Won't run below 2000rpm when warm

[njhucker]

Can anyone help me with this.
Took my 350 wedge for am MOT Friday, and left it with them for a day.
When I went to pick it up,the next morning, the mechanic said it's not ticking over as smooth as it always has.
Started it up and drove it home, 0.5 mile & it was fine.
Went out in it yerterday afternoon. It started fine from cold, and ran purfectly until the engine was warm, and then would not run at all under 2000 rpm.Above 2000 it runs fine.Let it cool down and it starts and runs again until it gets warm,after about a mile, and then it just dies agian below 2000.
If it wuld not run when cold, or over 2000 revs,then I might have a clue. But this has got me beat.
Any ideas?

[B@man]

Could be an air leak being masked by the cold start system

[RussWood]

Check the temp sensor, I don't remember which of the two at the top-front of the engine it is but when the engine is warm short out the wiring and see if it idles better.

Russ

[grahamw48]

If the underbonnet wiring has been fiddled with, a break could have occurred where a section has become brittle through heat.

This happened on my car after having engine out for clutch replacement.
Mine wouldn't restart when hot, but ok when cold.

[ed_crouch]

Could be the ignition amp. Works OK until it gets hot. Mine did the same. it'd run above about 2K, but would just die at idle. Always restarted, but ran like poo.

[njhucker]

Thanks for the suggestions so far.
Today i have:
checked all the hoses for leaks
cleaned connections on injectors,afm,sensors,throttle pot,additional air valve,ecu.coil.
Never even considered the ignition amplifier, as i thought i it would run at high revs, without misfiring, then it must be fuel.Anyone know if there is a way of testing it without replacing it?

[ed_crouch]

Err, not really. You could have an ignition amplifier swapping BBQ... Basically get a mate round, or go to theirs and swap em over and see if the problem goes with the amp or not.