Engine Idle and 3k rpm

Hi all,

and happy new year!

Took the Volvo 740 Estate 2ltr 1990 (G reg in the UK)for it's MOT last weekend. Suffice to say, it sailed through with no problems at all.

The day before the MOT the engine idle was a bit rough to the extent that it would drop to around 300rpm(ish) and then stall. A quick squirt of carb cleaner and a cloud of smoke later, the idle leveled at 750-800rpm(ish), the power came back and the white smoke that was coming out of the exhaust cleared.

Now I have been left with an interesting problem. If I keep the revs below

3000rpm the engine will return to an idle of 750-800rpm. If I go above 3000rpm the engine will idle at 1500 rpm and stay the same until I turn the engine off. This is making breaking very interesting indeed.

I've tried resetting the ECU by disconnecting the battery for an hour or so but this hasn't helped.

Could any one offer any advice?

Many thanks,

Richard

Reply to
Ricardo
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Throttle switch is knackered?

Tim..

Reply to
Tim (remove obvious)

IRT "Throttle switch is knackered?"

Oh! Is that going to be expensive? Also, could a reletive amature fix it?

Thanks,

Richard

"Tim (remove obvious)" wrote in message news:dq8th5$7d1$ snipped-for-privacy@nwrdmz02.dmz.ncs.ea.ibs-infra.bt.com...

Reply to
Ricardo

You dont mention which engine you have, we ought to start there, but yes, the TPS is a bolt-on + wiring plug job.

However, i would want to test it first to make sure that is the culprit.

tim..

Reply to
Tim (remove obvious)

The engine is a B200F

Thanks for the tip. I'll let you know how I get on.

Richard

"Tim (remove obvious)" wrote in message news:dq9b0k$5v0$ snipped-for-privacy@nwrdmz01.dmz.ncs.ea.ibs-infra.bt.com...

Reply to
Ricardo

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