27-11-2017, 10:02 PM
(27-11-2017, 09:13 AM)Hugh Barnes Wrote: Sorry, I've been away for a while, only returning this weekend. The last change I made was to replace the twin carbs with a single carb set up with a replacement manifold and an SU carb scavenged from my Cabriolet. The upshot of that was no change in behaviour. So that eliminates carbs in any way.
I also did a compression test and got a reading of about 85psi from each cylinder. I didn't know what reading I would get, but the fact they were all pretty much equal was a good sign. So no issues with bores/pistons/valve timing (nor should there be as it is a newly rebuilt engine that has done 2-3000 miles).
I hate to say it, but I am coming to the conclusion it may be stale petrol! After all the work I've done, that's pretty much the only thing left. The fuel in the tank probably dates from the summer but I had not considered it as a possibilty as only a week earlier the car had run perfectly. Upon reflection, the previous time it ran was during the day on a warm'ish autumn afternoon, the time the fault appeared was a cold evening. Maybe that was enough...
I shall be trying fresh fuel this week, but if that doesn't resolve it, I really will be stumped. I will report back...
Hugh,
I would think that 85 PSI is low for a recently rebuilt engine - if the CR is around 6 I would expect over 100.
Cheers, Tony.