E16se Tuning

[paul91085]

Fitted my piper 285 cam but is very lumpy below 3500 RPM, could do with adjusting the fuelling so it runs well enough to get to the rolling road on monday. Questions is, which way do i turn the tuning screw on the air mass meter to richen it or weaken it?

Also, since ive put the engine back together i get a whineing noise that gets louder and quiter depending on engine revs. Does anyone know what this maybe? Ive changed water pump, head gasket but thats it and it didnt do it before.

[Adam]

That screw only adjusts the idle mix.
What exactly are you having "setup" on the RR? as theres not much adjustability on the std engine.

Whining could be the alternator belt, or cambelt too tight.....

[burgo]

i thought there was a mixture screw on the afm adam?? it is covered i think tho

[meritlover]

the screw is just idle CO

by adjusting it open, your bypassing the flowmeter flap at idle allowing more air to travel into the engine (unaccounted for by the flow meter) so the mixture weakens.

this has little effect once the flapper starts to open as there is least resistance for air going round the flap than there is going round the needle valve (screw)


it might help if you richen it (screw it in) as the high overlap will be making the air carry right out the exhaust with the fuel in it, causing the mixture to be weak and give a poor idle. perhaps you should try retarding your cam timing or setting up as per the manufacturers instructions. or if you have already done this, it will be necessary to set your base ign timing again as it will move with your cam timing.

happy Sunday!!

[paul91085]

Reason for taking the car to rr is that I picked up a vernier for cheap, so fitted that and wanted to get it all timed up properly. Its gonna be my daily drive for a while so wanna know its running as best it can or as near as. I want to get the basics running ok before i take it for rr, but still cant get it to idle well and it has a misfire at low revs wen accelerating gently or hard, but get to 3200/3500 revs and it picks up great and keeps on going and going.

Any got any ideas?

[Adam]

i thought there was a mixture screw on the afm adam?? it is covered i think tho
It is, As ML said, it only adjusts idle mix :)

[burgo]

in that case could you adjust the fueling by adjusting the tension on the spring for the afm flap?