DEC14N

Ok im not technically minded at all so sorry if i appear silly for asking!
I have a my96 turbo wagon thats done 108k, recently noticed on two occasions several weeks appart that when I put my foot down say to overtake something the car leaves a puff of dark smoke behind her.
doesnt do it when you start her in the morning, runs the same as always, no strange noises, only thing is i have started using tesco 99 ron fuel in the last month, not on every fill up but dont use optimax as much now.
Her fuel consumption seems to be a little higher than usual but that may be me being paranoid!
Any ideas?? I get the strange feeling it may be very expensive!

dr_jones

iTrader: (1)

Overfuelling can often be the cause of black smoke.

Can't see that a change of fuel would be in any way responsible for this and as lambda sensor is not used at WOT as in an overtake situation the more likely culprits I guess could be MAF reading abnormally high / some ECU issue.

DEC14N

Thanks dr jones, the car has had maf related issues before but never did them long enough to warrant changing it but may be worth a go now.