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MG MGF Technical - Clutch Judder

There are quite a few threads in the archive relating to clutch judder on TF's, but I cannot find any definitive solution.
I am currently experiencing this on an '05 TF and so far the dealer has changed plugs (which made it go away for about 3 days) and updated the MEMS software to the most recent spec. It is currently due to go back into the MGR dealer next week for some more extensive diagnostics, so was just interested if there is a single answer to this problem.
N Raffan

I too have a 05 TF with what feels a bit like clutch judder, it has only started recently (last 6 months) and only when the engine is cold. I recall a thread in the archives, someone having this problem well before I did. Clutch judder can often be due to surface rust or oil contamination of the flywheel, but the cure, in the above case, was to update the MEMS software to the latest standard. I haven’t got mine sorted yet, ‘cos it doesn’t bother me too much yet, but I’m interested to know what your solution is. I guess this must be fairly common?
MG Mike

I had/have the same problem and had the software update - fixed it for a couple of days, then it came back. What I have discovered is that if you turn the ignition on (to position 2) you'll hear a whining noise. Sounds like either the fuel pump or a stepper motor resetting and lasts about 2 seconds. If you wait until this has stopped before starting the engine the judder is much less severe and in most cases gone completely. I have no idea what this is or why it might make a difference but it does for me - and it's free to try!

Cheers,
Tim
Tim Jenner

Very interesting Tim, I understand that there is an air control valve (bypass air actuator) used for idle-speed control, this is only in *real* open use when the engine is cold, rich fuel but more air too, (explains my symptoms). These valves are notoriously bad, being of an open loop type control. I.e. at power on the ECU actuates the valve more than fully one way, to ensure that it ‘hits-the-stop’, the assumption is then it has indexed and starts to control, but with no positional feedback from the valve, poor design but cheep! I’ll try your suggestion this week and report back! Good spot, thank you!
MG Mike

Now there is a thread title to wake me and Tim up everytime! I have had pretty bad problems with this from practically new on our 2003 TF135 and the last service was a ECU software upgrade. Again, this cured it for a while but it still does it occasionally - worse case is a really hot cycle then getting very cold, it can be a right pig at the next start for the first few pullaways then. I will try Tim's latest "mod" now. I had a couple of shudders at start-up last week on hols so on the way home on Saturday in the really hot conditions got the car as hot as I could with a bit of right foot for the last half hour and then left it to the next morning - guess what...nothing, right as rain! The only difference to normal was the high overnight temps. It must be fuelling/cold start ecu mapping/idle valve thingie. It is not helped by the either 1k or 1.5k revs setup and my driving style. I usually drive my 9-5 which is unstallable and always struggle going back to the F with this nothing or all management. Cheers Tim, let's give your idea a go!
Tony

Fingers crossed! I agree it's definitely something to do with temperatures and cold start. The worst case I've found is when I leave work in the evening - my morning drive is a 70mph blat up the A3 followed by parking up within a few minutes so this fits with Tony's description too. Let us know how you get on!

Cheers,
Tim
Tim Jenner

Mine is always worst after it has been left for a few hours. However it can also (usually, but not always) be demonstrated by slipping the clutch in first gear without touching the throttle pedal. This will usually give a relatively mild judder.
Tim, I think the noise you hear is just the fuel pump priming the injection system, so I doubt that that would affect it.
Regards,
Neil
N Raffan

Anyone had a chance to try this yet? Just curious to see if it's made any difference!

Cheers,
Tim
Tim Jenner

All I have managed to do with the TF since we got back is wash it as SWMBO has pinched the keys back.

We bought it, She drives it, I wash it!!!!
Tony

Tony your in the same boat as me went to france Laon car rally great shine great weekend no rain pure sun get back to blighty and rain what did she do drive through the mud pudles. (who cleaned the car me)
Graham

Update on the judder problem. The car was in at the (ex) MGR dealer yesterday and they changed the plugs and leads. They told me that the at the previous attempt to cure the fault the (non MGR) garage had fitted 'cheap' spark plugs and not changed the leads. So far so good, no hint of judder. However it will be a few days yet before I can say whether the fault is cured since the car ran OK for about 3 days when it had the 'cheap' plugs fitted.

Neil
N Raffan

My update – So far this week I’ve switched the ignition on, waited about 3 to 4 seconds, and started the engine, waited about 5 seconds with the engine running before driving off. I’ve not noticed any significant judder so Tim’s advice seems to work. I have noticed, however, that during the initial idling, the idle revs modulate at about the same frequency as the ‘judder’. From the initial starting, this judder does drop-off in a few seconds, depending on the engine temperature, noted this week as the outside temperature has varied from warm to cool. I assume that if I drove off immediately the judder would be felt when pulling away. And during this ‘modulation’ the rev-counter doesn’t move in sympathy. My TF has only done 11K miles so the plugs leads etc should all be in good order.
MG Mike

Mine's done just over 20k so the plugs could be due - I've never trusted the MGR guidance that they don't nee doing for 60k (or whatever it is). Would be interested in how you get on, Neil - and also what the "cheap" plugs were and what they were replaced with. Have been looking at NGK Iridium plugs, BKR6EIX-11 - but at ten quid each they're not cheap, especially if I then have to add another 30 or so for the HT leads...

Cheers,
Tim
Tim Jenner

Mike, my TF has only done 9K. I'm sure that it is also significant that the MEMS was way out of date on mine - don't know why as its an '05 car.
Fortunately (for me) the work has all been carried out by the dealer that supplied the vehicle to me. Unfortunately (for you, Tim) it means I have no idea which plugs were fitted/are fitted as I have not seen any invoices. I can only assume that the MGR dealer will now have fitted genuine MGR plugs & leads.

Neil
N Raffan

My thoughts may be irrelavent, but here goes! I think when cold the petrol injection pump runs until up to pressure. When hot after short stops it maintains pressure and you don't hear it working.
When cold, the ECU needs a few seconds to zero everything, work out whats what, and then fire up when activated. If you fire up straight away it doesn't have time to work all this out immediately, and so there is a few minutes of "choke out running" until it sorts itself out.
I normally wait for the pump to stop running, fire it up, wait a few seconds for everything to circulate, oil etc, and then drive off. I have had the "judders" if you speed the process up.
Clutch judder is something else, probably rare these days, and not what we're really talking about here?
The ECU in the F/TF is after all from basically pre 1989 with limited upgrades along the way. I bet a more modern ECU would eliminate any cold start fuelling problems?
Just my thoughts.
Jerry Herbert

Your thoughts pretty much tally with mine, Jerry - and my feeling is that the initial overfuelling causes rough running which is made worse by ignition components which are past their best. Past experience with a Rover Metro leads me to think the K series engine's pretty good at hiding worn out ignition parts - on that car it suddenly refused to start with no prior problems at all. Turned out that the plugs, leads, cap and rotor arm were 80,000 miles old - one plug and the cap disintegrated when I took them off! Will be very interested in whether the new leads provide a longer term fix, Neil!

Cheers,
Tim
Tim Jenner

One week on from having new plugs and leads and the car has been fine. However, just this morning it showed a very mild sign of juddering. Just hope that is not the first signs of a return of the problem!
N Raffan

This thread was discussed between 15/06/2006 and 01/07/2006

MG MGF Technical index

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