The Triumph Dolomite Club - Discussion Forum

Hi all

I have now had my 1978 sprint now for about 10 months and enjoy every minute of driving it.

Today I gave it a service changed and topped up the fluids renewed the oil and air filters and adjusted the timing to 16 btdc, which has made it pull and drive a lot better and it fills crisper to drive.

The thing is that I cannot get the idling below 1000 rpm, I have wound the idle adjustment screws right up so they are not touching the linkage and also slacken off the choke so this is not affecting it.I have had this fault since I purchased the car.

I run the car on Shell V power petrol , I hope you can help me solve this fault because apart from this it drives great.

I have set the ignition as below:-

16 btdc

Spark plug gap 40 thou

Standard air filter

Piranha electronic ignition

I also have a vacuum gauge fitted and at idle (1000rpm) it reads23.

Air leaking in somewhere? Spray carb cleaner round the mounts, and shafts in the carb etc. If engine revs change you have your leak.

I would guess that part of the throttle cable / linkage is stopping the carbs closing down properly. There is an easy to follow section in the BL and Haines manuals about how to set these up correctly - hopefully you have access to one - or else someone here may be able to post one up for you. I would start by going back to basics and resetting everything.

Your advance is quite high, but if you are setting/measuring this at 1000rpm, it could be anything at usual idle. It is usually 10-12 at idle, with later cars at 10 rather than 12. 40 thou plug gap is okay I suppose too for electronic ignition (I usually use 35). Doubt either would be responsible. Oil in the dashpots is up to level? I think at 750rpm my vacuum is around 10 on each carb when balancing them. 23 is high but probably 'normal' at 1000rpm. Plug colour is the same between front an rear pairs?

You need to remove the restriction so the carbs can idle before trying any tuning.

Running at 16 BTDC means you will end up with piston damage from detonation.

12 BTDC tops....

Jonners

All the factory workshop manuals are available to download HERE

thanks for your reply's i am away for a few days and will have a look when I get back and let you guys know how I get on