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

[Saintsteve]

This mornings cold start.. Same again  

Missfire again detected on cylinder 4.

Must be gummed up valve/injector?.. Not sure what to do next, buy some more Cans of Wynns?  

[rich83]

Don't keep cleaning them. Get it to a specialist.have you tired swapping cylinder 4 plug and coil pack around as a pair?

[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 

Don't keep cleaning them. Get it to a specialist.have you tired swapping cylinder 4 plug and coil pack around as a pair?

 

[rich83]

Sorry. Didn't read thread. 

Could be the injector on its way out. Don't tell me you've swapped that too. 

[Saintsteve]

Sorry. Didn't read thread. 

Could be the injector on its way out. Don't tell me you've swapped that too. 

It must need a decoke..as the Wynns improved the running whilst warm ,but obviously not enough to clean the problem.i only used half a can not the complete can so might not had been enough?

[GTI5]

Sorry. Didn't read thread. 

Could be the injector on its way out. Don't tell me you've swapped that too. 

It must need a decoke..as the Wynns improved the running whilst warm ,but obviously not enough to clean the problem.i only used half a can not the complete can so might not had been enough?

You need a borescope to have a butchers.

[QD MBE]

Give JKM a call.  Perhaps once sorted a catch can would be beneficial? Would help in the long run.  How many miles?  what fuel used?

[Saintsteve]

Give JKM a call.  Perhaps once sorted a catch can would be beneficial? Would help in the long run.  How many miles?  what fuel used?

A catch can has proven useless by other members, so I won't waste my money on fitting one, car has done 67k, and always run on Tesco 99.

Been doing long runs recently and it's still the same. ( up to Solihull etc this past weekend)

Need I think to find someone that will do a compression check, and do a decoke, without going to the expense of a head overhaul.

Car only shows idle speed missfire at idle, no issues up the rev range, and Cold starting if the cars left to idle for 20 seconds , the fault then also appears.The Wynns has made a difference so to me it must be a case of working out best way next without huge expense as its something I could really do without right now.

Need to find someone in Hampshire that offers something like terraclean ?

[Saintsteve]

Walnuts anyone?


http://www.e90post.com/forums/showthread.php?t=682116

[Hedge]

By the time you've tried all sorts of remedies that are ineffectual it would have been cheaper to get the head popped and cleaned.

At least pay someone to take the intake manifold off so you can see if it is the valves that are coked up.

[Saintsteve]

By the time you've tried all sorts of remedies that are ineffectual it would have been cheaper to get the head popped and cleaned.

At least pay someone to take the intake manifold off so you can see if it is the valves that are coked up.

Will do 

[GrayMK5GTI]

Steve I have a can of something in the shed thats designed to clear gunk off valves, i'll let you know what it is. Could always bring to JKM (if your coming?)

Graeme

[gobbleplease]

Hi I'd be interested in the rough price you are getting charged for the cleaning / de-gunk let us know how it pans out

[ROH ECHT]

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.

 

edited:
mass air / .8g/s = whp
mass air / .68g/s = crank hp

Group 002 will. Intake air mass should read a minimum of 0.8(g/s) * WHP  if whp is known (I believe it is 0.68 for bhp). If low or even close to the minimum it needs replacing now or soon.
Another way to quickly check the maf sensor is swap yours using a bud's not having the issue.
Have you replaced the #4 plug yet?
I clean my valves every 10k miles and have had no misfires through 93k miles.
Cleaning the valves my way:

[chungster]

Did u get a look at what the plug was like on 4 compared to the others?

Darker or lighter?

Think it's time the intake manifold came off for injector swap.