What’s up everyone,
So I went tuning my car and my hardwired walbero 450 is running out of pump at 540 whp dynojet. I’ve seen a lot of people run hardwired 450 to 600+ whp dynojet. Even my tuner said that it’s weird how mine runs out of steam at higher RPm. Any idea of what it could be? I have a built 2.4 with FP black and all the bells and whistles s2 cams, 2150 injectors, fuel rail, intake and exhaust mani. I’m not really sure what’s goinf on. And FYI the pump has maybe 6k miles on it not that old I also got a new sock for it before the install. I did check the part number it is the high flowing one. Any idea what could cause a hardwired pump to run out at high RPM? I couldent finish my tune due to low flowing pump.

Any help would be appreciate it.

Thanks.

 

How was it rewired? Which kit and what wire sizes were used?

 

It's because you've made the same mistakes as everyone else and you're out flowing the regulator.

 

Doesn't that only affect idle?

 

I got the STM kit. Ran it from the battery to the positive side of the pump. And the use the factory harness to attach the relay to the pump.

 

I have a aromotive regulator which is set at 43.5 psi base idle

 

Here is where I would start.
Measure Voltage at the pump under WOT.
Also Fuel pressure at WOT.
Check grounds and the harness for issues.

 

You should not be maxing out that pump at that level.

I run the HP 450 and I am just now dropping fuel pressure past 8,000 rpm (approx 6psi drop) at 570whp Mustang, 640whp Dynojet. OEM fuel rail, OEM FPR, OEM feed and return lines.

I have my 450 in a surge tank, with a torqbyte fuel controller and 10AWG wiring.

PS. Mods, why do you keep deleting my posts? Please PM me with your concerns.

 

What the voltage suppose to be? 14.7?

 

You should get as close to 14.0 as possible (average voltage from alternator). It should get up to 14.2V under WOT. Maybe as high as 14.5V but nothing more. Most fuel pump tests are at 13.5V, which should be attainable from any car.

 

Did you install in parallel to your factory wiring? And what's the wire size from battery to pin 30?

 

By base, I assume with vacuum hose disconnected to fpr. So once you connect to intake manifold, pressure drops to mid to high 30s.

 

33 PSI with vac , idling.

That's what you had before you modded it.

 

Used a 10 gauge wire that came with STM rewire kit. Ran it from the battery to the positive side of the pump then use the factory harness to trigger the relay and seat bracket for negative.

 

Yes. With vacuum hose disconnected set the pressure to 43.5 and when I hook up the vacuum I get 40psi if pressure.