Having run ok for 10 months since purchase including track days the car has started misfiring today when HITD {her inside the doors}took it out.Usual mods have been undertaken,ie apexi filter,3" decat stainless steel exhaust,rolling road tune at SAS aldershot gave 297.5 @7200rpm.Always use Shell super unleaded and Repsol 102 octane for trackdays .Tried pulling HT leads off coil pack to see if i had duff spark plug but not really conclusive other than spark off top right lead{3or 4?] seems very weak.The coil pack is type Diamond F-569 are these known to fail around 3 yrs old?

 

Try draining out the AVGAS

Misfires are not good for turbos btw!

 

Hows your engine?

 

Bigger,better,stronger....but still in bits

 

All electrics register ok on select monitor check,think timing belt has jumped a couple of teeth!told it has been known for hydraulic tensioner to give trouble,cambelt changed 3 months ago using Dayco belt from GGR.Start stripdown on monday.

 

Sorted,cambelt had indeed jumped 4or5 teeth,but jumped the wrong way?This could have been due to the engine "kicking back" like a big 4stoke single bike engine.Anyways new genuine belt fitted and goes as good as gold.

 

Was the tensioner OK?

 

Pete,i am told the tensioner was ok,which i assume was the distance of the protusion of centre rod from body ie 15.4-16.4mm maximum as per info from Autodata manual.Have you changed any tensioners on 3 to 4 year old sti versions?Note i allways change oil {mobil motorsport 1 15/50} and filter at 5000 miles bearing in mind tensioner is hydraulic/mechanical spring.

 

If the tensioner was OK, there is no way the belt could have jumped.

The tensioner is a hydraulically damped spring unit. It is independant and not fed by engine oil or pressure.

We have never had to change a tensioner.

 

Ah!

 

Best i buy a new tensioner then to fit before Goodwood this sat the 11th on the D.K Paul test day.