AG2728

I can't get the link to work :(

One place for me please Paul.

Andy

Thanks again Dave 

Mine is a Duratec but I had exactly the same symptoms you describe - a misfire high up the rev range.

I changed all the usual suspects, plugs, coil packs etc but still the same.

My dealer couldn't diagnose it and said it was likely to be the imobiliser which they then modified.

Still no joy. Took it to Northampton Motorsport who put tested it on the dyno and it proved to be a failing throttle position sensor.

Andy

The earplug thing had always baffled me because I have a 420R and have never considered it to be particularly excessively loud on the move (in terms of sportsbike kind of loud). It has been the only 7 I have driven so have never had anything to compare it to.

My car however has the rear exit exhaust and this week, for the first time, I had the opportunity to drive someone else's Duratec engined car (360R). This had the standard side exit exhaust and I can now understand the earplug thing. From the cockpit, the difference in volume is huge.

Andy

Thanks for having a look at it. Graham, Alan, Paul.

I think I was the only one present at 3 Sisters whose novice score was shown as being based on a percentage of fastest class time of the day. I can see that this was obviously because there were no class 4 entrants in 2017. Even if I had been scored against class 6 times from 2017, I reckon I would have been 15-20% better off.

What I had considered to a particularly unsuccessful day for me at 3 Sisters became even more unsuccessfuller once I saw the results sheets......... and wept. 

Andy

I swapped mine for a set of 6 point Schroth. Not the cheapest but they seem to fit the Tillets better and have pull up rather than pull down strap adjusters so it is so easy and quick to get them on compared to the OE items.. Would highly recommend.

Andy

#2 Firstly try going up one hole at a time to ascertain how the car feels on the road .

I would wholeheartedly agree with Geoff.

I use my car (420R) for sprinting and it is purely for track use. I'm running the rear on one hole from full soft at the moment and would actually prefer to use the end (full soft) hole in the ARB blade Unfortunately this is not possible as the drop link and ARB blade then fouls the CV joint under compression.

Obviously just my opinion but I wouldn't even consider going any stiffer on my own car and am even seriously thinking about ditching the rear ARB altogether.

Andy

Thanks again for the pics Dave 

Excellent. Thank you.

Andy

Anybody know if there be access for camping on the Friday night?

Andy

From the 2021 blue book

11.4.2. Competition numbers must be covered at all times when driving on the public highway.

1.5. It is recommended that Safety Cars have the decals removed or covered when on the public highway, and are driven in such a manner as not to bring the sport into disrepute.

2.6. It is recommended that Lead Cars have the decals removed when on the public highway and are driven in such a manner as not to bring the sport into disrepute.

3.4. It is recommended that Parade Cars have the decals removed or covered when on the public highway and are driven in such a manner as not to bring the sport into disrepute.

It's a Motorsport UK thing rather than a legal thing.

Excellent!!!! Thanks Alan.

Was there anyone out there taking photos?

Andy

In the email I got, the COVID declaration is in a hyperlink under the drivers' briefing section.

I had a similar problem with my 420. It would run fine until after about 15 minutes track time and then I would get a misfire. Let it cool down and it would be fine until really hot again. It never happened on the road so it seemed to be temperature related.

I fitted a new set of coil packs and next track day, the misfire occurred again. I took it to Northampton Motorsport who managed to replicate the issue on their rollers and it turned out to be a faulty throttle position sensor.

Have you always used the same filters and for that mater the same oil...?

Yes. Always the same.

Do you think the filter is the source?

It's very much a possibility. I have replaced it with a Mann filter though today. After 3 flushes with no signs of any debris whatsoever, I am now inclined to think it was an event, as opposed to an ongoing issue.

So for now I intend to try to pretend it never happened and will drop the oil again, following a day at Oulton next Wednesday.

Andy

What do your learned colleagues think of it? Do you have access to oil testing?

Learned colleagues as stumped as I am.

Yes have access to oil testing but the tests are generally to tell us which kind of metal is present, in what quantities and therefore which components are failing.

In this case, I don't have metallic debris. I usually find where no metal is present that the report would just probably tell me of carbon content and that there is excessive fuel present in the engine oil. I have stacks of reports like this.

No additives at all.

Not tried reheating but good idea. Original Caterham branded filter. 

The debris seemed to be free flowing until it cooled. The colder it got, the more coagulated it became. It was all the same stuff. 

No. It's the tall Raceline fabricated tank sat ahead of the engine. 
I have done 2 complete flushes with some random Shell Helix from the local petrol station tonight and left to drain. Not a sign of any debris at all.

Will fill it with he proper stuff tomorrow and see how we go (Unless it's the proper stuff that my engine doesn't like). I still have no idea what it was all about. 

Casting sand from the bell tank??

The debris was not present on the 2 previous oil changes, using the same oil. Millers CFS 10w50 NT+.

I don't think its rubber. I can crush it to dust in my fingers. The strainer was actually very clean as this stuff would just flow through it under pressure and then just congeals when left. The only place it seems to have been captured (marginally) is in the paper filter element. The filter looks intact.