M52 B28 smoke under load, but good compression? Help Please!

[Macdaddy325]

Been lurking on here for ages but not needed to post until now...

As the title says really got an M52 (Nikasil block) converted E30. It puffs black/grey smoke on full throttle/ high RPM. I know this is pointing towards the Nikasil issues but had a compression test done and 5 cylinders averaged 190 and one 180PSI. It uses some oil but not excessive amounts. Idles fine and pulls really well!

Just wondering if you guys could give me any pointer for what to look at next? any ideas what it could be?

Any help would be appreciated!

Thanks,

Alex

[anderson]

Hi mate, im no expert but doesnt sound like its burning oil then as that would make blue smoke, black smoke i think is unburnt fuel which could explain why it pulls well.
Try unplugging the lambda sensor maybe or look at the fuel pressure.

just a few ideas, i may be wrong on that theory.

[DanThe]

Does it have both lambdas fitted? If the ECU is running the engine in limp mode it will overfuel anyway.

[Macdaddy325]

Both Lambdas are fitted but i will check they are tight and wires etc are ok. I suppose it would be worth have a Diagnostic check done, see what comes up? I also have an M50 intake manifold but a standard TB, would a BBTB help?

Thanks for the help,