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View Full Version : Misfire in high gear 1750/2000rpm...


phoenixcsl
03-06-2014, 06:16 PM
After 4 months of being without Cecil, he finally came home on Saturday...

Had my Schrick Cams fitted and a few other bits done such as a service, and had the front end re-sprayed from stone chips and the wheel arches, looks amazing.

So, when talking to ML they noticed a misfire approx 1750/2000 rpm, on the test drive it was hard to reproduce, so I took the car, said i'll run around in it for a few days and if it comes back will bring it back to get sorted.

Figured out that if the car is at the rev range and say i'm in 6th (normally i'd be in say 3rd so wouldn't notice), and then you go to WOT, there is a noticeable misfire, annoyingly, drop the gears and all is fine, no EML or warning lights, though the misfire is recorded on Cylinder 3 in the fault code.

They have fitted a new coil pack to the car, and new plugs, but neither have cured it, the coil packs are all Bosch ones which I replaced the lot last year, but they fitted a brand new Bosch one in just in-case.

What's the next point of call? Injectors? Do these go on CSL's?

Or Vanos solenoid? Though i'm running a Bessian Systems one which I changed last summer.

Any ideas?

alexk
03-06-2014, 09:02 PM
Headgasket maybe ?

shane@mbtech
03-06-2014, 11:46 PM
comp test, then leakdown test.

Monkey
04-06-2014, 12:25 AM
After 4 months of being without Cecil, he finally came home on Saturday...

Had my Schrick Cams fitted and a few other bits done such as a service, and had the front end re-sprayed from stone chips and the wheel arches, looks amazing.

So, when talking to ML they noticed a misfire approx 1750/2000 rpm, on the test drive it was hard to reproduce, so I took the car, said i'll run around in it for a few days and if it comes back will bring it back to get sorted.

Figured out that if the car is at the rev range and say i'm in 6th (normally i'd be in say 3rd so wouldn't notice), and then you go to WOT, there is a noticeable misfire, annoyingly, drop the gears and all is fine, no EML or warning lights, though the misfire is recorded on Cylinder 3 in the fault code.

They have fitted a new coil pack to the car, and new plugs, but neither have cured it, the coil packs are all Bosch ones which I replaced the lot last year, but they fitted a brand new Bosch one in just in-case.

What's the next point of call? Injectors? Do these go on CSL's?

Or Vanos solenoid? Though i'm running a Bessian Systems one which I changed last summer.

Any ideas?


Hi Toby,

When are you thinking about dropping it back down? Fair to say we were a bit pushed for time Saturday when you collected, I'm sure we'll quickly get to the bottom of it when we see the car again:)

phoenixcsl
04-06-2014, 12:06 PM
Hi Toby,

When are you thinking about dropping it back down? Fair to say we were a bit pushed for time Saturday when you collected, I'm sure we'll quickly get to the bottom of it when we see the car again:)

Hi James,

I'll pop back in Saturday, Stuart has to sort out my old splitters and box up the original cam shafts for me anyway :)

Either or no drama mate :)

phoenixcsl
04-06-2014, 12:07 PM
Headgasket maybe ?

Shouldn't be head gasket Alex, they had the head off to replace the cams so it's brand new.

comp test, then leakdown test.

Good shout Shane, James, another job for you ;)

terraphantm
07-06-2014, 07:36 PM
Injectors are a good place to start.

Did you get a remap after fitting the cams?