I just finished dynoing the car. It made 522whp. I took it off the dyno and when I went to turn it on I noticed my fuel pressure gauge reading 10psi when it was reading 40psi a few minutes before. I thought I might have a gauge issue so I drove the car. I couldn't even make it 10 feet without it sputtering. I just cleaned the fuel filter and checked my pumps and wiring. I can't figure it out. Has anyone had a similar issue or might know what's going on? I'm trying to get the car ready for nscra next weekend.

Thanks

 

more info on the setup, are you using dual pickups and check valves? if you are running dual pumps one could have failed and pressure is simply going through it and back to the tank through the pickup. dual pumps need to be isolated from each other you can run them into one fuel line, as long as there's a check valve after each pump

 

I'm running a full blown dual walbro setup.

 

is there any way to check each pump apart from the other? it sounds like one failed pump, the pressure is so low because most of the pressure would be bypassing through the failed pump

 

what regulator are you running

i remember someone using a weldon regulator and he was having the same issues

 

I'm running an sx regulator. Btw I crimped the return and fuel pressure didn't rise so I don't think its the regulator. I tried to disconnect one pump and I hit a ground with it by accident and I think I just ****ed up my ecu. The fuel pumps don't even prime now.

 

ewwww no bueno

 

One little problem turning into a bigger problem.

 

One or both of the magnets can come unglued in the pump... been there did that on E85

 

Have seen many times where one of the hoses came loose on a pump and only show about 10 psi at the rail...I find it hard to believe you made 522 and then as soon as you took the car off the dyno the pump just instantaneously failed.

Take the pumps out of the tank, and check ALL hoses and clamps...also make sure you have the wiring correct to both pumps. Should be a single wire from the MFR to Twin Relays (one for each pump unless you have a single relay that can handle the current of two pumps). Relays should get their main power direct from the alternator (fused).

You blew a fuse...dont get too excited

 

Sorry but I blew c24 on my ecu not a fuse I checked and replaced the main relay. I made numerous 500whp pulls on the dyno and after we unstrapped the car and I went to drive it off it started sputtering and said 10psi. I really really hope it's just a hose on that got disconnected

 

Xenocron ftw alternator fuse blown lol thanks

 

Now I have to go on the headache and take out the dual walbros and check the hoses

 

it's usually when a pump is spinning down is when it fails, those pumps run at an ungodly rpm, and sometimes when they are slowing down is when the rotor comes apart, or other failures occur, I hope it's just a hose, pumps aren't cheap

 

I replaced the Alternator fuse and it still doesn't prime

 

I think the fuel socks on the walbros aren't flat against the bottom of the baffle. If you can add 5 gallons of E85 and see if that fixes the problem. If it does then that's your problem.

 

I have a full tank

 

Pull the vacumn line off the reg and see if there is fuel there. Could be a torn diaphram otherwise check the hose on the pumps and make sure the clamps are tight.

If one pump is running and the other one isnt, the pressure will not bleed off the non-running pump.

 

When I pull the vacuum line off the regulator there is no change in fuel pressure. There is vacuum.

 

If you crimped the return and fuel pressure didn't rise then it's the feed that's the problem, not the return or the regulator. Look to a failed pump or a disconnected hose.

 

if you dont have a check valve on each fuel pump before they y into one line, then if one pump goes bad it will bleed out of the other one. you need to check all fuses and make sure you didnt blow a ecu fuse. once you get power running to the pumps again. then you need to take the cover off of the tank and see if both pumps are priming. if only one pump is priming and it is getting good voltage and ground then you know you have a bad pump.

 

Ecu fuse is fine c24 in the ecu burst. I'm hoping my problem is what xenocron said a lose or broken hose on the pump

 

didnt you say that your pumps will not prime at the moment? if that is the case i wouldn't even bother opening the tank to pull the pumps until you get that problem fixed...or you could pull the pumps and check them with a extra battery to see if they are functioning before you go digging any deeper

 

Ya I'm not going to do anything until I fix the ecu. I'm supposed the pic up what I need to fix it tomorrow

 

C24 thats odd...I dont even know what that controls off the top of my head.

If everything was wired correctly, grounding out the power wire on the wire pump cant fry anything in the ECU.

Could just be coincidence or you have bigger wiring issues in the car...

PERHAPS the Alt fuse blew...which would severely lower the voltage which caused your fuel pumps to only be able to make 10 psi, and the low voltage caused some other fuse to blow or i dont know what that would make that cap explode in your ECU