Missfire / hesitation only off boost
Turbo Mini Forums

So last night I finally got the rebuilt engine back in the car. Nothing but the pistons have been changed after melting one, everything else exactly the same.

I guess I was foolish to think I could just plonk the engine back in and everything would work like before.

Engine fired up fine although I did have to tweak the idle screw and idle mixure a touch just to dial it in.

Took it off for a drive down the road and there is was a definate missfire / hesitation, very lumpy indeed but seemed to smooth out once on boost.

Back to the garage and I checked the dashpot oil...empty DOH!, filled it up with Dexron III (opinions?) and took it out again, it did seem better this time but still hesitant, again once on boost it seemed nice and smooth.

http://turbominis.co.uk/forums/index.php?p=vt&tid=170151

Try some 20/50engine oil im having a similar issue where snapping the throttle open gives a masive lean out but its spot on (ish) elseware

Yes i moved to the darkside

Instagram @jdm_brett

Ok, so I swapped out the Dexron for the last of my 20/50 but it turned out the problem was a knackered spark plug!

However, I now have the opposite problem with a very rich flat spot between 1000-2500rpm, afr is reading 10 and the engine struggles a bit, once you get the revs up and some air in its fine.

could the dashpot oil be too thick?

http://turbominis.co.uk/forums/index.php?p=vt&tid=170151

are we talking foot to the floor at 1k sort of acceleration if so yes
is the part throttle lean of connected?
if that is yes too, i would also guess that is contributing to the problem

Yes i moved to the darkside

Instagram @jdm_brett