Pinto Missfire & no vac advance

[matthew h]

Blatman

After driving home I don't know what the hell it is........... It runs ok up until 3500 rpm most of the time, but then it won't run well at any rpm, tt feels like a missfire, but it isn't, it kangaroos but at no set rpm. The best way to describe it is when you initial start a pertol mower. It is backfiring louder than ever! The garage think the carbs are letting in air and they don't rate them anyway as they are not a match pair.

Sorry its not very technical!

[Blatman]

Ignore the "not a matched pair" thing, it's a red herring. As long as they have the same jets/chokes etc etc, then it won't matter.

Backfiring suggests timing.

Rough running with carbs could be so many things, but I'd start by making sure they are properly balanced. Also make sure the chokes are secured in place. Webers are known to shake loose the small bolts that hold the chokes in place allowing them to move and cause all sorts of wierdness.

Also check the fuel pressure and check for air leaks.

Final simple check is to make sure that the carbs haven't been done up too tightly. This will also cause all sorts of wierdness. They need to be clamped up enough to prevent air leaks, but they must be able to "flex" a little on the mounts.

[ghtwscc]

Couple of things that may be worth checking. Firstly I remember hearing a while ago that one of the major ign parts manufacturers was having prolems with its rotor arms becuase the plastic was changed to the wrong spec, such that as it warmed up it became conductive and caused missfiring. If its not been changed its got to be worth a go for only a few quid. Second try the car without the airfilters (for the min time poss). On my mini I had the problem where the enging would not rev above 3.5k. After replacing plugs, leads, points, etc I evenually tracked it down to a blocked k&n. It visualy looked clean, but actualy was clogged solid with tiny particles. Good luck!

[matthew h]

Took the carbs off last night and they are going to WGT in Middlewich to be serviced, etc.

I have always admited my lack of mechanical ability, but really enjoyed myself last night!