I have, over the past couple of years, fitted a new 2.0 blacktop zetec to my car along with the Griffin Power Systems - Total Ford Solutions' kit, which utilises the original Ford throttle body, fuel rail, injectors etc and is run by an Omex 600 ECU.

I have had continual problems with the car running very rich, almost undriveable, hence only about 70 miles since installation. Anyway, nearly at the point of ripping the whole lot out....until

A day or two ago i started the engine and on the plenum chamber there are two pipes (about 5mm ID), one with a thread and a screw, the pipe is cross drilled, apparently this is the idle trim adjustment. The other pipe was for the idle valve i was led to believe. My understanding was that the idle valve is connected and the other end of the valve open to the atmosphere. There is always an incredible suck on this pipe.

I removed the idle valve and taped the opening in the pipe, apart from nearly stalling, if i kept the throttle slightly open the car seems to rev and run much better all round. I took it a short blast with the pipe taped up and it went much much better.
Sorry for the long prelude to my question(s), but...

Should this pipe normally be blocked? What does it mean that it runs much better when blocked? how can i easily adjust my tickover to get a better idle it is far too low at present (probably about 400-500rpm)? Is that adjusted at the ECU via the laptop?

Does this sound normal/what you would expect?

Have you got an idle controle valve fitted and being run by the ecu ?

Imho The idle screw is a bodge and you have no chance of doing it this way. ive welded mine up. There is a small hole in the throttle plate is this bloked ?

Fittesd a similar one to a 2 litre zetec. we attached a rubber pipe to the metal pipe (5mm one) in the other end of the pipe we fitted an air coupling which we drilled and tapped form the side allowing us to insert a bolt, this allowed us to adjust the amount of air entering via this pipe and get the tickover and running spot on

I would get another throttle body and experiment with drilling the hole in the plate and making it bigger.

If it had an air leak it must have run lean and not rich.

If it is the same as my Griifin the hole from the throttle body will be blocked where it bolts to the Griffin manifold.
As you now have no idle valve (which is just a wax stat type) you will find with the map as it is that it may not start from cold now this is removed.
When the engine is cold the idle valve will be open and the ECU via the coolant fuel trim table will increase the fuel, then as the engine warms up the extra fuel is reduced by the ECU, the wax stat idle valve will slowly close on it's own (too early if the same as I was supplied) as it is just a bi-metal strip that heats up with a constant 12v (not controlled by ECU). Now as you have removed the idle valve the fuelling will be out when the engine is cold and not run very well.

Your low idle is either caused by the wrong amount of air (via the idle trim) or the main fuel map needs to be altered around idle.

Thanks for the quick replies.

The only thing i have changed from the original map, on the advice of Martin Griffin, is the overall mbps figure. I honestly cannot remember what it was originally, but he suggested clicking it down 4-5 points. That was done months ago and hasn't been changed. Do you think re-adjusting that might help?

The other drastic thing i did was to take the manifold off and smear silicone very thinly over all the welds in a cheap and nasty attempt at proving the welded joints were all sealed, or not, as the case may be. Obviously it looks terrible and once the engine is running better i will peel it all off again!

The omex 600 ecu will control idle speed either by operating an air bypass or by varying ignition advance/retard. Read the manual for details but mine works this way as I use jenveys. Works well. I assume your throttlebody butterfly can be set to bleed a little air. Idle controls are in the software.