Running rough after sitting for 3 months

[uniqueinteriors]

I have a 72 bay window with a 1600 twin port engine with twin 40 dellorto carbs. I did an engine rebuild last year and cover 400 miles last summer so just running it in at the moment.
Was running really well. So I went to move it on Wednesday and it was struggling to idle and when I tried to rev it it would bog down and backfire. Any ideas! I haven't changed anything on it. Thought it might be the cheap fuel pump so changed it to an oem vw one and no change. Totally baffled by thus one.

[davidoft1]

most likely stale fuel

[DoubleOSeven]

Just let it run for 30 mins at idle, get it hot. The tappets just need some oil and it’ll settle. Then give it a good run, it’ll be ok.

[uniqueinteriors]

Could it be worth redoing valve clearance I kind of think it feels like that.

[Aidan]

don't try adjusting the valve clearances till it's had a proper run as if any lifters have drained down they need warmth and oil pressure to refill hence clattering when left and cold symptoms

[davidoft1]

Don’t “fix” random stuff , the fuel is pretty much certainly stale , put a few fresh gallons in and run it for a while

[uniqueinteriors]

I've never had this problem before. I've got half a tank of petrol can I put the fresh in with it?

[uniqueinteriors]

Right so I've tried it on fresh fuel today and there's no change what should I try next?

[davidoft1]

Right so I've tried it on fresh fuel today and there's no change what should I try next?

How long have you now had it running

[uniqueinteriors]

It won't stay running its popping alot won't rev and won't idle as I said its only done 400 miles since the rebuild. I don't want to rev the gutts out of it incase I damage anything!

[davidoft1]

It won't stay running its popping alot won't rev and won't idle as I said its only done 400 miles since the rebuild. I don't want to rev the gutts out of it incase I damage anything!

You need to run it longer

[uniqueinteriors]

Why run it longer I'm not sure I understand what this is doing

[uniqueinteriors]

So I've been back working on the bus today. So I've eliminated that it's nothing to do with fuel. But it would appear it's only running on cylinders 2 and 4. It's a rebuilt engine with brand new heads. I have a 009 with electronic ignition that's been in the bus since 2006. As its 1 and 3 which are on the opposite side of the distributor is it possible that the electronic ignition module has come to the end of it's life?

[Aidan]

have you double checked the leads are connected in the correct firing order ?
Have you checked that when the rotor arm is pointing at timing mark for number 1 cylinder on the edge of the disi that he engine is actually at the compression point for number 1 cylinder, that is both valves shut following the inlet valve opening and closing ? It is possible to install the disi with the disi drive 180' out of position

[uniqueinteriors]

Yeah aidan this is all present and correct. I am now thinking that its the magnet on the dizzy drive for the electronic ignition. Ive ordered a new one and points and condenser to test it for that. My mechanic seem to think it was definitely to do with ignition. I will get this swapped out this week and let you know if it sorts it.