Running rich part 2

[jagman1970]

Thanks for all the help. I have now reset everything as per the manual (again) and using a colourtune the mixture seems correct on plugs 1 & 6 (they're the easiest to take out). Tickover steady at 6-700 revs but after running plugs are still black and car misfires (runs rough).
I think what has happened is that I have run with the choke on and the head is very carbonated.
So, Any suggestions on doing a de-coke without taking head off. Can I soak the bores in something like Redex. or is there another way.
Thanks again for any suggestions and help.

Keith 1970 2+2

[ernie]

Hi
I have heard good reports re the Terraclean process which is implemented through a network of local workshops. It should be considerably cleaner than a decoke etc and more thorough.....I also haven't heard any reports that it damages engines....
Search for a local workshop and have a chat to them

[JimmyS]

There is a lot to be said for taking the car for a good high rpm run (thrash) to clean the engine out. In my student days, I remember a friend at the garage were I worked telling me about an elderly customer who brought a DB6 in for a service in a state of exasperation. He had taken it to a number of other places in an attempt to get it run smoothly but to no avail. The proprietor of the garage asked him what he used it for. 'The occasional Sunday drive and trip to the shops' was his reply. When checked, the carbs & timing were all set correctly so the car was chained down on a rolling road and subjected to a period of sustained high rpm running. I'm told that sorted it and the customer was delighted! About the same time, I remember a friend taking his mother's Triumph Dolomite shopping car for a brisk drive while trying to stay in front of my Escort Mexico. It was dark at the time and the glowing particles of carbon flying out of the Dolomite's exhaust pipe were a sight to behold! Being older and more sensible now, I appreciate that this is a bit of a high risk strategy if glowing combustion chamber carbon is inducing pre-ignition. Does you car 'run-on' after your have switched off the ignition?

[jagman1970]

No running on.

[PeterCrespin]

I think what has happened is that I have run with the choke on and the head is very carbonated.
So, Any suggestions on doing a de-coke without taking head off. Can I soak the bores in something like Redex. or is there another way.
Thanks again for any suggestions and help.

If the car runs, it should run well enough to burn off soot. You probably have another issue if you can't even hold sustained medium revs. You can steam clean by spraying water in at high revs but you have to know what you're doing or you can kill the engine.

If it idles fine are you sure the needles are correct spec and/or correctly fitted? Idle is the same for practically any needle as the main part is the same OD and it feeds through a different circuit anyway, but once the slide lifts the needle controls mixture. If yours is very rich once off idle with an unobstructed air filter, I'd be looking to try weaker needles (once you are certain that fuel pressure and float heights are correct).