TARManiAC

Did the throttle body mod as described on Scoobymods: took the big edge away from the inlet, cut the screws and axle down and filed an angle to the plate. Also ported the inlets to the OE topmount and the port leading to the throttlebody.

Now I can clearly see that mixture has become richer on my AFR meter. It´s the type with 4 little lights and it goes blue (rich) much earlier now (less gas pedal movement). I´ll watch my fuel consumption to see if I get worse mileage. Car is 01 bugeye with EcuTek.

R19KET

Well, somethings gone wrong then. Are you sure the TPS sensore has been re-fitted exactly the same as before ?

Mark.

TARManiAC

No nothing is wrong, car drives just fine and I can feel a little difference for the better in throttle response. It´s just that the mixture seems a little richer now. All sensors and hoses are in the right place.

R19KET

Ok, maybe we look at things a little differently.

If the AFR has gone richer after a mod', it implies that you have either lost air flow, or something hasn't gone back together quite as it should.

I doubt that the mod you have done to the butterfly will have made a major difference either way, so I would suspect the TPS.

However, if you're happy, that's great.

Mark.

TARManiAC

Didn´t even take the TPS off, just un-plugged all connectors and they are one way fit only.

Fuzz

Have you Knife edged the leading edge (when open) of the butterfly itself?

This might go someway to explaining it.
For a given amount of throttle pedal movement you are turning/opening the butterfly, the back edge will move away from the housing, when ground back the actual gap between the butterfly and the housing will now be... hmmm admitting more air hence should be leaner, time for bed I think.. Unless I was right when I started typing.

Will post it anyway.


Andy

Butty

iTrader: (2)

Is it richer at low revs or the whole range?
Something to do with the TPS or throttle cable being adjusted when put back together?
Taking up slack in the cable sharpens initial throttle response, but can't quite see how fuelling has increased because of it?

Nick

TARManiAC

Yes the butterfly throttleplate was slightly knifeedged. No adjustment to throttle cable.

It´s richer with at lower revs.