Club 80-90 Forums

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.

most likely stale fuel

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.

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

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

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

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

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

uniqueinteriors wrote: ↑11 Feb 2024, 13:47 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

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!

uniqueinteriors wrote: ↑11 Feb 2024, 21:15 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

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

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?

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

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.