Idle speed and coldstart issues on Edition 30..Terraclean to resolve..

[Saintsteve]

Sorry if I've asked in the wrong place, but does anyone know what readings on VCDS to show my MAF is working correctly ?

Trying to cure a cold start Miss-fire, that disappears after 1 minute of idling, but don't wanna splash out over £100 to get a new one if my diagnosis is wrong.

 

[bacillus]

Can't help but tried cleaning it?
http://www.ebay.co.uk/itm/CRC-Air-Sensor-Clean-Mass-Air-Flow-Meter-Cleaner-MAF-200ml-/271154164864?pt=UK_Car_Accessories_Car_Care_Cleaning&hash=item3f220c3480

[Saintsteve]

Can't help but tried cleaning it?
http://www.ebay.co.uk/itm/CRC-Air-Sensor-Clean-Mass-Air-Flow-Meter-Cleaner-MAF-200ml-/271154164864?pt=UK_Car_Accessories_Car_Care_Cleaning&hash=item3f220c3480

I have bought some of this today to flush it out with..


image by Saint steve, on Flickr



Trouble is , it missfire's like a bitch from cold, as soon as the revs drop from 1200 to 750 on warm up, approx 1 minute after cold start, the engine stops misfiring . No errors show in VCDS neither, my recent Emmisions tests have been poop recently and so has my MPG, so I'm wondering if this is the cause. Since having the Twintake installed, its been a problem. Might be coincidentle?

Any ideas?

[Hedge]

Do it with the MAF disconnected.

[Saintsteve]

I removed it 1st thing this morning, seem to clear, but didn't occur to me till late. Might of been where car had warmed after 1 minute, before I thought to do it. Gonna try in the morning and see if its cleared.

Just wanna be 110% sure before paying out. But with high emissions readings and higher then usual fuel consumption, might just bite the bullet.

Car is fine over wise .

[chungster]

oh dear not you as well having a cold start mis-fire. seems to be a lot of mis-fire issues of late.

have you confirmed it's a proper mis-fire though? blocks 15 and 16 will tell you if it's happening on all cylinders or just individual ones. then you can start narrowing down things and finding the problem

[Saintsteve]

oh dear not you as well having a cold start mis-fire. seems to be a lot of mis-fire issues of late.

have you confirmed it's a proper mis-fire though? blocks 15 and 16 will tell you if it's happening on all cylinders or just individual ones. then you can start narrowing down things and finding the problem

I will take a look, but as I said, its not showing in a full scan of errors ?

[Hedge]

An autoscan wont generally show up misfires.

[Saintsteve]

An autoscan wont generally show up misfires.

Ok.. To update, I logged 15-16 and indeed, shows I had a bad idle missfire on cylinder 4. Logging over 40 missfire's on each cycle of scan..

1st thing I then did was swop coil packs, then spark plugs from cylinder 1 to 4 to see if fault would hopefully move.But alas it didn't  

So consulted the knowledge of a forum legend ( hurdy) and after disconnecting the MAF, the rate in which the missfire's were happening was less.
So it pointed to Dirty Gummed up exhaust and inlet valves.So use the Can of Wynns via the MAF port , whilst holding revs at 2000 rpm, and spray contents in , in stages .The results were conclusive, the rate of missfire's got even further less down to under 20 per cycle. After putting engine back together , road test and a 2 mile quick sprint, missfire's are now at Zero and interestingly, my idle speed has increased to 780-800 and not hint of judder on engine note and also a very smooth idle.

So the moral of the story is, that I'm gonna go buy another can tomorrow  

£9.99 at Halfords


image by Saint steve, on Flickr


Thankyou Ian and lee for the heads up about live missfire logging  

[GrayMK5GTI]

I bought a similar product but never tried it.

Glad that solved your problems Steve 

[Hurdy]

Glad it was that, I was mulling over all sorts of scenarios!

 

[GTI5]

An autoscan wont generally show up misfires.

