And you thought a Supra pump would overrun the stock FPR....

[Chris@Rvengeperformance]

In my humble opinion all you guys running big amp draw pumps on tiny stock wiring are just asking to let the smoke out....

I'm running a hotwire. no way I would run a walbro 416 on stock wires.

[TurboSinceBirth]

Minor rear turbo O ring leak past 25psi, other than that the system is 100% sealed. I used to do the same +1-3, however i couldn't get perfect 14.7 cruising. The way I have it now, -1, -7, 7, 16 allows me to achieve ~ 14.7 when cruising and idle. If I do the typical ACCEl setup I run 3, -7, 7, 1. This puts me in the 12 &13's when running around on the interstate. Not acceptable IMO.

Something doesn't sound right mechanically or electrically but I guess if it works. I'd be curious what your fuel trims are.

[mb3000]

I can try to get a log when the snow clears up..

[RealMcCoy]

I'm running the walbro 416 on the stock fpr (new one though) and didn't even notice any tuning issues. That is with 1050 cc injectors on pump 93 for a while. If you have any resolution with your tuning device it doesn't matter a whole lot.

It does depend on the tuning device... This car in particular is using an SAFC. (not exactly the pinnacle of sophistication) Typically quite easy to tune with 450's or 550's due to the fact you're just using the stock map times a multiplier, and tweaking the areas that the load cells get messed up... A little overrun is no big deal to tune around, people have been doing it for years, but when taken to an extreme, you're trying to reinvent the wheel with a tuning device that isn't even load based...

The one thing that bugged me about this particular case, was that I was having to pull so much fuel at idle, that it dropped the MAFS Hz below the 31 Hz threshold. when that happens, you can pull all the fuel you want, the ECU is still going to use 31 hz... Pull 25%, 31 hz, pull 40%, still 31 hz... At that point you're relying on the trims to pull enough fuel to keep the mixture correct, so you can forget getting them anywhere near 100. After fixing the fuel pressure, this car was running 37-43 hz, and the fuel trims were hovering around 100 with the expected correction.

Running the pump at lower voltage may help the pump life though. I'm just not willing to hackup the stock fuel system unless it was absolutely necessary.

No hacking necessary... While I typically remove the fuel pump relay and a couple inches of the harness(saved for future re-install if it ever needs to go back to stock) It could easily be done at the fuel pump relay connector, with no cutting of the harness at all.

Really, why? Stock wiring is dropping only 1 volt or so. Stock wiring is 16 awg which is .004 ohms per foot. Yes you can drop a couple of watts of power across the wire but that's over many feet.

While I do prefer a larger wire, 0 voltage drop, and having the pumps full capability available, the wire isn't my concern... It's the connectors that are likely to turn to bacon long before the wires fail...

[Chris@Rvengeperformance]

It does depend on the tuning device... This car in particular is using an SAFC. (not exactly the pinnacle of sophistication) Typically quite easy to tune with 450's or 550's due to the fact you're just using the stock map times a multiplier, and tweaking the areas that the load cells get messed up... A little overrun is no big deal to tune around, people have been doing it for years, but when taken to an extreme, you're trying to reinvent the wheel with a tuning device that isn't even load based...

The one thing that bugged me about this particular case, was that I was having to pull so much fuel at idle, that it dropped the MAFS Hz below the 31 Hz threshold. when that happens, you can pull all the fuel you want, the ECU is still going to use 31 hz... Pull 25%, 31 hz, pull 40%, still 31 hz... At that point you're relying on the trims to pull enough fuel to keep the mixture correct, so you can forget getting them anywhere near 100. After fixing the fuel pressure, this car was running 37-43 hz, and the fuel trims were hovering around 100 with the expected correction.



No hacking necessary... While I typically remove the fuel pump relay and a couple inches of the harness(saved for future re-install if it ever needs to go back to stock) It could easily be done at the fuel pump relay connector, with no cutting of the harness at all.



While I do prefer a larger wire, 0 voltage drop, and having the pumps full capability available, the wire isn't my concern... It's the connectors that are likely to turn to bacon long before the wires fail...

Agreed, I ran into similar issues running the evo 560 cc injectors with a SAFC.

By hacking I was referring to some who would want to run an aftermarket FPR and start using non stock fuel lines. The wireing doesn't concern me if carefully done.

Don't get me wrong I am interested in your solution, it is just easy for the uninformed to draw the conclusion that you MUST have an aftermarket FPR or other method to run these big pumps.