strange problem.
Turbo Mini Forums

When cranking the car over with the intercooler off, I get a slight popping/backfiring through the carb around every half a second and puffs of smoke/vapour coming out the plenum, yesterday I tried it with it on, I could hear the popping/backfiring and can see this smoke/vapour rising from around the carb area, took my plunger out from my dashpot and all the smoke/vapour came out

Any ideas? Only thing I can think of is I took the carb off from the inlet and never changed the gasket for reasons I cannot remember, I can squeeze in a couple of hours later afterwork ill whip the carb off and change all the gaskets from inlet/carb/plenum see if this makes a difference, anybody got any other suggestions I could try?

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

Ignition too advanced?

If something is worth doing, it's worth doing half of.

Not sure not set timing yet but I did had a little play with the dizzy but ran out of time, ill have a proper go later on.

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

have you got the leads on correctley ?
and your dizzy set right in relation to the the cam and dizzy rotor etc.... i presume you are running a dizzy benny?

Yep all leads are right, yeah I'm running a dizzy, I'm going to double check everything today and ill report back.

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

I tried retarding the timing until it wouldn't turn over made no difference still does it, its more of a sharp hiss than a pop or backfire? I tried to get a video but the camera can't quite capture the sound.

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

have you got the dizzy spindle set right in relation to the dizzy 1342 firing order ? and you havent got it 180 degrees out ?
CHECK!! ............ if you are sure! time the engine in to 6deg BTDC vac pipe disconnected for this puprose. and report back ben

steve it was at about 2 o clock when i put it in, the timing is not 180 out and the firing order is connrect, i went through all that when it would not turn over properly, just needed the ignition advancing, when i did so it started doing this, there is no inbetween it either pops thorug hthe carb or doesnt turn over.

i have not done the timing i was waiting unti it is running, i have my vac. pipe disconnected and blockedo ff at the carb, dave at bogg brothers did this the first time i went last year.

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

http://www.youtube.com/watch?v=hlBlz1_RsN0

heres a vid, cannot hear the noise very well but if you listen carefully theres a sharp hiss noise about every half a second?

i have doubled checked everything firing order is correct, tried retarding it a little, connected vac pipe back up nothing, i also noticed i had some oil on the outside of my dashpot.

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

Took ny carve and plenum off to find oily petrol stuff swushing around in ny plenum?

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

Im going to say double check all your carb connections. Just to make sure, there looks to be that many of them perhaps you got one or two wrong by mistake?

All connections are ok, a Lot if them are just blocking things off like part throttle lean off

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

Have just rebuilt the engine?

Not a full rebuild but everything exept the short engine is new

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

You sure return & feed pipes are connected right? Fuel pressure? As you say, everything head upwards has been changed or revamped. I take it dizzy has not been taken out......if you replaced leads/cap, double check. If your unsure, get no.1 dtc, whip the rocker box off. Both valves closed, see where the rotor is pointing. I know it all sounds retard, but best check simple things first. :)

Fuel pressure reg is connected up fine I've double and triple checked, its brand new and set at 4PSI, yes dizzy has been out but all leads are on correctly firing order is correct I am just cleaning carb out with all new gaskets between manifold carb and plenum as we speak

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

Just turned the idle mixture screw out about 2 turns and it has cured the problem? Just a fueling issue by the looks of things lol

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

Double post

Edited by bennyy on 20th Aug, 2011.

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

Cool, good work