General Rough Idle

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General Rough Idle

BenW

Former 999cc CLX Owner
Joined
Mar 13, 2006
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Location
Essex
I've had a rough idle on my panda (999cc CLX) for a few months now, it started about 50 miles after i topped up with tesco premium unleaded and got a bit worse before staying constant. I tried some shell premium unleaded which i know works well but this didnt clean it out.

The engine was stalling when slowing down whilst coming upto roundabouts etc which was hugely frustrating and dangerous so i ended up driving with the choke out to stop it.

The idle speed has been raised since so i can put the choke back in but i want to sort this out (MOT due soon)

Any ideas what it might be? Vacuum advance? HT leads? I've changed the spark plugs, air filter, oil filter, fuel filter and oil with no effect

Thanks
Ben
 
Sounds like a classic case of vacuum diaphragm failure, or if not that it's probably an induction air leak. Check the diaphragm by pulling off the vacuum pipe from the carburettor end then try and blow/ suck through it. If you get resistance then the diaphragm is fine. If no resistance then it has failed and needs to be replaced.

Good luck!
 
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Thanks :) I thought i'd tried that but i was blowing down the tube from the vacuum end, guess that didnt really make sense!

Where would i be checking for an induction air leak? Checking the air box etc?

I cant check the car until im home from uni which is saturday 21st June and the MOT is due Monday 23rd so i want to try and order some bits to fit as soon as i get back

Thanks again
Ben
 
Hmmm, would the carb mix just go wrong like that?

Where would i be looking for an air leak?

Thanks again
Ben
 
I've had a rough idle on my panda (999cc CLX) for a few months now, it started about 50 miles after i topped up with tesco premium unleaded and got a bit worse before staying constant. I tried some shell premium unleaded which i know works well but this didnt clean it out

Tesco poisoned my car(Stilo) last year with their dodgy petrol. Had to have the petrol tank emptied and a new lambda sensor fitted. They did reimburse us though but it made the car chug like a tank and it slowly got worse.
 
It wasnt at the time when the tesco petrol stuff got in the news, this was at the end of march/start of april. A freind had the exact same problems in his fiesta (also carb'd) with premium tesco fuel at the same time, he said injector cleaner made it a bit better although im not sure that would help?
 
Hi, is your car the CLX with fuel injection ? If it is I did have exactly the same problem, I changed everything, and still it ran like a bagofpoo. So I did a 'factory reset' on the ECU, and all was cured ! I spoke to someone who works at a dealers last weekend, who said they were'nt the most reliable of ECU's and do now and again lose memory and cause things like the fuel/air mixture to change etc. If you want to know how to do the reset, PM me.
 
If you disconnect the battery for ten minutes or so doesn't the ECU reset?
(It does in other cars I think) remember to have your radio code handy (if applicable) though.
 
It wasnt at the time when the tesco petrol stuff got in the news, this was at the end of march/start of april. A freind had the exact same problems in his fiesta (also carb'd) with premium tesco fuel at the same time, he said injector cleaner made it a bit better although im not sure that would help?

The dodgy fuel mucked up the Lambda sensors and so only affected ECU controlled cars.

Jon.
 
Had a few PM's about this so I thought Id post it up :

ECU's in panda CLX's are the type that constantly learn, this is because they comensate for engine wear, how theyre driven etc. Occasionally they seem to lose memory, I have to do this quite regularly to mine, but it always seems to cure odd running.

Right, the instructions can be found in a late model haynes manual, but; off the top of my head:

Loosen the bolt that holds the earth lead to the battery, and leave the bonnet open.

Start the engine, keep it running untill the fan cuts in.

Let the fan go off.

Let the fan come back on again, then quickly turn off the ignition, and dissconnect the earth lead on the battery.

Leave off for approx. 45 seconds!

Re attatch the earth lead, and start the engine let it run for atleast two minutes.

In the manual it says the car may run oddly for a few miles untill it re-learns the optimum settings

Hope this is of some use........................................
 
ECU's in panda CLX's are the type that constantly learn, this is because they comensate for engine wear, how theyre driven etc.

This is where I'm probably going wrong then, lol. One day I can be driving like a mad man, and the next, like and old man trying to get the best MPG out of his car.

Any way, thanks for the PM.(y)
 
Replaced the vacuum advance yesterday and all working properly again :)

Thanks :D
 
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