3rd Gen Fuel Filter and Low Pressure Pump System

Thanks for posting all this info. My question here, is are we chasing the right solution going after the low pressure controller and pump? Maybe it's the only solution?

The #89571-58010 fuel control ECU, while not installed on the Tacoma, is installed on some 2GR-FKS cars. The fuel pump that is paired with that controller ECU in those cars, #23221-31130, is also specified as a replacement pump for the Tacoma (despite a different fuel ECU). Where things become interesting, is that this fuel ECU and pump combo are also utilized with the LS500 twin turbo V35A-FTS and some of the LC500 2UR-GSE engines. This suggests to me, given that the #89571-58010 will work with the Tacoma main ECU, is that our low pressure system should be good for close to 500hp, and the upgrade needs to happen on the high pressure pump and lines. Both of the latter mentioned engines run two high pressure pumps, one on each bank. Since adding a second pump to the Taco would be a very involved mod, perhaps there is a single pump from another application that has more capacity?

 

Honestly you may be on to something here, but I don't think the high pressure system is a simple solution. Here are my thoughts. Mat from OVTune seems to be relying a lot on the Port Injection for additional fueling. Over 7psi we have to upgrade to the Direct Injectors from the LS500. The factory Tacoma direct injection is obviously lacking. That being said, that's probably the best we can do with the factory high pressure system without some major modifications. So I'm guessing he opted to use the Port system to pick up the slack.

This obviously requires upgrading the low pressure pump, which is easier to do. Then of course this comes with replacing the fuel control computer which only seems to exist for the sole purpose of the low pressure pump. He has us using a PWM pump which the factory controller isn't capable of running (factory pump uses 3 positive voltage wires to provide 3 set voltages to vary duty).

In retrospect, if there is a high flow factory pump and controller combo from an already twin turbo'd Toyota....it stands to reason that would be a far easier option. That being said, I think Mat chose the PWM route because it's infinitely more controllable for precise fueling of the port injection. I'm guessing those other options you mentioned use the same simple voltage variations that the Tacoma uses.

Hard to say without some serious research and testing.

 

Also it's important to mention that increased loads on the low pressure fuel pump can easily burn up the tiny little ground running from the fuel pump controller to the fuel pump. It's like 20-22 gauge versus the 14 gauge positive wires. It has to be replaced to run over 10psi boost.

 

Group Buy for an upgraded Port Fuel Rail.

https://www.tacomaworld.com/threads...ed-induction-port-fuel-rail-group-buy.766507/

 

Here are the wiring diagrams for the fuel pump ECUs.

PWM 89571-58010 used on many vehicles including 2GR-FKS


3 step 89570-35280 Tacoma North America only.

 

So looking at the above diagrams, it's easy enough to see they are wired exactly the same. The PWM version of the fuel ECU, when installed in a 2GR-FKS car, has a fuel pressure range that specs out at 28 - 121 PSI. This is a full 36 psi higher than the 3 step Tacoma fuel ECU can produce at its 3rd step max, which is 85 psi. The Tacoma can only supply its fuel pump with a max of 8.8 volts to achieve that number. The PWM fuel ECU can obviously run the stock pump much higher, more voltage available? 11 volts? Again the question arises, can the 2GR-FKS ECU in the Tacoma control the PWM version of the fuel ECU? How much more hp will it support. A flash/tune for the main ECU and a readily available OEM fuel ECU would certainly be a nice clean way to achieve some gains.

 

It would be nice if there was a safe way to test this. I'd like to think that Mat already explored this, but hard to say. Seems like a lot easier option than a problematic custom controller. There must have been a reason. I suppose he may just not have known.

I think the only safe way to test this would be to put the PWM pump and controller on an N/A truck and run it while logging. Do it under boost and you risk blowing your engine. Then maybe swap to an aftermarket PWM pump and test that at the risk of frying the pump.

So here is a picture of the wire harness from the FPC that goes to the pump. You can see the colors match. That being said, the far left white/black is actually cut and replaced by the larger 14ga all black on the right. High load will burn up the tiny w/b ground.



The wiring appears the same at least. My question, why does the PWM also have a 3 wire setup if it's not a 3 step motor?

Here is the modified pump wiring. The colors change once inside the hangar, but it's obviously the same three wire setup from the FPC. For the DW300, you run the three wires together because in the modified FPC, those three wires are also tied together. Realistically you could cut off any two and just use one, but this allows much lower resistance so it's just added protection.



I am curious what the flow on the factory PWM is. If it's greater, how much greater. If it's the same then the only real benefit is that it has more precise fuel control. Then I'd ask, could it run an aftermarket pump without alteration.

Just a lot of unknowns.

 

Regarding the Tacoma ECU running the PWM FPC, I suspect it could without any alteration. It's just two wires running to the FPC so I suspect all the ECU does is send simple information to it. Probably just commands a set pressure based on engine load and lets the FPC logic control the pump independently.

 

The parts diagrams for the new Tundra/LX600 with the twin turbo V35AFTS Engine show a single high pressure pump is now feeding the direct injection. Perhaps this will be another part in the puzzle/attempt to raise the fueling to a higher level.

 

You might be on to something here. I was just talking with someone about this today and we were entertaining the idea of a fuel lobe modification to the cam as a possibility or finding someone to manufacture a high flow pump. I'd be curious to see if this does flow more, or if they compensated some other way. My question is, why didn't they do this in the first place? Why originally 2 pumps but not anymore?

Either way, hoping these rails show soon. Should have shipped this week, but trying hard to be patient....

 

The single high pressure pump is for cost cutting, no doubt. The in tank pump is the same as the Tacoma. The FPC has a new number.

We might need to sacrifice some pumps in order to find out the bore and probably the stroke. The roller lifter for the pump is the same in all, but I'll be surprised if the pump will bolt up to the guide... not an impossible task to adapt, if required.

The cam lobe mod has also crossed my mind, but again, we need to see how much stroke the pump can support. Might also need to look at extra oil supply if we can overdrive it.

 

Might be worth looking in to.

 

LX600/Land Cruiser pump # 23101-79036 is $1532.96. The Tundra pump # 23101-F4010 is $1269.91. Knock 30% off of those numbers for USA sources. Waaaaay cheaper from foreign sources. Ordered.

 

How in the holy hell is it that expensive!? That's a lot of money for something that is an unknown. Hope it works out though.

 

Some additional info that could pertain to overdriving the pump via the cam lobes. The LS500 (two pumps) and the LX600/Land Cruiser (one pump), have three of their four camshafts in common... the fourth camshaft, which is unique to the LX/Land Cruiser, is the right hand exhaust camshaft which drives..... the fuel pump! Hmmmm....

 

So then they use the same camshaft with the extra lobe on the driver side of the LX600/LC (formerly driving the driver pump on the LS500), and block off the hole (or a new cover altogether?), then it sounds like they changed the passenger pump cam with probably a larger lobe on the LX600/LC to presumedly run the pump harder.

That's what I'm hearing at least.

 

New cover sans hole.

Yes, the passenger camshaft is the only one that is different... I can't think of any other reason to change it other than larger lobes to run the pump harder.