mini not holding revs when i clutch?

[constantdreamer]

It happened the other day and now again all the way home today - when I press the clutch to stop at lights or slow down the revs are falling right off and the engine just cuts out. any suggestions folks?

[antodeco]

Have a look here:

http://www.irishminis.ie/forum/viewtopic.php?f=1&t=4251

Might be something similar!

[constantdreamer]

hi antodeco, I had a read of your issue there...I just checked to see if there was any hoses/pipes not connected, all looks fine. I was having a starting issue a week or so ago where the starter motor didnt seem to be getting enough electricity to turn over the engine. I checked the earth straps and gave them a quick clean and that sorted that problem out. I wonder is it related to whats happening now? Its an mpi so not so i dont have a manual choke etc to aid when driving, tis a bit of a pain starting the car after every slow down or stop. I have no issue eccelerating as far as I know just with the revs falling off when i clutch. i dont know.

[antodeco]

Have you checked the sparks on it to make sure all is ok? Are your lights staying on ok also?

[constantdreamer]

I have checked the sparks no. all else is fine with the car as far as i can tell. doing a search there for similar problems i found a lot of people with this problem in the winter months with carb minis. most found that condensation on the distributor( i think the distributor) was to blame and was fixed by covering it with a glove or something. how do i check the sparks?

[antodeco]

Just make sure all the sparks are connected and not corroded. Did you check the oil in the dashpot, cause that seemed to help mine. Does it happen whether the car is warm and cold?

[constantdreamer]

well it didnt seem too cold today, and it didnt happen the other day when it was freezing out. plugs and leads are all a couple of months old.
other advice i was given was to check the thrust bearings? the person said he had the same issue and his bearings had ''gone so badly that they spun in their housings and wrecked the crank and damaged the block. Cost a lot to put right including a replacement crank - and even then we needed +0.030" thrust bearings to get it OK again after machining the block.'' has me a bit worried now as this is my daily driver! he said to ''Measure the end float on the crank. If it is over 0.012" you need to get that engine out and to pieces straight away for a proper look-see.''

[kona]

If your engine was that bad I think It would be very obvious!

Usually these problems are split pipes or a sensor problem.

[keith]

- snip
other advice i was given was to check the thrust bearings? the person said he had the same issue and his bearings had ''gone so badly that they spun in their housings and wrecked the crank and damaged the block. Cost a lot to put right including a replacement crank - and even then we needed +0.030" thrust bearings to get it OK again after machining the block.'' has me a bit worried now as this is my daily driver! he said to ''Measure the end float on the crank. If it is over 0.012" you need to get that engine out and to pieces straight away for a proper look-see.''

whoa... !! back up there.. on the later Mini's like your MPi, the idle speed is controlled by an "idle air control valve" that bleeds air past the throttle body to control the idle speed. thats what kicks in when you take your foot off the throttle. . . this air valve is in turn controlled by the ECU. I would start by checking working of the air valve. I dont have an MPi, but on the SPi *loads* of poor running/emisisons/idling problems are caused by either faulty or badly connected sensors.. . keep the engine strip down for later!

[constantdreamer]

I'm gona have a closer look at the hoses and such in the morning, I'm praying its something simple as if its an expensive or time consuming problem it couldnt have come at a worse time. i posted this issue on the mini forum website and have only recieved two responses both saying its prob this bearing thing, so i think they just freaked me out,

[constantdreamer]

i go over a hefty amount of stupidly high speed ramps every day and now these excessively bumpy rumble strips up the road that would rattle the teeth out of your head - actually rattled a part of my grill off the car,ha. hopefully somethins just came loose .

[macker]

its more than likely a sensor has gotten clogged or stopped working, nothing too drastic,

having had the thrust bearings let go in an old engine of mine i would say you would definitely know if that had happened!

[woody]

When I read the first post I immeditly thought Thrust washers as what your discribing is exactly the symptons you would get on a carb engine so don't automaticly rule it out as it may cause you a lot more money if you ignore it.Let the engine idle and have somebody press in the clutch as you watch the crankshaft pully. If the pulley moves away from the timing cover then your in trouble. If not then start looking at the injection system.How is your oil pressure when hot at idle?

[MiniMe]

I had a similar problem with my SPI in the past. It turned out that a couple of hoses need replacing:

From the inlet manifold to the fuel trap & from the fuel trap to the ECU. I know the MPI has a different setup but if might be worth taking a look for something similar

[constantdreamer]

I took the filter housing off and had a gander at the pipes and such and all seems ok. The car idled perfectly and when i pressed the clutch the revs didnt move at all . so either the problem has remedied itself or its just an intermittent occurrence. I'll check the crank like Woody suggest (now that i know how to check it,cheers woody) and have a closer look at the sensors for any damage.

[cbyrne]

its the cappillary lines the black pipe from inlet to fuel trap common fault if car is fitted with lcb also check red pipe if these pipe are less than perfect it causes havock with the ecu was ur car spitting or missing/lacking power on full throttle this is the main problem with injection.. hope this helps