i’m new into the s1 exige, but previously had a 340 that was fairly tuned with a DTM ECU. now the s1 is standard and from cold warms up fine and no problems. if i turn the car off and then back on, whenever i use the clutch the revs flare drastically to 3k, and then are slow to drop back to idle. never had this problem with the 340. it’s almost as if the auto choke is on a time set rather than a temp set?? is this correct?
Describe in a bit more detail how the engine speed surges to 3k when you depress the clutch?
Mine had loads of problems with idling and engine racing when braking - totally mad – ended up being the inlet air control valve - was swinging about off its mounting under the air box. It was just hanging on it’s hoses. They also get muck in the valve which needs cleaning out once in a blue moon. Other idling problems I have had were due to corrossion on plugs at distributor end of spark plug leads - change to magnecor leads sorts all the spark plug lead problems in one. Good luck with it.
Other idling problems I have had were due to corrossion on plugs at distributor end of spark plug leads - change to magnecor leads sorts all the spark plug lead problems in one.
If it was a corrosion issue then a change to almost anything new would have been an improvement, wouldn’t it?
Magnecor may be good leads but they don’t do anything standard ones don’t do.
Point taken but…
I feel the standard rubber leads are a weak link - the plugs at each end are not as good as those on Magnecor leads - being that they have to work close to a hot engine and the engine bay is not exactly rain proof. I think you have to give the feed to the plugs the best chance of working you can – for my money Magecors are the best.
well, if i start the car from cold, it will flare to 2k for a little and then fairly quickly go to 1.5k then settle on 1.25k. in traffic before it’s completely warm it might flare up to 2k when you put the clutch in coming to a traffic light, but then settle to 1.25 quickly.
if you then go to the petrol station for example, when the car is restarted, as soon as the clutch is pressed, the revs will flare to 3k, and hold for a few seconds before dropping to 1.5 then 1.25k. then if you are maneouvering, every time the clutch is pressed it will flare back up to 3k. this seems to continue for some time before eventually settling, but its only ever after stopping then restarting.
340 never did this, and am wondering if its ecu related? the IAC valve was replaced when i got the car, as this was first thing that appeared to be cause, but is still doing it. any thoughts??
Throttle bodies/flaps sticking?
The only thing would cause the clutch pedal to have an effect on the RPM, is if the throttle cable is being caught by the clutch pedal somewhere in it’s travel. It might be sticking out a bit more than usual where it comes out of the centre divider, if it is being caught anywhere and being put under tension it would explain the high idle you are seeing.
The throttle arm itself is also problematic to return to zero sometimes, but would not be related to the clutch pedal. Check that the arm and pivot housing is tight, 2 star screws holding the assembly, and that you cable goes nowhere near the clutch during any of its movement.
Tone
I’m sure Magnecor are quality leads and I know what you mean about water getting in. I’m just trying to justify staying with the standard ones
Had no problems in 6 years with standard ones, except breaking off part of the end connector that fits on to the top of the spark plug, and even then I think this was done by a ham-fisted service technician.
Throttle bodies/flaps sticking?
Do you have much experiance with “sticky flaps” then Russ??
the IAC valve was replaced when i got the car, as this was first thing that appeared to be cause, but is still doing it. any thoughts??
Happened to me as well and the problem dissappeared when I unlugged the IACV. Ended up removing it, but I’m not happy with the idle without it.
Had a look at some Rover forums and they’ve had the same, it ended up being the wiring to the IACV, some false contact.
Think over the winter I’ll reinstall the IACV. Will have to check the wiring though.
Uldis,
If the TBs are properly balanced and the fuelling is trimmed correctly the engine should idle happily with no issues. The airflow requirement for idle is around 5 KG/min
Dave
I guess the thing I don’t like is that for it to idle at the correct RPM’s when hot, have to set it to idle fairly high when cold and I don’t like that.
At least the IACV took care of the cold-hot differences.
Bought one of those vaccuum idle thingies to balance, so that’s ok.
Steve
It’s largely down to what you are confident with
The standard leads worked fine for me, for 60 odd thousand miles - but I never felt confident in them – and even when the car ran out of petrol I still soaked the old spark plug leads with WD40.
For the �61 Magnecor leads cost, it’s worth it to me just for that confidence I have gained. Neither of us are right and neither of us are wrong - except I’m �61 poorer.
…and they are a nice bue colour rather than black rubber!!
Uldis,
I guess you mean the other way round with the idle speed 
.
There is a knack to getting the idle right at all temperatures, if you use 0 advance at idle that will suppress the speed when hot, some judicious trimming of the coolant corrections for fuel and ignition will also improve the cold idle.
Dave
Throttle bodies/flaps sticking?
Do you have much experiance with “sticky flaps” then Russ??
yeah, they are always stuck shut!
Have you checked all the vacuum hoses Jon.
will take all this advice and see what i can come up with.
cheers all for now
ok, will clarify - is not the clutch. if i leave the car in neutral it makes no difference. what is extremely odd, it is linked to the wheels moving. if the car is still, will settle on 1250 quite rapidly, if the wheels are rolling at all, the revs flare to 2/2500. tested this on a slope so no accelerator involved at all. could this be something to do with a wheel speed sensor??
why would the revs increase simply in response to the car rolling forwards??
the current solution has been to fit an air restrictor to the IVC so that it won’t flare. starts a little harder, but seems to be effective so far. can still tell the car is trying to surge though.
From memory of the K series
When the engine temp are low the ecu puts the idle up when it detects a certain speed … id check the ecu temp sensor