I just installed the Big Line Relocation kit from Genos, putting my lp under my cab just in front of the tank. I have my Westach fp sending unit tapped into the elbow mounted to my vp44 and my 5# dummy light on the inside port of my filter. My problem is this: When I start the truck up for the first time of the day, my gauge shows the pressure drops whenever I accelerate - hard or soft doesn't matter - and it drops down to zero quickly but my dummy light does NOT come on. After the truck is warmed up, the gauge never drops below 7#. I know my dummy light used to work before because that's how I knew to replace my lp when I installed the relocation kit. This westach is a electric sending unit...so could it be caused by the heating element being on with the first start of the day? Thanks.

 

You could have low voltage issue to the pump, but it's hard to say.

You will see pressure drop with any factory pump setup. I would check for a restriction ont eh intake side of the pump, but I am betting you have a fuel filter issue. When did you last change it?

Dave

 

Actually, I changed the filter, lp and installed the relocation kit all at the same time. When I am driving under normal conditions, my pressure is usually around 9-10# and drops to 6-7 when I accelerate...then it comes back up. Sitting at idle it is around 12-13#. I do notice that sometimes, my pressure reads at 7 when I am crusing on the fwy and if I accelerate, the pressure goes up...confusing, but thinking maybe it's a pcm issue? Thanks

 

If you are reasing between 5 and 7 psi at cruise and when you stomp on it and return the throttle to see normal pressures, the lift pump is shot.

Been there, done that.

Dave

 

ding ding ding we have a winner!!!!!!!!

 

Crap...I really don't want to hear that..specially since the pump is brand new...this is the first time it's been mounted/used. I think before I pull the pump, I will hook up my Vulcan manual fp gauge to the vp and see if I get the same readings. I'm so sick of this crap. Thanks for all the input.

 

Yes, double check the pressures. It's possible to have a bad gauge or isolator.

I only went through 5 stockers in 40K miles. My new pump solution has 60K on it and the pressure is rock steady.

Dave

 

hook up some clear line in the pressure side of the system, and watch for air bubbles. I have just done a bunch of work to my own truck, and had an air leak on the vacuum side of the lift pump. this is after a big line kit, a draw straw, and all the other wonderful fixes for fuel system problems. I have not totally solved the issue yet, as I ran out of time today, but, I ended up putting new lines in between the top of the tank and the strainer, then the strainer to the lift pump on the frame. the only thing left to do, is pop the draw straw, and seal the connection between the pickup tube and the pickup fitting in the tank.

Each joint I came to, as I re-hosed / sealed it, lessened the amount of entrained air at the injection pump. You can hear the lift pump cavitating, if you bump the starter, then let the lift pump run up to pressure.

Good luck with it

 

Okay, great news...seems that the Westach elec fp gauge I bought does not like to be mounted in any position other than vertically. Doesn't make much sense since the directions say to mount it to the inlet of the VP which would put it sideways. Anyway, I reversed the line between the filter and VP to put the ported elbow on the outlet of the filter which allows the sending unit to be perfectly vertical (unless I roll my truck...LOL). Now my pressures read normally...12 at idle, 11 @ 2200rpm, 9 WOT. I confirmed these readings with my vulcan manual gauge hooked directly to the inlet side of the VP before I turned the line around. I am so relieved! Thanks to everyone for their input. Hopefully, this lp will last longer than 4 flippin months! Saving the receipt in a safe place just in case...LOL.

 

Glad to see you have it working. I was going to suggest that it is the sender that is giving you a headache. This is why I chose to go with mechanical gauges. Any time someone says, god my pressure is low! I say, double check with a mechanical gauge.
-P

 

yes, I agree...mechanical is always better than electrical...unfortunately, the price difference is $100 and I just did not have the $$ at the time. I figure with the 5# dummy light i already had, it'll be close enough and good enough coverage to protect my vp. Hopefully, I'm done with my fuel system for a long while.

 

Hundred bucks?.. I bought my mechanical gauges for less than $7 apiece from Surplus Center, plus $5 for shipping. Granted, they are not the sexy-looking Dipricols or Isspro and not always come with a light but they work just fine. The one I bought is actually an Autometer brand. An in-cab gauge would cost me the total of $15 to get and install, including fittings and tubing.
-P

 

Hey now...you need to give me their website addy or contact number. I bought my elec gauge for $60 I think...came with everything I needed to install and mount with nothing pretty. I'm looking to add an EGT gauge and maybe a boost gauge. Sheesh, at those prices, I'll put in a gauge that tells me if I'm sitting straight in my seat! LOL. Thanks.

 

Here you go:
http://www.surpluscenter.com/sort.as...s&keyword=NFGA
My fuel pressure gauge says "Water" on it but I don;t care. Works the same, and the 35 psi range is about perfect, at 15 psi the needle is right in the middle. The one I bough I think is Item# 28-1573-D.
-P