190e Cosworth 2.3

[earthvisitor]

Hi.

I've seen a 1986 190e Cosworth for sale which has apparently had a service, new distributor cap and fuel regulator.

Seller says it backfires occasionally and needs a tune.

Can anyone tell me whether anything else more serious than lack of tuning could cause backfiring eg cyl head probs etc.

Are there any problem areas to look for on a 2.3 Cosworth?

Any advice would be gratefully appreciated.

Thanks