S54 miss fire but it was more than that....

[PDJ]

Ok so here is what happened and what I found out along the way

So it started like the traction control cutting in as the road surface was poor, but it was a miss fire it stuttered along a few 100m then cut out and coasted it re started on the key and carried on around 600mm to work

Clocked on returned to the car read the codes

Combustion chamber igniting failure cylinder 5 (or words like that) at this point the engine is off so I thought I would re start the engine to see if any other cyclers where affected but it did not turn a full turn before it stopped dead

It looked like a plug and coil at first

Made a call to Darren Wood (note he is booked up until late May) and one of the staff said I should turn it over by hand it was hard to turn by hand with the plugs in and lumpy so plugs removed and it turns over but spat out a spoon full of fuel from cylinder 5

Called Daren back he suggested am injector stuck open

So timed the call to the RAC for the end of shift

Tried to turn the engine over with the plugs out on the key but only a wiz type sound NO click for the solenoid


This was repeated by the RAC man and as there was not starter motor locally he arranged for a low loader to take me home

One of the operators at work came out to look and we tried to turn the engine over on the key it does not move "See told you" and I turned it over by hand at which point he was covered in half a litre of fuel as it ejected from Cylinder 5

So it becomes clear that the injector was open all the time and filling the cylinder with fuel and the first time I tried to turn it on the key it hydro locked the clear risk here is a bent rod but with very little inertia and the engine not firing up a low risk.

Recovered home

injectors off the car how hard can it be to get some well BMW and Bosch will have so in July if you are lucky and at £325 each so £1950

No one else has any I did try

So contact Simon Thorpe Motors and John at JC Racing both brilliant via text with help so I end up driving 20 miles to a works unit to pick up 6 second hand injector and the man John had recommended said I could have them just have them but I would need to get some new O rings

Back to BMW £140 for 13 O rings or 22 as the ONE from the fuel pipe to fuel rail only come in a bag of 10

All fitted

Tried with the starter motor no go so new starter motor fitted it spins over

Oil changed as fuel will have got into it not worth the risk

Spun over until oil pressure shows on dash gauge ( I fitted one)

Plugs in coils on all back together and it runs

Drove it a short test and it came back sounding like a Millington in a MK2 Escort Power was ok above half revs (I did warm it up properly) but horrible below 2500 and tick over was only just managing to stay running

Now the next bit could be luck but found one thing the pipe between the air box and the bit in the bumper was not lined up so an air leak but before any sensors and I fiddled about with the Vanos connection

Started again and tick over spot on and drove it again and pulls like a train as it did before

So the man who gave me the injectors (very nice man) also knows the S54 engine very well his opinion leave it standard as in the real word it is faster than tuning it for a few BHP at the top end and loosing 3 times lower down, but make sure you have the Vanos serviced as this is what makes it so drivable as I found out when something made mine stop working it was gutless low down almost like a lumpy turbo lag

Hope that makes sense and may help someone there is a bit more detail but that is enough typing and probably enough bad spelling for one night

[beanie]

s**t, I’ll bet your heart was pounding when that fuel came out. The thought of bent rods must have been eye widening!

Not sure I get which pipe from airbox to bumper you mean. If it’s the flexible opening that connects to the airbox and is fixed to the front slam panel/rad support, then it’s before the MAF and can’t really have been affecting anything. At worst a little less air for the airbox but I can’t see it causing big issues.

Either way, seems like you got away with it, and aside from the offensively expensive O-rings, relatively cheaply I the grand scheme of things.

[PDJ]

Not sure I get which pipe from airbox to bumper you mean. If it’s the flexible opening that connects to the airbox and is fixed to the front slam panel/rad support, then it’s before the MAF and can’t really have been affecting anything. At worst a little less air for the airbox but I can’t see it causing big issues.

Yes that one Ito can't see it making any difference but it was one of two thing that I adjusted so it must have been the Vanos connection that was the cause which makes sense as it ran like it was off cam at low revs

[PDJ]

I’ll bet your heart was pounding when that fuel came out. The thought of bent rods must have been eye widening!

Was not happy but it was only cylinder 5 so one rod but still an engine rebuild

It turns out there is a sprag clutch in the starter motor that broke and save everything else

[PDJ]

aside from the offensively expensive O-rings,

the 9 extra ones I have no use for I will be sharing them with Simon, John and Wayne for the help as would save them buying 10

[beanie]

I’ve had to buy 10x of things before from bmw and it’s always when I need just 1 thing. I’ve bought a million clips and bits for my old golf and I don’t think I’ve ever had a minimum order no. for them. Poor show imo.

The sticking injector has been mentioned on the S65 as well, let’s hope it’s not something that becomes more common with age. I wonder if it’s something that could be prevented with injector cleaning?

[PDJ]

The sticking injector has been mentioned on the S65 as well, let’s hope it’s not something that becomes more common with age. I wonder if it’s something that could be prevented with injector cleaning?

From JC Racing when I asked about cleaning and servicing them

We are an asnu dealer

I won’t touch s54 injectors as there usually leak after you clean them

[AndyBeech]

I won’t touch s54 injectors as there usually leak after you clean them

Yup, I had mine cleaned, bad idea. Luckily I managed to buy new ones when they were still available for a decent price

[beanie]

Good to know, thanks guys