Getting engine knock at high revs when accelerating hard, only thing that has been changed is the plugs which are now 7b instead of the 6b that the car was mapped on. Think they were set to 0.65, could this be causing the knock? The old plugs were causing the car to misfire as they were knackered, last resort will be to get some new 6b plugs. Other option is the car has Apexi Power FC ECU, is there any settings that i should adjust? Not able to get the map checked/tweaked at the moment.

Any advise apreciated.

 

Are you currently using a lower octane fuel to what the car was originally mapped to use?.

 

Using V Power, was mapped a couple of years ago before Shell changed their fuel to Vpower, think it used to be 98Ron. Car is MY00 UK turbo with TD05, decat, FMIC, Walbro 255. Never had any trouble last year, car was left unused for a couple of months, when i came to use it the car would judder and misfire on boost which i found to be well knackered spark plugs, car had run fine before being left for the couple of months so found that a bit strange.

 

Could be just a dodgy batch of fuel, have seen this happen before, run the tank almost dry then refill up using a different fuel station just too see

 

^^^
could be, try adding some octane booster (NF of millers) if you have some, see it that helps..?

The mapping for optimax shouldn't make any difference as v-power is better.

Fuel pump isn't getting tired is it..?

 

Are you able to measure the knock count or is it audible?

JohnD

 

could be fuel pump or plugs?

 

Believe it or not, I got more activity on the knocklink when my local garage switched from Optimax to Vpower. I took the car to Bob to check the map and, If I recall, he said that the car needed a bit more fuel added to the map. It may have been that the car was making slightly more boost on the higher octane petrol....I don't remember.

It's good advice to add a splash of octane booster to the mix though, if the knock dissappears, chances are it was just a dodgy batch of fuel. Running cooler plugs should make knock less, not more, likely if I understand it correctly.

Ns04

 

Tried a couple tanks of fuel and still the same.

Kncock varies from 24-36 on the Apexi Power FC commander and have knockling fitted which flashes up.

Fuel pump is only a couple of years old and only done a few thousand miles, does whine a bit tho.

Did not want to reisk putting octane booster in as Vpower has slightly higher octane than the optimax it was mapped on.

I can adjust some of the setting useing the Apexi Power FC commander.

Spark plugs have only just been changed so could be due to changing them from 6B to 7B or maybe the gap is wrong. Not got round to checking the gaps yet.

Cheers for the responses.

 

hope you work it out

 

maf sensor?

 

Not knowing too much about the Apexi Power FC, what is considered too high a knock reading? Is it the big red that flashes on the Knocklink or both orange?
Plug gap should not be an issue as det. would only be spark initiated if the ignition was too far advanced, and thats not the fault of the plug.

JohnD

 

Checked the air flow Maf sensor reading when it started and it looked ok on Apexi hand comander.

Have seen the first 3/4 leds on knockling sensor light up, not the Large clear led. Only used to get the first 2 to light up and max reading on the Apexi was upto around 20.