After I noticed that small amounts of fuel leaked from one of the floats on my Tricarb I replaced all the valve needles in May this year. That cured the leak and the car continued to run well.
About a month ago the car howeve started to run very rough and lost power. The problem was intermittent, it came and went, so I suspected that the ignition was the culprit and replaced disty cap, leads, plugs and condenser, but the problem remained. I tried disconnecting one lead at the time, but that did not yield any conclusive evidence. A compression test showed good compression in all cylinders (10.4 - 10.9 bar, around 150 - 160 psi) on a cold engine, so no valve train issue (I suspected a stuck lifter).
I then opened the float chambers on all three carbs and saw that the fuel level was very low on the middle one. It turned out that one of the new needle valves had a tendency to get stuck and wouldn't open, so the car ran on two carbs. The hole in the brass seat didn't seen to be round all the way down, so depending on how the needle was positioned it would stick.
Just something to remember to check if someone encounters a similar problem. It may have been a bad batch from SU (altough the two other ones I purchased do not have the same problem). I am happy that I found the problem before putting the car away for the winter (we had a second frost night yesterday). :cold:
About a month ago the car howeve started to run very rough and lost power. The problem was intermittent, it came and went, so I suspected that the ignition was the culprit and replaced disty cap, leads, plugs and condenser, but the problem remained. I tried disconnecting one lead at the time, but that did not yield any conclusive evidence. A compression test showed good compression in all cylinders (10.4 - 10.9 bar, around 150 - 160 psi) on a cold engine, so no valve train issue (I suspected a stuck lifter).
I then opened the float chambers on all three carbs and saw that the fuel level was very low on the middle one. It turned out that one of the new needle valves had a tendency to get stuck and wouldn't open, so the car ran on two carbs. The hole in the brass seat didn't seen to be round all the way down, so depending on how the needle was positioned it would stick.
Just something to remember to check if someone encounters a similar problem. It may have been a bad batch from SU (altough the two other ones I purchased do not have the same problem). I am happy that I found the problem before putting the car away for the winter (we had a second frost night yesterday). :cold: