuel Pump install

11K views 18 replies 6 participants last post by  keithmac  
#1 ·
Ok here is my situation. I bent that damn line everybody has a hard time with and I ordered about 100 bucks in fittings to do the fix as shown on 3S wiki. That method involves securing the pump to a rubber hose instead of sealing up into a brass fitting. I dont see how it will line up properly on the bottom with either stock or walbro supplied rubber insultator. Maybe line up is the wrong word. Im sure it will line up, I just dont thing using a rubber line will give it enough support to where is will stay put and the insulator wont fall off since it will be fixed to a rubber line instead opf hard brass. If I just zip tie it to the Brass Arm do I even need the insulator?
Fuel Tank Studs & AN Fuel Pump Assembly - 3SI Wiki

This is the link I followed. In other words if I secured everything without touching the bottom support bracket the fuel pump would be dangling by a rubber hose, I dont think the insulator will do much good since it will tend to tip. Any suggestions?
 
#5 ·
Here is with the bottom bracket on. I can swing this thing with everything I got back and forth and it stays put. Only problem is it does not fit as snug as with the copper line and I cant use a zip tie cause it will pull the pump in and cause seperation at the insulator. What do ya think?
 

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#9 ·
Yeh you need to pack the back of the pump out and clamp it with a hose clip really.

I had a rubber line failure inside the fuel tank with my twin pump setup, would never use rubber line again submersed in petrol to be honest (I got some stainless braided teflon hose eventually and it will never fail!). Make sure that line is specced to run submersed in fuel, I asked around and could on find 1 manufacturer who would recomend a pipe for that application.
 
#17 ·
Should have listened! Ended up busting in the tank Christmas morning on the way to work 160$ tow bill, 1 1/2 hours late for work, tow truck messed up my shift linkage somehow, and a major headache. This has since been replaced with a SS line and runnning fine

Lesson for future readers!! DO NOT EVER use a rubber line inside your fuel tank, reguardless of what its rated for!
 
#10 ·
So i think I got this worked out. I went to lowes and bought a hard rubber stopper and used an existing hole in arm of the assembly to tighten it down. I then secured it with zip ties. I dont think its going anywhere now. As far as the rubber line goes, I also had some reservations about using it. The line I got is a top qaulity goodyear line thats rated for fuel. Ill let ya know if I run into any problems, im still waiting on the STM pump to rail kit and then I should be rolling agian! Thanks for the help
 
#12 · (Edited)
So here is the latest. I have the pump hotwired and have completely rplaced the line, filter, and fittings all the way to the rail with the STM kit. The car drives great with one exception. Initially after the car has been sitting for a few hours and I start it, it sputters( like its gonna die) then it will recover and go to a normal idle and then will drive fine. This only happens when the car is cold and it makes no difference if I turn the key wait a few seconds, then start. I can stop, turn the car off, and restart and it wont do it. I was thinking maybe a leak, but If I had a leak it would be pretty obvious( as I found out with a line fitting that wasnt properly secured) so I am at a loss. I am getting good voltage to the relay as well. Is this normal for walbro 255's? Battery is good to, its a new optima red top. Could I be overrunning the system because I am running a upgraded, hotwirred pump on stock injectors?
 
#14 ·
Mine has done that a few times and is a 255 hotwired, but I also have a AEM fpr which doesn't hold pressure (or much) as a safety feature. It's sputtered once or twice after only sitting a couple of days, but also hasn't sputtered after sitting for over a week. So... I dunno. I know for me though, the pump doesn't provide fuel pressure until I'm trying to start the car. I can turn the key to the on position all I want and it doesn't build pressure. I'm not sure if that's due to the hotwire job or what.
 
#15 ·
From what ive been reading its looking like its normal. I plan to get a FPR and new injectors one of these days when im ready to get it tuned. Until then I may get a decent fuel pressure gauge to check and see where im at. I have two ideas on this
1. the fuel pump hotwired is overrunning the FPR and or injectors on cold start, and the engine is having to playing catchup( therfore creating the sensation that the engine is flooding)
2. For whatever reason the line/ pump losses pressure more than it sould. So when we go to start our cars, it uses what little fuel it has until proper fuel pressure is obtained (creating sensation of not getting enough fuel)
I would really like to know if there would be any long term effects of running super rich, super lean even for just a few seconds, every time you start the car?
Im talking out my ass here, someone with more knowledge of these systems please edumicate us.
 
#16 ·
Bout the only way to avoid that potential lean condition I would think would be to wire your fuel pump up to a flip switch that you can flip on momentarily to power the pump and build pressure prior to starting.

Only way to know for sure what is happening is with fuel pressure gauge.
 
#18 ·
Damn sorry to hear! Thanks for updating this thread though. I'll be sure to take that advice when I install mine.
 
#19 ·
Yeh I has rubber lines supplied with my twinpump kit.. Emailed several hose manufacturers after mine split to see if they had anything rated to be submersed in fuel, only one did and I would have had to send the pump assy off for them to fit it.

Normal fuel hose has a fuel resistant inner core, a re-inforced mid secion and an outer sheath, from what I saw the outer sheat and mid section deteriorate rapidly when say in fuel..