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I got a little problem here.

First thing first. The car worked great with the AEM ecu untill I changed my fuel lines.

I got good readings from my 3.5 AEM MAP and my AEM IAT sensor.

But when I got from -AN4 to -AN6 fuel lines on the feed side I had to tur the pressure up. It is at 3 bar. Still -AN4 on the fuel return line.

SO when I unplug the TPS sensor i can start it and it idles good(rich), but if I contect the TPS back in the car stops, or if I touch the throttle, the car stops. Like it's drowning or something.

Is there anything I can do just to get it going to my tuner?

Spec:

RB25det

750cc injector

255 fuel pump

AEM Series II

3.5 MAP AEM

IAT AEM sensor

I have tried to set the fuel pressure down. But no luck. I had to turn the fuel pressure up because it was under 1bar.

But it runs ok when tps is unpluged.. and when the tps is unpluged the tps has 100%.

I know it is 100% because it has no volts, but i gues there should be something I could adjust to get it moving at least.

I adjusted the pressure without the vac line. And then connected it back on. I gues there is something I hvae to to in the AEM software. But I don't really know all the settings there.

And it would be great to have it going before I got it to mapping.

I think that -AN4 lines is a bit small. So thats why i wanted to go one size up. It was just to make sure it got enough gogojuice.

I will play with the software tomorrow and see what I can do by myself.

But it should not be a problem using smaller returnline that feedline, should it?

It depends on pump flow and pressure.

I run two 6an feed lines, one per rail, and one 6an return. This isn't an issue for me as the twin Walbro 255's don't flow a huge amount of fuel. With a larger pump pressure would rise, (at idle mainly, as the injectors aren't using much fuel.)

A way around this is to reduce the power to the pump at low demand using a pwm output controller. If you can slow the pumps down enough that the return doesn't max out, and the pressure is stable, and tune it into the map somehow you will be able to run a massive pump off a small return. I have a 1500hp Fuel lab to fit into my setup for this very reason, they have a built in PWM controller which can be speed controlled by any ecu.

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