Mondeo ST200 fast idle problem

[Kitchski]

Hi, got a 2000/X Mondeo ST200 with a fast idle problem. I've changed the idle valve and gasket for new and the problem is still there.
Weirdly, it's not actually the idle thats the issue, it's more like sticking revs. When you pull up to a junction and dip the clutch and release the throttle, the revs stick at around 3k revs until you become stationary, at which mpoint they slowly drop to the correct idle. Once it's at idle, it stays there, it doesn't hunt around.
It doesn't always do this, sometimes it's fine. It doesn't do it when cold, but after a few mins it can start acting up. This also means it doesn't really do engine braking....it can drive itself along at times!

I was thinking air flow meter, or a leaky hose/duff gasket somewhere, but I'm new to the V6 engine. Anyone got any ideas on where to look? I don't fancy shelling out on a new AFM on the off chance, and working at a Ford dealer as I do, we don't sell many for the V6 at all....or any Ford in fact.

Any help greatly appreciated!

[anonymous-user]

Throttle hang, it can be fixed my inserting a copper end cap with a hole drilled in it in the pipe that is on the back of the UIM, i know some ST200's also suffered from this and the problem the throttle body. Google "throttle hang fix"-that should bring up the info

[monkeyra]

Details here of how to fix it:

http://fordwiki.co.uk/index.php/Throttle_Hang_Fix

[Kitchski]

Magic! Thanks very much, I think that was the problem. I wrapped a couple of cable ties around that pipe to choke it and the problem has pretty much gone! Just need to make a full time fix and I'm away.

Thanks again.

[Kitchski]

Just to update, I've now fixed this using the method described in the link above.

For anyone thinking about doing the mod, I used a blanking plug from the block of a Ka/Fiesta 1.3 SOHC lump. Can't remember the part no, but it was about 80p and looks like a sump plug but without the head of a bolt.
It's a threaded bung about 18mm x 20mm wide. I drilled a 4.5mm hole through the middle, inserted in the pipe, wrapped a jubilee clip around it (don't want it getting sucked in the engine!) and refitted.



Problem instantly cured!