Out Of Fuel

[greddy_skyline]

Hi guys and girls,

Im having some problems with my fuel system. My car on the dyno is making 300 RWKW but if the workshop tunes it more than that the car physically runs out of fuel. The fuel system spec's as follows

- New areomotive stealth 340 intank pump.

- Reconed 8 (something) cc injectors.

- New fuel filter.

- Stock fuel pressure reg.

The fuel pump has been wired up right using 10g wire and a 30A relay as per instructions and has been install and place on the bracket so it reachs bottom of the tank.

I called the guys that sells the pumps and said that they are happy to test and replace if needed but he commented that they haven't heard of a faulty one nor did he say its not possible and that that pump should be ok for the job. But im in the process of elimination. But i want to know how much can the stock fuel reg make?

Any help would be great!

Many thanks

[Hanaldo]

I've seen the stock fuel reg make well over 300kw before. My tuner said he uses the stock fuel reg in most applications if he can, and he tunes some serious cars. So unless there is a problem there, I doubt it is your reg. What duty cycle are the injectors being run at?

I'd be looking at the pump.

[scotty nm35]

Its more likely the injectors, perhaps the spray pattern is crap or they are gummed up? Get them flow tested when they do the pump test...

[greddy_skyline]

Im not sure what duty cycle they are at. But they also told me that i cant run it over 5000rpm otherwise it will be leaning out.

[greddy_skyline]

The injectors have just been tested and reconed.

[Hanaldo]

And your tuner can't tell what the issue is?

[R31Nismoid]

^ same thing i was thinking.

Either way it won't be the stock reg causing a problem unless it's stuffed as they will hold a lot more with correctly sized injectors... It can be checked in a few seconds with a pressure gauge (assuming they have done that already given how easy it is).

[GTSBoy]

Here's the funny thing.....because the stock fuel reg is in the return path to the tank, it can NEVER BE A LIMITATION on the max fuel flow through the injectors. Because at max demand, the regulator is in fact closed, no fuel is flowing back to the tank, it's all going through the injectors.

Did anyone hook up a fuel pressure guage while tuning this car?

[greddy_skyline]

I have the pump out for testing on monday, so keep you updated.

[greddy_skyline]

Sorry for the late reply.

Found the issue. When the auto electrician place done the wiring loom they didn't solder one of the connections right. So we re-soldered it and all if good now!

thanks guys for all your post.

[mico]

so fuel pump wiring ?? was your pump direct wired to battery ?

[KiwiRS4T]

so fuel pump wiring ?? was your pump direct wired to battery ?

"The fuel pump has been wired up right using 10g wire and a 30A relay as per instructions and has been install and place on the bracket so it reachs bottom of the tank."

[mico]

and ?? whats that got to do with anything ? did u just learn to copy and paste ?

[Dajae]

I can see where you're heading with that.. He doesn't actually say where it's wired up to. As far as we know, the instructions part of - "The fuel pump has been wired up right using 10g wire and a 30A relay as per instructions" - could be completely wrong.

OP, did your tuner end up giving you feedback on your IDC/flow test results?

[greddy_skyline]

It was all set up right. The wiring required power from battery to relay then a signal wire to the relay but the negative wire from the pump need to go to the body instead of the returning to the wiring loom. But one of the plug that go into the relay wasn't soldered right so we re-soldered it and all is good now. If you would like to see the wiring instructions just Google the pump (stated in my first post).