Daft Questions..deserve answers

This week, what has been annoying me most?...

The bloody random tick over on the Taxi when hot..and the running on but we will get wound up by one thing at a time for the moment

Anyway I posted up a daft question on the CT forum asking for ideas as to why it should do it and how to fix it-I had my own theory and wanted to know what others thought-as it turned out we all pretty much agreed that heat from the exhaust manifold could be upsetting the carbs and hence the tick over whilst hot-so what could be done ? Some ideas;

• Heat wrap the exhaust to insulate it-hmm bit of a "last resort" in my book
• Reflective heat shield between the exhaust manifold and carbs -easy to do but I was sceptical it would work
• Direct cold air intake/ducting into carbs-not so easy to do whilst keeping "trumpets" on the SUs due to air box design etc

I set about knocking up a reflective heat shield (above) - please note how tidy and shed like my bench is-I used a section of 2mm thick aluminium that was kicking about, cuting two "slots" in the top edge to locate around the inlet branches, then positioned it between the exhaust manifold and carbs leaving an air gap between shield and exhaust manifold,fixing it in place with brackets and self tappers for its test run-I will revisit to make it a more permanent/robust install

Whilst tinkering in the area I thought I best check tightness of inlet/exhaust manifold nuts -first one I check I had the sickening "stripped thread" feeling in my stomach- off with the lot to remove the stud- having had my suspicions about the manifold gasket -thus I wasnt too concerned about the extra work in replacing it-see what you think was the old one leaking?

This is the stripped inlet stud

So with new inlet/exhaust manifold gasket fitted , dodgy stud replaced and heat shield installed it was time to test I took the car out for a quick five mile blast returned and left it ticking over expecting to see the idle RPM increase to around 1000-1200- as it had in the past -or at least rise and then slowly fall after "bliping" the throttle

I was pleasantly surprised to see a constant idle of 800rpm even after 10 minutes of tick over and varied throttle positions

I turned the engine off and guess what ...it ran on! but not as bad as before,so I would surmise a medium shed tinker success,next thing to have a fiddle with will be the cold air intake,possibly duct some cold air directly onto the exhaust manifold? feel free to comment with your ideas!

More Shed antics to follow..