fordsteve77

Me cabby XR3i (1.6 mfi) is coming out of the body spray shop soon...
and when it does I want to tackle the revs and fuel/air mixture, as it seems to be idling at around 1200-1400 rpm even when warmed up...and running a bit rich/lean

Is this something easy that can be done by my self turning screws to the left or right quarter turn at a time...?

Or go to a local MOT station to get it on Co2 machine and adjust...?

Or a rolling road setup like the RS turbo's go too ( I visted one and got quoted £125 plus vat) ouch....?

Any ides

stevos

If it were me mate I would take it to a garage with experience in mfi and get it set up on a rolling road as they can then check the fueling all the way through the Rev range.

stevieturbo

As Stevo says, take it somewhere with experience of the system

if it's idling at 12-1400rpm, there are more than idle mixture issues.

And CO2 is not checked at MOT, CO is.

Any decent garage will have a gas analyser anyway to confirm any work carried out will pass MOT

fordsteve77

Well 1400rpm might of been a little over the top....

its idling around 1050 rpm to 1200 rpm

would cold start valve be the cultprit stuck open in cold engine position...?

only purchased car end of last year previous owner had medled with the air/fuel mixture and the other mixture screw on air filter/metering box

stevieturbo

It is possible.

fordsteve77

From what I understand extra air causes high idle...
either from the adjustment screw
or
Aux Air Device

So when engine is cold the valve is open, butterfly throttle closed as stationery and idling, adjustment screw letting some air in or not depending on position of screw, so once hot the valve is shut and idle rpm should drop to 800 rpm ish
mine is staying around 1150 - 1200 rpm

Diagram:

Rob_DOHC

iTrader: (4)

Or an air leak.

fordsteve77

ive been all through the air leak problem rob,
(I'm who finally got me xr3i running, rember fuel pump relay, speed sensing module and suppressor etc etc)
is there a way of testing the aux air device...?

Rob_DOHC

iTrader: (4)

Good man, yes the AUX valve is simply on or off iirc on an xr3i, I think its open with 12V across it. Just pull the pipe of and block it temporarily. If the RPM is lower this could indicate that the valve is not fully closing.

I would recommend taking it to someone like Karlos at frienzy performance or if you are prepared to make the journey MSD or even power engineering in middlesex... someone who has historic knowledge of MFI units. Most modern garages are likely to give you a blank stare when they cannot find the OBD plug and many won't even know what MFI is.