Engine stumbles after twin fuel pump setup.
Thread Starter
Staging Lane
Joined: May 2018
Posts: 88
Likes: 8
Engine stumbles after twin fuel pump setup. 02 Silverado
I just completed the fuel system and the engine stumbles at the touch of the throttle.
Here is what I've done:
1. Two fuel pumps plumbed into a Y block. -6's in and -8 coming out.
2. -8 through the fuel rails and -6 coming out into a boost referenced fuel regulator. I used the stock feed line as a return line and removed the fuel filter then spliced the lines back together.
3. I ran new 10 gauge wire to each pump.
4. Two 40 amp relays running in parallel.
5. I went around the stock relay. Found the stock power supply wire from the computer and supplied it to the relays.
Its hard to believe I'm not getting fuel now but that's how it acts. I also am planning on activating the second pump via a pressure switch. Its not wired in as of yet so the second pump is not being used but is plumbed inline and ready to be.
The pressure gauge rises to 60 psi when I blip the throttle and at the same time the engine falls on its face. Base pressure is set to 43.5.
I just completed the fuel system and the engine stumbles at the touch of the throttle.
Here is what I've done:
1. Two fuel pumps plumbed into a Y block. -6's in and -8 coming out.
2. -8 through the fuel rails and -6 coming out into a boost referenced fuel regulator. I used the stock feed line as a return line and removed the fuel filter then spliced the lines back together.
3. I ran new 10 gauge wire to each pump.
4. Two 40 amp relays running in parallel.
5. I went around the stock relay. Found the stock power supply wire from the computer and supplied it to the relays.
Its hard to believe I'm not getting fuel now but that's how it acts. I also am planning on activating the second pump via a pressure switch. Its not wired in as of yet so the second pump is not being used but is plumbed inline and ready to be.
The pressure gauge rises to 60 psi when I blip the throttle and at the same time the engine falls on its face. Base pressure is set to 43.5.
What does the fp do when you pull the vac reference line off?
Touching the throttle w/ 1 pump on, and the psi jumps to 60. A problem. Base at 43, and it jumps to 60, is way too much rise.
w/2 pumps on it doesn't rise, but shows idle at 60psi.
It looks to me that 2 pumps are overrunning the reg, and/or the return line.
Data log it, and see if there's any tell tale info.
Touching the throttle w/ 1 pump on, and the psi jumps to 60. A problem. Base at 43, and it jumps to 60, is way too much rise.
w/2 pumps on it doesn't rise, but shows idle at 60psi.
It looks to me that 2 pumps are overrunning the reg, and/or the return line.
Data log it, and see if there's any tell tale info.
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Thread Starter
Staging Lane
Joined: May 2018
Posts: 88
Likes: 8
With vac line unhooked it’s set to 43.5. Pressure seems to be looking fine with 1 pump and with two pumps pressure rose to 60. I won’t be cruising with two pumps on just trying to see where the problem is coming from. Would there an over fueling somehow with the bigger supply line? My scan shows my motor going lean, not getting any fuel but from the video pressure didn’t drop it rose from say 41 to 43.5 like I set it.
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Thread Starter
Staging Lane
Joined: May 2018
Posts: 88
Likes: 8
Very well could be but, prior to the fuel line install I was running a 3/8 feed with 5/16 return. I did increase both sizes and regulator is still set to what it was before the fuel lines were changed. I did remove the fuel tank float assembly along with the tank pressure sensor. I set those coded in engine diag to no error reported. Would either of those changes cause my problem? My float previously was hooked up just wasn’t working. Was wanting to take the truck out to the races one last time before the track closed. How far can e85, 1 walbro 450 and Deka 80s get me if I swap tech back to what it was before? I can increase the pressure a little to squeeze more out of the injectors. 10 gauge wire will remain in place.