gra2730

iTrader: (1)

Hello.

As title, what readings should I see for lambda, maf, knock, boost etc etc on the printout so I know whats right & whats not, just want to understand more of whats going on with my engine & £45 for a diagnostic it would be good to know before I see it.

I look forward to hearing all your expert advice!!!

Cheers

cjs5ub

mmm...lamda 1 you should see as this is perfect air to fuel ratio ..boost you can only read while driving about 1 bar max as standard ...knock sensor will never affect your car running or performance its there to detect noise in the combustion chamber and thats it i.e knock sensor ..hope this helped you. chris

saiklon

Lambda (AFR) should be about 14.7 on cruise and start dropping as you get onto boost. It should be at most 12.5 at about 0.5bar and go richer from there. At full boost, it should be at most 11.8. Anything leaner and you need to remap ECU/replace fuel pump.

MAF should not get much above 4.7V, since that is about the top range of the MAF scale.

Knock: You should not have consistent knock on every run, otherwise you need a remap.

Boost should be about 0.9bar to 1.2bar max for a stock car I think.

Note: The above figures are based on what I think are the parameters of a safe tune. Other people might choose to be more aggressive or more conservative.

gra2730

iTrader: (1)

Thanks that is really good info, what should the lamda read at idle out of interest, I am running a standard map and car so would expect to see it all within the normal figures, just trying to pinpoint sone hesitation.

gra2730

iTrader: (1)

Chris what is the perfect air/fuel ratio from tickover to wot, any ideas?