NOMIEZVR4

iTrader: (10)

Hey guys, I believe I have pin pointed my issue.
It all started after I installed my fuel pump setup. I just thought it was coincidence and went over the car. Checked plugs, wires and timing. I have not done a boost leak test yet. The only variable I added to the piece is the fuel pump setup. Before this, the car was running great!

My car has been running really ****ty lately. Now what I mean by ****ty is:
1. every morning it takes 2 tries to start the car. After a week of not driving it, still takes 2 tries. After a month of not driving it still takes two tries.

2. When my car is at/below quarter tank of gas, the car bogs, runs like crap. Acts like its running out of fuel.

3. After not driving it for over a month (45days) car sat with e85. Im thinking this symptom happened because gas went bad Going to fill up this week and try again.

When I'm WOT the car will sometimes pop. By pop I mean, lets say I'm in 2nd gear 3k rpm, I go WOT and by 4500rpms it will be a popping noise. In every gear this happens, it wont rev all the way up without hesitating.
Now even if I'm in 3rd gear cruising I hit partial throttle it will do that. Again this is randomly. I can hear the blow-off valve sputtering when it does this.

My fuel pump setup:
1200cc injectors
Full blown double pumper with 255 walbro's
6 an feed line
in-line fuel filter
stock return line
stock rubber line that goes to the saddle part of the tank
the second pump is hooked up to a hobb switch. It comes on at 5psi. I have hooked up an L.E.D. light to the second pump.

During the install I tested both pumps to make sure both pumps work. First I took the first pump and wired it up to the stock wiring, cranked the car and saw fuel coming out of the line. Did the same for the second pump.


Question:
By me having 6an feed line, and stock return line..is that causing any issues? Fuel pressure issues??

Any advice/suggestions would be appreciated?


Also, personally believe I complicated things by the hobb switch coming on at a certain psi. I've read a post by Ted B and how he was able to drill the white plastic fitting in the fuel pump assembly so he can run both pumps at all times. I would rather go that route. I know if I go that route I will need an AFPR, which I don't mind purchasing.

NOMIEZVR4

iTrader: (10)

After reading thread
"Full Blown Dual Pump System - Things You Should Know "
Figured out how to resolve 2. Need to turn the "y" fitting in the tank around.

Still unsure about the fuel line stuff...

n2oiroc

iTrader: (33)

stock lines are fine. make sure the pumps are sitting low enough in the tank, sounds like they arent.

NOMIEZVR4

iTrader: (10)

By running a 6an feed and a stock return, doesn't cause issues?

n2oiroc

iTrader: (33)

not at all. lots of guys do it.

NOMIEZVR4

iTrader: (10)

I believe after drilling out the "y" fitting I will HAVE to have an AFPR so it doesn't over run the regulator at idle.
Not sure if I can do that with the ss-line.

Steve220

Reason you're running out of fuel at 1/4 of a tank, if your venturi isn't working, the one side of your tank has loads of fuel in it and the other doesn't. This seems to be so over passed when people do double pumpers. The tank relied on the little pool the venturi sits in on the standard pump set up.

The other thing is running 2 pumps will increase the fuel pressure in the lines which may count for your rough runnings.

By venturi i mean this



I did test after test running the standard return line and found the resistance that causes high base pressure is the 2mm hole in it, you need to drill it out to 2.5 mm and the pressure will drop to what it needs to be

IFuXwiTuZ

iTrader: (3)

Steve your the man im gonna try this out hopefully it fixes my "unable to use the last 1/4 tank" problem i have