Different air flow bank 1 vs Bank 2 - AEM 02 FB

[cyruss]

After rebuilding the engine and installed a AEM standalone, I have a big difference of fuel needed to be injected between the two bank.

On the driver side I need to add around 10% of fuel to have the same AFR than on the passager side.

Is that normal du to the design of the stock intake manifold ?

Thanks for your feedback.

[XSnake]

Do you have new 02 sensors?

[cyruss]

Yes Wideband with the AEM standalone package.

At first the 02 sensor on the driver side was not correctly wire on the AEM factory harness. Then after test and rewiring, the wiring was ok, but the Sensor was always show lean. Then I add fuel and notice the sensor start reading correct AFR.

But if I remove added fuel on the driver side I notice the engine is not running good at all. So I think it's really a mechanical thing than electrical.

[XSnake]

you may have a bad injector

[cyruss]

I change all of injectors from bank 1 to bank 2... and clean them at the same time ... same, always same driver side lean. (injectors are injector dynamics 750 btw)

[XSnake]

I change all of injectors from bank 1 to bank 2... and clean them at the same time ... same, always same driver side lean. (injectors are injector dynamics 750 btw)

What pump are you running? IIRC the fuel comes in the manifold on the pass side. Might be a little lower pressure on the drivers side if the pump isn't keeping up with demands

[cyruss]

2011 10 - 1.jpg
2011 08 - 4.jpg
2011 10 - 3.jpg
2011 08 - 2.jpg

[cyruss]

As the 3rd pump is not powered maybe there is a "leak" of pressure there, so the fuel without enough pressure goes more on the passanger side than driver side ... I will try to plug the 3rd pump ...

[cyruss]

What pump are you running? IIRC the fuel comes in the manifold on the pass side. Might be a little lower pressure on the drivers side if the pump isn't keeping up with demands

You may have THE point.

Before When I put ingnition, I got the Fuel pressure correct and the nail was not moving at all. Since a few months (and since the notice the problem of AFR) when I put the key on ignition, the fuel pressure goes up, then drop a bit and I cannot have to prefect until I start.

So maybe I have a loss of fuel pressure, and that could be because of the 3rd pump which is not running, maybe the fuel is going back to the tank though it.

I will check that and try to start with the 3 pump running at the same time !

Thanks for the lead !

[cyruss]

could be a idea. I'm running 2 walbro 255l/hr, mounted on a 3 fuel pump hanger. One fuel pump is not used right now.

all the fuel goes on a AN10 fuel filter, then a "Y" with 2 AN8 out for each bank. After the fuel rail, exit AN6 on the fuel regulator, and AN6 exit to go back to the tank. All Aeromotive products.

At the begining this fuel system was brought as I my go S/C or TT in the futur so that's why it's a bit big for my N/A application right now.

[XSnake]

could be a idea. I'm running 2 walbro 255l/hr, mounted on a 3 fuel pump hanger. One fuel pump is not used right now.

all the fuel goes on a AN10 fuel filter, then a "Y" with 2 AN8 out for each bank. After the fuel rail, exit AN6 on the fuel regulator, and AN6 exit to go back to the tank. All Aeromotive products.

At the begining this fuel system was brought as I my go S/C or TT in the futur so that's why it's a bit big for my N/A application right now.

Your FPR is after the fuel goes through the lines? am I understanding that right?

[XSnake]

put a gauge on your FPR and watch what its doing or watch it on the laptop. Looks like you have a sensor in it for FP

[cyruss]

Pressure is ok all the way, but how does it work if there is a different pressure on each fuel rail/bank ?

if I have 40PSI on bank 1 and 46PSI on banck 2 ... does the sensor will show 43PSI (correct).. ?

[cyruss]

yes. check the pictures on the upper post. It goes like this

D. side ==== Fuel rail ---|
...................................FPR ---- line to fuel tank
P. side ==== Fuel rail ---|

[Bugman Jeff]

Maybe a little obvious, but you don't have any exhaust leaks do you? An exhaust leak can suck in air that will make the O2 on that side read lean.

[cyruss]

I was thinking also but I check and not leak. A very small one but it's 20cm after the sensor ...

And also, when I remove the fuel trim by cylinder (to add on the driver side) the engine is not running good ... that's why I guess it's mechanical.

Some of you have some tune for there N/A car, does it have any fuel trim by bank or cylinder ?