New Fuel Pump for the 4AGZE

[Gtsi-R]

can that be an awnser for the little dip in my air fuel ratio?

I do not do not think so, because of the ok ratio at 7K RPM

[Ivan141]

What dip? You mean the bit around 6,5k rpm where it goes pig-rich?
I think you are reading the graph incorrectly, it's air-to-fuel and not fuel-to-air, so a lower number indicates a richer mixture.
You might be loosing power due to this judging by the dip in the power curve, although 12:1 is not extreme for a boosted car.

[Uzelac]

It really looks like going 12 AFR instead of 13 costs him few HP. Hmm, interesting!
Nevertheless, you have more than enough fuel Gtsi-R.

[NoHachi]

Below peak torque: more fuel == more power/torques
Above peak torque: less fuel == more power/torques... well.. until it goes boom.

The number of 190l/h seems very high. 200hp is just 63l/h worth of fuel. Add 20% for charge cooling/boost, and another 30% bypass flow and that's still shy of 100 l/h. Could imagine a tired old pump ending up at that number..or maybe a system with clogged injectors/filters etc, but that shouldn't harm hp. Maybe its rated 125l/h at a lower system pressure?

[heshan]

Guys, I havent replaced my fuel filter either? You think there's a limitation on that too?

I still have the one from my old engine.. 20 + yrs old...

[allencr]

heshan Wrote:Guys, I havent replaced my fuel filter either? You think there's a limitation on that too? (

Very unlikely. Can it redline 3rd without the plugs looking blistered, then it is OK, 'it' being the entire fuel system. Excess pump capacity will do nothing for performance and can hurt it, especially at idle, if it's overwhelming the capacity of the FPRegulator return.

[ash16valve]

allencr Wrote:

heshan Wrote:Guys, I havent replaced my fuel filter either? You think there's a limitation on that too? (

Very unlikely. Can it redline 3rd without the plugs looking blistered, then it is OK, 'it' being the entire fuel system. Excess pump capacity will do nothing for performance and can hurt it, especially at idle, if it's overwhelming the capacity of the FPRegulator return.

I agree with Allencr, depending if you are going the turbo route in the future then Yes the Wallboro pump will be necessary but if you are going to keep it SC then No leave the pump and change the petrol filter.

[heshan]

hmm.. so you're saying DONT put the pump ON? Damn almost put it on as it was told to be OK to put on..

On the Fuel Filter, wouldn't that also be a bottleneck for flow? Is there a good filter for this or just the stock one is fine?

How's the Bosch Filter made for MR2? would fit this right?

[NoHachi]

Just slap it on and see what happens You'll be fine. Fuel filter->almost anything will fit..the MR2 will most likely be fine and they cost peanuts.

[heshan]

Ya I think I might.. also mechanic said it might be sufficient to clean the old filter and put it back on..

thanks guys for all your input .. this is great!!