back firing?

[bmwbreaker]

Hey Folks

Right the story goes like this....

I have a carb'd m10 engine in my 316 E30. Someone previously had fitted 45's to it and removed them before I brought the car.

So i got hold of a weber carb and fitted that along with a new fuel pump and now it tries to start and back fires on an odd occassion!!!

Never had this before and was wondering what people would diagnose it as being??? I did have it started once and it was running ok but at certain points in the rev range would get very tapperty and then suddunly stop and then get tapperty then stop (all dependent on where I was in the rev range???)

Strange I know but hopefully someone knows whats going on

Phil

[TVRTASMIN]

Could the rattling or tapping noise be a lean mixture because the float bowls are emptying or the timings out.
Webers don't need much fuel pressure but if the flow is not there they could be getting starved.

[bmwbreaker]

Could the rattling or tapping noise be a lean mixture because the float bowls are emptying or the timings out.
Webers don't need much fuel pressure but if the flow is not there they could be getting starved.

The whaa? lol you've totally lost me with the float bowls? I fitted an entirely new fuel pump so I would have thought it would have been ok?

Out of interest upon fitting the pump there was just a rod coming out of the head. I simply pushed the spring from the pump down onto this rod and bolted it tight? would this be correct?

[julianm40]

Hi mate, i used to have a 316 carb, it backfired like hell and spat flames!! It was on a standard carb with an el cheapo stainless rear box. I think its just the nature of the engine.

Julian