transit mk1 1977 v4 2ltr misfire.

[caldwelld]

Hi, Have been restoring 1977 MK1 V4 2LTR .Engine was running ok before restoration of the body. Engine was not touched apart from being cleaned up and painted. It now has a misfire on no 1 and no 4 cylinders. New plugs,points and condenser.coil checked, distributor cap changed.Rotor changed Have switched the no3 and no4 plugs around, no difference. Changed the lead on no 4 ,no difference. Spark is weak at no1 and no 4 plugs. When these leads are removed temporarily it makes no difference to the engine running. compression test done on 1 and 4 cylinders and is ok. ht leads and lt leads checked and ok. I put in the old plugs for 1 and 4 cylinders. NO change. Have run out of ideas. Can you help

Don

[baconsdozen]

I would be tempted to see if changing the actual leads moves the misfire (ie swap No1 lead for no 3 and see if 3 then misfires) It sounds obvious but check the firing order make sure 1 and 4 haven't got swapped over.Check the distributor shaft for play and and check the points gap on all four cam lobes.

[dumper]

Have you got plug leads right or has some one had the distributor out and put it back in and timed it up on no4 and not number no1 this was a common mistake back in the day

[conrod]

Could be worn distributor bushes. Grab the top of the distributor shaft, and see how much sideways deflection it has. Try opening the points gap up a little bit and see if that fixes it. The bush will wear in the direction opposite the points, as the points put a little sideways pressure on the shaft. The bush wears in an oval shape, and the points don't open much on one side as the other. Common in any points distributor with high mileage!

[caldwelld]

Hi Chaps, got it sorted. NO 1 position on distributor was not correct despite the rocker pointing towards this one when timing marks were lined up . A strobe light would have highlighted this .We also put the leads on anti clockwise instead of clockwise. The firing order is still 1 3 4 2.
Many thanks for your help
Don

[baconsdozen]

Fords numbering of the spark plugs caused many a problem over the years.