Club 80-90 Forums

2.1MV with Pierburg.

I've set my timing as per the guide. removing vacuum from dizzy then set revs to 900rpm, set timing to mark on rear of pulley to edge case. Except in may case, when I remove the vacuum line it stalls. So, I've raised the idle up sufficiently so I can at least set the timing, which I've now done.

But, it now idles at 1250rpm, and if I turn it down to 900rpm it stalls.

Air/Fuel Mix on carb. - I've tried it on every setting, 2 turns out, 3 turns out, 7 turns out, no difference; stalls unless I have the idle up sufficiently.

Once running at 1250rpm, if I remove the vacuum from the dizzy it will stall.

I bought a new vacuum advance for the distributor, but to no avail.

Any ideas, or previous experience of this?

BLock the end of the pipe you take off , the advance won’t work , but the vac won’t be open to atmosphere 
it would suggest your mixture is too weak if it won’t run ( albei lumpy and slow) with the vac pipes off .

Does it affect the strobe if I use a stand alone 12v power supply (spare car battery) and not the van supply?

It doesn’t affect mine , I always use a separate power supply .

 

Set air/Fuel mix screw to 3.5 turns out (anti-clockwise). I ran it up the road and back, it's goes ok, it's been much better. But it idles erratically, around 1250rpm. I can't bring it down to 900rpm using the idle screw & where it should be, as it stalls. The only thought I have is to maybe run it 'advanced' for a bit, until I can get to a gas analyser. It seems to prefer it like that. Open to advice as always.

Just by ear, this is how much advance it idles nicely at ?!

Air intake leak. Examples of where this might be or where you have had them? I mean there is only 2 vacuum pipes and mine are new. One from the air filter to the carb. One from the carb to the dizzy. I had the air/mixture screw in my hand. The o-ring looks good, not flattened.

Why did you start messing with the timing ?

What timing are you seeing with vac disconnected /plugged, and with vac hose in pace ?

IIRC there's no idle stabilisation on a 2.1MV so it should be fairly stable, if there is, bypass it

Shouldn't it be around 5 Degrees BTDC? That pictures the marks looks way off.

I started messing with the timing because it’s running really rough. I can’t set the timing as per ‘the guide’, it would just stall @ the rear pulley mark. It’s MV pistons on DG ancillaries. No idle stabilisation. I am temporarily running this much ‘advance’ just so it won’t stall, when I start it.

Where was the timing & where is it now - difficult to see from your picture / don't know what the white mark is?

This brake vacuum hose doesn’t look great, but it doesn’t leak.

I’ll spray some WD40 around the base of the carb. and pipes. Any increase in revs shows air getting sucked in.

"That much advance" is indicative I suspect of a weak mixture, so yes air leaks, including from that servo hose. Numbers are better than descriptions though.

I was starting to think blocked jets... but it could be either

Cold Carb. This should be closed but it isn’t or wasn’t should I say. Still checking for air leaks.