Ok.. To update, I logged 15-16 and indeed, shows I had a bad idle missfire on cylinder 4. Logging over 40 missfire's on each cycle of scan..

1st thing I then did was swop coil packs, then spark plugs from cylinder 1 to 4 to see if fault would hopefully move.But alas it didn't  

So consulted the knowledge of a forum legend ( hurdy) and after disconnecting the MAF, the rate in which the missfire's were happening was less.
So it pointed to Dirty Gummed up exhaust and inlet valves.So use the Can of Wynns via the MAF port , whilst holding revs at 2000 rpm, and spray contents in , in stages .The results were conclusive, the rate of missfire's got even further less down to under 20 per cycle. After putting engine back together , road test and a 2 mile quick sprint, missfire's are now at Zero and interestingly, my idle speed has increased to 780-800 and not hint of judder on engine note and also a very smooth idle.

So the moral of the story is, that I'm gonna go buy another can tomorrow  

£9.99 at Halfords


image by Saint steve, on Flickr


Thankyou Ian and lee for the heads up about live missfire logging  

Good to hear you've made some progress. Did you inject the fluid by removing the IAT sensor?

I still don't think this stuff can shift much off the coked up valves but it might have dislodged some lumps hanging on?

[scopes]

Glad you got it sorted Steve    How do you log 15-16 ? If you dont mind me asking, I seem to be getting more of a splutter in the morning, 2 mins down the road when i have to add abit more pedal for a busier road, it only seems to have come on more recently...

I am wondering is it something the same, i stuck a new maf in tonite so, i will tell if it has helped in morning, as it only happens when cold an left overnight...

I am not one for having to be hard as the car has not fully warmed up yet, but at times i have no choice but speed up abit,, just for a short distance and not for too long.. It does thow up some what looks like exhaust fumes or steam, which cover the back window...

again no faults coming up on vcds... it has me baffled.

the only thing that has changed is a new clutch fitted, now with over 1000 miles on it, so should be worn in abit ...
and an oil change at the same time...

Don't mean to highjack your thread, just incase its along the same line mate 

thanks 

Neil

[bacillus]

  How do you log 15-16 ?

Open vcds>select>engine>measuring blocks>enter 015 in the first box>go. Do the same in the next box for 016.
Click log>do a run or just look at the numbers by pressing start. Click stop when finished.   

[Saintsteve]

An autoscan wont generally show up misfires.

Ok.. To update, I logged 15-16 and indeed, shows I had a bad idle missfire on cylinder 4. Logging over 40 missfire's on each cycle of scan..

1st thing I then did was swop coil packs, then spark plugs from cylinder 1 to 4 to see if fault would hopefully move.But alas it didn't  

So consulted the knowledge of a forum legend ( hurdy) and after disconnecting the MAF, the rate in which the missfire's were happening was less.
So it pointed to Dirty Gummed up exhaust and inlet valves.So use the Can of Wynns via the MAF port , whilst holding revs at 2000 rpm, and spray contents in , in stages .The results were conclusive, the rate of missfire's got even further less down to under 20 per cycle. After putting engine back together , road test and a 2 mile quick sprint, missfire's are now at Zero and interestingly, my idle speed has increased to 780-800 and not hint of judder on engine note and also a very smooth idle.

So the moral of the story is, that I'm gonna go buy another can tomorrow  

£9.99 at Halfords


image by Saint steve, on Flickr


Thankyou Ian and lee for the heads up about live missfire logging  

Good to hear you've made some progress. Did you inject the fluid by removing the IAT sensor?

I still don't think this stuff can shift much off the coked up valves but it might have dislodged some lumps hanging on?

Yes, , just start her up, someone on the loud pedal at 2000rpm and squirt every 15-20 secs depending on revs.
Been out in it tonight, certainly a lot happier on idle speed, but truth be told what she'll do in the morning is what it's all about.
Update to follow in the morning.