13 replies to this topic

[GarethP]

On my recent journey from Luxembourg to London, at the very end, just pullling into central London, my mini's throttle started sticking - revs would hold at around 2500rpm and sometimes climb from there to around 4000rpm.

The pedal travel is fine, and I cannot pull the pedal up from underneath.

Had a look at the throttle cable, and it had come loose from it's routing clip, but putting this back didn't change things. Had the airbox off yesterday, and adjusted it a bit, and it seems to have helped, but on a 45min blast this morning it did hold at 2000rpm on 2 occasions... :?

What's the next thing to do? WD40 over the springs and into the cable housing?

Does anyone have a pic of an 1999 mpi throttle cable routing so that I can check that isn't an issue?

Many thanks

[Purple Tom]

my mate had this problem (tonyminiman - come help!) with his 2000 MPi. He replaced the throttle cable and made sure all the linkages were free, and it still did it.

He took it to Surf Blue garage in Notts and Geoff reset the ECU (can't remember how, something about pumping the throttle ten times in ten seconds with the ignition on I think), and it did the trick, hasn't stuck since!

I don't know if thats any help, but it might give another thing to try.

[Guess-Works.com]

Never grease or oil an accelerator cable, it will attract dust and clog... They are dry fit and should remain that way.

[GarethP]

thx for that - will steer clear with the wd40!!

have tried the throttle pump ecu reset - no difference.

[miniman5]

ptu some oil in the dash pot, use automitic transmission fluid.

[marc]

Do mpi's have a throttle body like the rover k series engine? They had problems with the throttle sticking, they changed the design from a plastic housing to a metal housing.

The pumping the pedal trick resets the throttle position sensor.

[P91MER]

ptu some oil in the dash pot, use automitic transmission fluid.

Its an injection, no dash pot!!!


If it does it, and u cannot pull the throttle back manually it isMost likely to be the throttle potentionmetre, or the stepper motor on the injection unit.. potentionmetre is found on the left hand side of the throttle body, get it off, clean it with some carb cleaner or something.. stepper motor is found under the throttle sensor, black thing, with big blue connector on it.

Rich

[GarethP]

cool - thx.

it gets more frequent as the car gets warmer, and actually pulls the revs down into a stall occasionally, especially when manouvering on a light throttle...

[miniman5]

sorry, didnt read all the post!, it could be bad machening.

[Jammy]

Bad machining of what?

[GarethP]

took IAC valve off, and was a bit black at the tip - and it all just wiped off. refitted, took for a spin, and no discernable difference - didn't grease it though - is this a necessity???

so, maybe it is indeed a warped throttle body...
had a look, and moved the butterfly with my finger, and there doesn't seem to be any restriction on the movement whatsoever...

played up really badly this morning on the way to work, and took the airbox off while the engine was still running and the revs were stuck at around 1200rpm - there was a constant sucking of air noise, which I presume is the throttle body letting in air - pushing down on the butterfly wouldn't close it any further though??

excuse ignorance here: on the right inner rear wall of the throttle body, there is a hole that goes through to a rubber tube coming out. This sucks in air, and when covered the engine revs die to a stall. Is this part of the idle mechanism??

help help help!! not easy to get to a mini friendly garage here in luxembourg to get these things looked at.

thx.

[P91MER]

That rubber pipe connects to the idle air control valve, or stepper motor, and should be open/close as to what the tick over should be,.

Try the throttle potentiometre, its held on by 2 hex screws, only a 5 minute job to get off, clean with some carb cleaner (or i use WD40, but don't tell the docs) also clean the connectors aswel,,


If it is non of the above, then maybe warped throttle body, but i have never experienced one of these, only a knackard IAC, and throttle potentionmetre, and the problems sound exately the same as urs.

[GarethP]

will have a go with potentionmetre - if not could be that the IAC valve is knackered I suppose...

many thanks.

[GarethP]

UPDATE: Have now taken the throttle position sensor off as well, and wiped it down - replaced and the problem is now 80% better...
Is going out and buying some carb cleaner (what's an equivalent?) and properly cleaning it going to help??
Should the tps be greased as well before replacing??
Thanks.