Problem with Twin SU Rover V8 Fitted to Stag

BYS600K · Post by **BYS600K** » Sat Jan 14, 2012 3:46 pm

Hi All,

I'm new here and hoping that you'll be able to help me.

I have a 1971 Triumph Stag fitted with a Rover V8 Twin HIF 6 SU's. Unfortunately i only got to enjoy the car for a year before it failed it's MOT and one thing lead to another and it's now 4 years later. I've not long returned from Australia and decided she was a sad sight and needs to be enjoyed again.

So far we've;

Stripped, cleaned and rebuilt the SU's with new gaskets and rubbers where required.

New Spark Plugs.

New Battery.

Amazingly she fired first time with the new battery after standing still for 4 years but it was noticed that the Carb on the left bank was leaking fuel so that test stopped and i rebuilt them both (my dad always say's never to do just one if there are two of something on a car).

She was now running but it seemed to be rich and she was smoking a little so we set to adjusting the mixture to no avail.

I took out the spark plugs and they were all as black as night (only run twice) except number 4 which still looked new so i cleaned and returned them and started her again. No smoke this time but she's running rougher than bag of bolts.

I was hoping to do much of the work as possible as since returning to the UK finding work has been shall we say difficult, so money is tight.

Unfortunately i fear number 4 isn't firing at all (or worse) so any ideas you guys may have i am completely open.

RoverP6B · Post by **RoverP6B** » Sun Jan 15, 2012 8:25 pm

Which SU needles have you fitted?

To obtain an initial idle mixture point, remove the dashpot and lift out the pistons, then wind up the jet so that it is flush with the bridge. Now wind each jet two full turns down.

If there are no other problems, the engine will start and idle quite well, then you can fine tune the idle mixture.

To rule in or out a problem with the lead from the distributor to #4, swap that lead with another and see if there is any difference.

Please lets know how you go.
Ron.

ChrisJC · Post by **ChrisJC** » Mon Jan 16, 2012 1:20 pm

Have you checked out the ignition system?

Chris.

BYS600K · Post by **BYS600K** » Tue Jan 17, 2012 12:40 pm

RoverP6B - I'm not sure on the Needles but i'm assuming standard as i haven't changed anything. Also thanks for the advice i'll give that a go later on today and see if it's made any difference.

ChrisJC - Checked the ignition as far back as the Distributor but im going to switch over the leads to number 4 and see if that makes a difference. I'm told it could be a problem with the Coil.

ian.stewart · Post by **ian.stewart** » Tue Jan 17, 2012 1:17 pm

One thing you have not mentioned, The car has been stood for 4 years---- "it fired up first time" have you replaced the fuel with fresh, after this time, the fuel will have gone stale,

ChrisJC · Post by **ChrisJC** » Tue Jan 17, 2012 1:42 pm

Worth trying it in the dark to see if it's tracking from any part of the HT system.

Chris.