Capri -Misfiring Fixed

For several months, my green Deluxe has been misfiring on a cold start. It seemed as if the engine was running on 3 cylinders for a brief time maybe 5 - 20 seconds & then it would just run as it should. Rarely did it start without  some misfire. Nothing visibly seemed to be astray & I had checked the choke was OK & all the leads were firmly attached.
At last, time for some action & I was hoping it was nothing major. First step was to pull out the plugs. Undid No 1 plug, closest to the front, & there was all this discolouring & gunk on the metal body of the plug. Very interesting! Next plug out & similar discolouring but not quite as much. Plugs 3 & 4 were as per normal. The tips of the plugs were all very similar & with a normal type colouring.
With a torch, I looked very carefully in the spark plug wells of No 1 & 2 cylinder & they also had a bit of rubbish. To me ,it looked like fried radiator coolant. If the top radiator hose was leaking, coolant could run down a passage in the head into the plug wells. Very interesting! The hose looked very normal but I had experienced some spraying of coolant after a couple of long runs and assumed it was the radiator cap. So, off came the top radiator hose.
On first inspection, it looked fine. I then took it out in the sunlight & after probing & pushing discovered a very small split on the underside of the hose, very close to the clamp. I then formulated this theory that each time the car was garaged after a run, the build up radiator pressure caused the hose to discharge a small amount of coolant into the No 1 spark plug well.



So, let's put in a new set of plugs (NGK-BP6ES; $20) & a new radiator hose (Gates 05-0108; $16).

After several starts, no misfiring & it runs properly from start up. It is yet to go on a long run but I am confident the split hose was the problem.