All the PI components on my car have been reconditioned and the linkage replaced by a new, still underslung, type. After being quite poorly installed by a local Triumph specialist, the linkage was disassembled yesterday by a TR6 owning mechanic and reassembled correctly. I have a good spray pattern from all injectors and the inlet manifolds are reasonably balanced (less adjustment on this linkage). We took the car for a run and after a couple of miles the idle revs started to build, eventually hitting 5k by the time I found a place to pull over. The throttle rods had elongated with the heat, but only causing a couple of mm movement, not enough to raise the idle more than a few hundred RPM. The throttle wasn't sticking and the both chokes were off. We let the engine cool for half an hour and fired it up again, idled correctly for a couple of seconds then up to 3k RPM at which point I shut it off.
I'd had a similar issue last week, however that time I stopped the car when it was idling at 3k RPM and noticed a leaking injector, had the car recovered and replaced the injector, I hadn't used it again until yesterday. We have sprayed WD40 all over looking to see if we have an air leak but nothing found, we have retightened inlet & exhaust manifolds too. The timing appears to be correct and, before the revs went crazy, the car was running well, better than it has since I bought it. Our thoughts are that the Metering Unit must be the cause, the mechanic did comment that the exhaust looked to be rich when I started the car up. Does it sound like the MU could be the cause?
NB: The car has a Phoenix manifold and single exhaust system fitted so there is a lot of under bonnet heat
Edited by iani, 10 June 2018 - 08:19 AM.