BrianMoore!Please help!Sorted

[eko]

Can you offer any advice on this problem-

318is belonging to Benjy.
Fitted new clutch with no problems.

Did a few other bits ie
replace coolant/bleed system
cleaned out throttle body with carb cleaner
took out spark plugs(only 2 months old)and cleaned.
Taped up the cracked AFM/TB pipe

Problem is this-

Runs perfect untill the engine is warm(temp gauge at quarter)
then it has a misfire at low revs,as soon as it gets to about 2K rpm it clears and flies.
The temp gauge sits at half when its warmed right up!

Took it to Westerley BMW today and they put it on a code reader!
The result saying that the main culprit seemed to be the AFM/TB pipe
and suspect AFM fault?

Brought the car to my house and put the AFM and pipe from my 318is on it and tryed it,soon as it warmed up problem was still their

Disconnected battery and let the ECU discharge then after a while reconnected and took it for a good blast up the duelly,problem still there!

Have you any ideas please?

Possible Blue sensor problem?

[Brianmoooore]

Sounds like a weak mixture missfire at low revs. It's OK with a cold engine, because it is overfuelled during warm up, and the mixture is sufficiently rich not to missfire.
Commonest cause of missfire at low revs is air leaks engine side of throttle plate.

[eko]

Brian thanks for the reply!

Where do you suggest i try?
Engine-Manifold
Manifold-TB
Checked and secured all the breathers already
Cant physically hear any leaks(i have tried)

Throttle body has been off yesterday to be cleaned out,and wait for it-i didnt fit it with a new gasket.
I did inspect it though and no visible breaks and i used Hylomar on refitting-is this a no-no/suspect?

[Brianmoooore]

As I posted yesterday, in another thread, I don't think I have ever used a new TB gasket!
Last year I had a low rev missfire on a M20. Even when I had proven that No 1 mnifold gasket had failed, I still couldn't hear any thing.
The way I check for inlet air leaks is to take a plumber's type blowlamp, with a seperate gas bottle, remove the jet from the torch, turn the gas on and then wave the torch around near the gaskets.
You will hear the engine respond instantly if gas is drawn in through a leak.

[eko]

Ill have another good check around,maybe even remove the whole manifold and replace gasket(i have one of these waiting to go on mine)and have a closer look!

Thanks for the advice Brian!!

[E30Mark]

Try changing the blue temp sender! had the same problem in mine 6 months back, intermittently the car would miss-fire, then slowly the miss-fire got worse and effected a wider speed range. Changed the sender (Easy access on the M42 engine) and now all OK.

[eko]

Thanks for your advice on this fellas,problem is now sorted!
Benjy is a happy man again

Turned out to be the breather pipe that runs from the back of the engine and goes under the inlet manifold and joins up with the others.
The end had a split in it and it wasnt staying on,temporary repair done using cable ties and plastic tubing(Blue Peter style)untill he orders a complete set of new breathers.
Was a pig to do but has made all the difference!

While we were at it we also removed the water plate thingy that si9ts between the TB and manifold.
Seems to have made the car run noticably smoother and seems a little bit more responsive.

Oh yes,also changed the Blue sensor and this made no difference!

Anyway,thanks Brian seems you were right AGAIN
Legend!