high revs / lumpy when cold
Discussion
posted on this before but still struggling... Start the car no problem, always fires but revs high - about 2500 rpm. If i leave the car it will slowly drop to about 1000rpm but if i drive off it will be reving high again the next time i come to a stop and dip the clutch. the same will happen again, if i stand still long enough, the revs will eventually drop. This situation gets better but never goes away when the engine is hot. This is really getting on my nerves now and is spoiling my fun!
Car has been to the dealer (HHC)and was showing no fault codes...? Thought it might be the road speed sensor but was told this operates the speedometer as well and this is working fine.
Am now thinking it may be the hot wire/air flow meter?
But why would this only happen when on the move...?
forgot to add, when the car is first started and i press the acelerator, the engine almost stops and is hard to rev and generally lumpy until it warms up a bit - not a big problem but thought it might be a clue to the above
Any ideas...thanks in advance for replies
Car has been to the dealer (HHC)and was showing no fault codes...? Thought it might be the road speed sensor but was told this operates the speedometer as well and this is working fine.
Am now thinking it may be the hot wire/air flow meter?
But why would this only happen when on the move...?
forgot to add, when the car is first started and i press the acelerator, the engine almost stops and is hard to rev and generally lumpy until it warms up a bit - not a big problem but thought it might be a clue to the above
Any ideas...thanks in advance for replies
Edited by petea on Sunday 4th February 14:18
petea said:
posted on this before but still struggling... Start the car no problem, always fires but revs high - about 2500 rpm. If i leave the car it will slowly drop to about 1000rpm but if i drive off it will be reving high again the next time i come to a stop and dip the clutch. the same will happen again, if i stand still long enough, the revs will eventually drop. This situation gets better but never goes away when the engine is hot. This is really getting on my nerves now and is spoiling my fun!
Car has been to the dealer (HHC)and was showing no fault codes...? Thought it might be the road speed sensor but was told this operates the speedometer as well and this is working fine.
Am now thinking it may be the hot wire/air flow meter?
But why would this only happen when on the move...?
forgot to add, when the car is first started and i press the acelerator, the engine almost stops and is hard to rev and generally lumpy until it warms up a bit - not a big problem but thought it might be a clue to the above
Any ideas...thanks in advance for replies
Car has been to the dealer (HHC)and was showing no fault codes...? Thought it might be the road speed sensor but was told this operates the speedometer as well and this is working fine.
Am now thinking it may be the hot wire/air flow meter?
But why would this only happen when on the move...?
forgot to add, when the car is first started and i press the acelerator, the engine almost stops and is hard to rev and generally lumpy until it warms up a bit - not a big problem but thought it might be a clue to the above
Any ideas...thanks in advance for replies
Edited by petea on Sunday 4th February 14:18
if it's any help, mine used to do the very same thing. garage (TMS Melton) couldn't find anything wrong with it. lots of beard strokin' and chin scratchin then followed.
it eventually went away after i rolled my sleeves up, got under the bonnet and just cleaned everything - stepper motor, plugs, dizzy the job lot. it still did it for a bit but nowhere near as bead as before, settling into a nice idle after about a minute.
it must be the car preparing itself properly for the road, what with green ones being as fast as they are an all that. nice motor btw
Hi petea,
My guess is that you may have two separate problems here.
The lumpy cold starting seems not be be uncommon - mine also suffers from it (I have been told that changing the coolant temp sensor may help, but I haven't tried this.). This (for me at least) is not a problem as such, more of a characteristic. I just leave mine to warm up for a minute or so before driving off, otherwise I need to use lots of revs whilst slipping the clutch which is no good.
as for your fast idle - the stepper motor might be the first port of call, but equally could be something else.
Good luck,
Pete.
My guess is that you may have two separate problems here.
The lumpy cold starting seems not be be uncommon - mine also suffers from it (I have been told that changing the coolant temp sensor may help, but I haven't tried this.). This (for me at least) is not a problem as such, more of a characteristic. I just leave mine to warm up for a minute or so before driving off, otherwise I need to use lots of revs whilst slipping the clutch which is no good.
as for your fast idle - the stepper motor might be the first port of call, but equally could be something else.
Good luck,
Pete.
Come across this before but not on my Chim. Could be a temp sender telling the ECU that the car is cool and therefore needs to run on choke. This actually happened on a 1ltr polo. Fault finder will not show anything as there isnt an aparent fault - sender is telling the ECU the right info apart from it being out by 40 degrees.
right...here goes!
rotor arm and cap replaced last year at service - less than 3000 mile ago - lucas - timing checked at dealer - spot on
erplaced the advance retard machanism - seems to be working, especailly when hot and the car is stationary
temperature sender replaced about 1000 miles ago - had no effect
ECU is standard as far as i know
Getting a bit sick now - Started to identify what the car (ECU) could adjust that would affect the revs - basically air/or fuel yeh...?
So its either a faulty input that the ECU is trying to counteract and/or a faulty output that is counteracting something that is not actually happening - if that makes sense?
