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Triumph TR6 - Car dies when choke pushed in

My 74 TR6 has sat in the garage for about 2 months without being started. I went in abut a month ago and got it to start up without too much cranking. As it warmed up and I pushed the choke in, it just died when the choke was in about 1/2 way. Been starting is up over the past couple of days thinking it just needed some run in to loosen things up but it is still dying.

If I adjust the choke until it is just ready to stall and then push the accelerator...it dies.

It was running fine before I let it sit. Any idea what happened.

Gene
Gene Fluder

My first guess is that one of the carb needle valves is stuck closed. Maybe a rap on the side of the float bowl with a screw driver handle....
Brent B

Brent, Started typing but couldn't figure how to say that. Prolly all gummed up?
DON KELLY

Brent, Don,

Thanks. I didn't even think about tapping on the carb. Been checking vacuum lines. Hope is isn't gummed up. They were rebuilt not more than 2 years ago by professionals.

Thanks, guys.

Gene
Gene Fluder

It's a 74....no hope. Junk it. : 0
JT White

Gene - Try starting it with the air filters off. While it's running lift the carb air valve/piston one at a time. If nothing much happens that's the one the no gas.
Brent B

Oh yea - make sure the cable end hasn't slipped out of one of the chokes.
Brent B

hey Gene I have the exact problem,let me know how you made out
Ron E.

Used a carburettor cleaner ( spray and gas additive ). It got a bit better but it looks like a rebuild. I've got half a tank left so I'll run it out and see if anything improves but I am not hopeful.
Gene Fluder

BTW, I forgot to mention that I ordered the adjustment tool from TRF. It sure seems like it is running too lean so I thought I'd give and adjustment a try before ripping the things apart. However, the rebuild is tempting since the EGR control valve is on the front carb and not the back. Someone messed this up before I got my baby.
Gene Fluder

my car is a 69, it was running rich for quite sometime.Before I put it in the garage for the winter it was running rough almost like it was running on 5 cylinders when i gave it gas, at idle it was fine. I changed the diaphrams to no avail, I had to start it with starting fluid and once it started had the same problem as you,push the choke in and it stalled. I dont want to take it apart either, keep me posted
Ron E.

will do
Gene Fluder

I pitched that "space alien" as soon as I got my 74. I don't see the need to "re burn" my exhaust gasses. More then likely it wasn't working worth a damn anyway and a good tuned non EGR TR6 is going to put out less emissions the an old crappy EGR plumbed system.
JT White

Ron

The 69 has a retard valve that opens when the carbs are at idle. It is located under the formost carb. If the vac line comes off, you might get the problem you describe. I have had that happen. Yours may have been modified since though and this valve may be gone.

Gene, Ron,

Engine Timing and carb adjustments are critical and feed off each other. I found I had to go back and forth between adjusting the carb and the timing until I got the car running as per the spec.

You may need to adjust the choke cams.

Invest in a timing light, carb air flow meter, needle/mixture adjusting screw, mixture test kit (watching the combustion in the cylinder) and play with the settings until you get to spec.

I set mine 5 years ago and haven't had to touch them since. Knock on wood. (it took me I think 6 or 8 hours to get it right)

These carbs are very sensitive to atmospheric conditions as well. I can notice a difference in running on sunny warm days and hazy humid days and coolish days. You probably want to adjust them on a typical day for your geographic area to get the most consistent performance.
Michael Petryschuk

Thanks all. Just invested in the adjusting tool and the air flow meter. Saturday is coming and I'll work on it some more then.
Gene Fluder

How hard is it to turn the mixture adjusting screw? The tool seems to engage everything but it is not turning in either direction. Perhaps this is the problem.
Gene Fluder

Not sure Gene- my 69 does not have the adjusting type of needle but a fixed needle. But I believe there is a set screw- have you loosened that?
Michael Petryschuk

Gene - They should turn fairly easily, but not "loose". There could be a varnish build-up in the needle retainer binding things up. If you can't get it to rotate either way after several minutes of back & forth it's time to pull the air valve and check out the needle.
Brent B

They are free! Took your advice this morning, Brent, and carefully but insistently put pressure. Each, in turn, finally started moving.

Lots of rain today so I can't open the doors in the garage to try to tune them. It will have to wait until Friday.

I'll be back Friday night with my next whine.

Thanks
Gene
Gene Fluder

I got back to the carb problem yesterday. I've got the adjustment as rich as it will go: each carb is adjusted all the way in. When I lift the air valves, the engine stalls which the manual claims means it is too lean.

Engine now can run at normal idle RPM but very rough and still with the choke half out.

Any other "non invasive" tricks to try?

Gene
Gene Fluder

It sounds like you need some fresh gasoline. Do you trust it enough to get on the road?
Brent B

First thing I thought of. Put new gas in just after this started. Tank was almost empty because of a leak in the gas line. Car is up on jackstands right now and not road-worthy at the moment.

Have to admit that things are getting better each time I start it up. I can now get it to idle, albeit roughly, at 800 RPM. Need choke out still but I couldn't even manage that last week.

I'm becoming convinced it is gunk

Gene
Gene Fluder

Gene- e mail me.
donnkelly at comcast net
DON KELLY

Bump - Gene, did you get things sorted out?
Brent B

Gene, where are YOU?

What about syncing the 2 carbs? What about timing? what about fuel filter?

Rick
Rick Crawford

This thread was discussed between 17/01/2011 and 22/04/2011

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