Outer Limits 4x4 Board

Is there any way to gain some more Idle adjustment from the fuel pump?
My engine is idling around 820 and thats it for cutting it back using the adjustment screw on the throttle stop.

There should be plenty of adjustment on the pump. Check tappet clearances are ok and also check injection pump timing-look for a scribed line on the flange of the injection pump matching up with a corresponding mark on the pump support bracket. Check the fast idle solenoid isnt holding the idle fast.

Nick

Has the fuel metering screw been played with. If has been screwed in to far the idle will only come down to a certane point. Is it blowing heaps of black smoke.

I have encountered the same problem with mine. After winding the fuel up i can't get the idle to drop any lower than 850rpm. Tappet clearances are all good and pump timing is good to. Any ideas would be great.

Yeah the fuel screw has been wound in but my EGT's are still well within the safe limits and giving it any more fuel will cause the idle to rise.
No it dosent blow any smoke.

So it must be turbo. Well the only way to get the idle to come down futher is to screw the the max screw out a bit,but you will lose power. If you need more fuel delivery at out of the pump to support th boost, but still want it idle at 600 odd you will have to fit a 12mm plunger to the injector pump. That will give you enough fuel to suport 20psi plus. If you do that, make sure you fit a inline low pressure fuel pump(10psi)As the internal low pressure pump in the injector pump will not keep up to the fuel demand. Im guessing to the revs are slow to come back to idle aswel?
Hope this some help to you

marko wrote: So it must be turbo. Well the only way to get the idle to come down futher is to screw the the max screw out a bit,but you will lose power. If you need more fuel delivery at out of the pump to support th boost, but still want it idle at 600 odd you will have to fit a 12mm plunger to the injector pump. That will give you enough fuel to suport 20psi plus. If you do that, make sure you fit a inline low pressure fuel pump(10psi)As the internal low pressure pump in the injector pump will not keep up to the fuel demand. Im guessing to the revs are slow to come back to idle aswel?
Hope this some help to you

Had the same thing with my pump, and revs would not go back to idle at all, allmost 2 turns clockwise (RD28T)

Fitted a 12mm plunger, problem solved and a lot more power

marko wrote: So it must be turbo. Well the only way to get the idle to come down futher is to screw the the max screw out a bit,but you will lose power. If you need more fuel delivery at out of the pump to support th boost, but still want it idle at 600 odd you will have to fit a 12mm plunger to the injector pump. That will give you enough fuel to suport 20psi plus. If you do that, make sure you fit a inline low pressure fuel pump(10psi)As the internal low pressure pump in the injector pump will not keep up to the fuel demand. Im guessing to the revs are slow to come back to idle aswel?
Hope this some help to you

is the 12mm plunger the same as a boost compensator.
what was the price to have one fitted or is it eaisly done.

.

What you are doing by adjust the main fuel screw is increasing fuel over the whole range. Hence no more idle adjustment. It may be fixed simply by grinding a little matal from the throttle lever.

If not, the 12mm plunger is used as it physically can deliver more fuel for any given setting. It is different to a boost compoensater. No its not easy to fit amd does require modifying the pump internals and tuning both on the test bench and the vehicle.

Hope this helps.