In this months sprint there is an article on swapping over some relays - going to try that as, as the article pints out, it is free - unless i have read it wrong it doesnt seem to tell you what the relays actually do...? anyone...?
Thanks wizzpig - yours looks fit as well!
Thanks again for any help
rotor arm and cap replaced last year at service - less than 3000 mile ago - lucas - timing checked at dealer - spot on
erplaced the advance retard machanism - seems to be working, especailly when hot and the car is stationary
temperature sender replaced about 1000 miles ago - had no effect
ECU is standard as far as i know
Getting a bit sick now - Started to identify what the car (ECU) could adjust that would affect the revs - basically air/or fuel yeh...?
So its either a faulty input that the ECU is trying to counteract and/or a faulty output that is counteracting something that is not actually happening - if that makes sense?
In this months sprint there is an article on swapping over some relays - going to try that as, as the article pints out, it is free - unless i have read it wrong it doesnt seem to tell you what the relays actually do...? anyone...?
Thanks wizzpig - yours looks fit as well!
Thanks again for any help
Petea,
The 2 relays they are talking about in sprint are the two loose ones on the loom in the fuse
box area.
One supplies the fuel pump the other is the ECU relay.
To be honest though if changing round the two relays cured his odd running, the chances are one or both the relays should be replaced and the connector cleaned up as they must be pooped.
Also he may have had a bad connection which was cured by unplugging and swapping over the 2 relays.
Either way worth replacing for the cost of 20 quid and a few seconds with a wire brush.
Cheers
Paul
The 2 relays they are talking about in sprint are the two loose ones on the loom in the fuse
box area.
One supplies the fuel pump the other is the ECU relay.
To be honest though if changing round the two relays cured his odd running, the chances are one or both the relays should be replaced and the connector cleaned up as they must be pooped.
Also he may have had a bad connection which was cured by unplugging and swapping over the 2 relays.
Either way worth replacing for the cost of 20 quid and a few seconds with a wire brush.
Cheers
Paul
Hi,
Start with the stepper motor, as this could be leaking air into the combustion system, It should have a card washer on the inside recessed edge. Always pays to clean this on a regular basis, and also clean the apeture that it fits into!
Have you checked that the throttle cable is the correct lenght?
I had one that showed no error codes, but would not run right, idel all over the shop and backfires, turned out the owner had tryed to adjust the peddle box and upset the throttle cable length!
Hope this helps.
Start with the stepper motor, as this could be leaking air into the combustion system, It should have a card washer on the inside recessed edge. Always pays to clean this on a regular basis, and also clean the apeture that it fits into!
Have you checked that the throttle cable is the correct lenght?
I had one that showed no error codes, but would not run right, idel all over the shop and backfires, turned out the owner had tryed to adjust the peddle box and upset the throttle cable length!
Hope this helps.
Hi,
Mine was doing just what you have described. Now fixed with a very simple cure.
Wife got me a K&N from Act for the 14th Feb, better than roses, and the Chimaera is back to normal with perfect RPM at all the times.
Get your Air Filter cleaned or replaced. If that does not cure it, at least its one the cheapest options.
Colin L
Only problem, what do I buy the wife now???????
Mine was doing just what you have described. Now fixed with a very simple cure.
Wife got me a K&N from Act for the 14th Feb, better than roses, and the Chimaera is back to normal with perfect RPM at all the times.
Get your Air Filter cleaned or replaced. If that does not cure it, at least its one the cheapest options.
Colin L
Only problem, what do I buy the wife now???????
Has anyone messed around with the base idle setting? On top of the plenum near the throttle linkage is a vertical screw. It is normally blanked off with a plastic cap but this will have been removed. Screw the screw down until it stops then back it off 2 1/2 turns. Start the car if the idle is still wrong squash the air bypass hose flat to stop any air passing. this will cut out the effect of the stepper motor. set the idle by adjusting the screw to give about 500 rpm tickover. Release the hose and the revs should rise to around 900rpm. If the problem is still there pinch off the hose & adjust the tickover to 800-900 rpm. see if the problem has gone away. If it has its the stepper motor, if not its something else.
Mine also has the high tick over when cold but not quite as high as your saying, about 1500-1800. I also get a loud hissing noise from around the inlet whenit is cold so im quessing its an air leak causing it but not got round to looking with the weather being so cold :-). maybe this could be somthing to look into.
Thanks for all the replies!
Car already has a K&N filter and assume the ECU is OK as it has been into the dealers and showed no faults. Dealer also checked all the settings - base idle, throttle potentiometer, etc.
As you can tell, this is giving me a few headaches!
You have given me a few ideas to try though...thanks again.
Car already has a K&N filter and assume the ECU is OK as it has been into the dealers and showed no faults. Dealer also checked all the settings - base idle, throttle potentiometer, etc.
As you can tell, this is giving me a few headaches!
You have given me a few ideas to try though...thanks again.
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