BT7 Stalling

[fishyboy]

Hi all,
My BT7, which I've owned for 32 years, has developed an annoying problem this summer, which I am struggling to solve.

The car starts fine and runs well, but after 30 mins or so on a drive the car wants to stall everytime the car comes to stop. I assume the problem is either spark or fuel related. There is never a problem with restating the car after the stall or when the car was traveling at speed so I've sort of ruled out fuel evaporation (not previouly an issue for my UK based car) or fuel starvation in my own mind (perhaps a mistake). The car ticks over nicely at idle when I start my journey but wants to stall when I finish.

I am running a traditional points set up on the car.

Does anyone have any suggestions before I start trouble shooting?

Thanks
Phil

 

[bob hughes]

You could have a look at the low tension wire between coil and distributor, I had a break in mine, it was a temporary loss of connection at the dizzy end, the engine would just stop after about 20 minutes of driving, then after around 10 minutes I could start it again. On examining the connection the wire was broken in half just after the spade connection, it was just the insulation holding everything together.

You could also have a look in the float chambers to see if they are clear of dirt.

Best of luck



Bob

 

[NutmegCT]

Just a thought - when did you last check the warm (low speed) idle setting? (Making sure the throttle linkage is fully released, and not binding somewhere.)

Tom M.

 

[BN6_L1232]

Phil-I had a similar problem, and the cause was the float set up on the rear carb. You might want to check the float settings and check/clean the filter screen at the Banjo fitting.

I suggest you change the gaskets at the banjo fittings. Peter.

 

[fishyboy]

Hi all,
Thanks for the replies.
Took the car out yesterday and the same problem occurred after about 10 miles. With the car at home I took the tops off the float bowls, checked the filters and made sure the floats were working and set at the correct height. Started the car again and it still started to want to stall so I decided to screw out the Slow Idle valves until the car would run without stalling. Perhaps the there is a problem with the condition of the slow idle screws (ethanol damaged the rubber tips?). Next time I'll remove and inspect.

I will give the car a run out over the next few days and see if things have improved. Probably time for a carb rebuild during the winter.

Thanks
Phil

 

[NutmegCT]

Phil - thanks for keeping us posted.
Tom M.

 

[LarryK]

When it cuts out and stalls, feel the coil; if hot, replace it. Or wires loose at coil.

 

[bob hughes]

Phill, as a matter of interest, what carbs are you running on - the thermo type or just the HD ?
You could check the coil, do you carry a spare?



Bob

 

[fishyboy]

Thanks fellas for the replies.
The car is running on twin SU HD6 carbs, which I last rebuilt about 10 years ago.
I always carry a spare coil in the trunk/boot. I shall swop the coils next time if the problem persists and the current one is hot.
If it was a problem with the coil, why would it only express itself at idle?

Thanks
Phil

 

[LarryK]

I had a coil problem once. Drove to work and saw black smoke, car dropped off and died. Restarted immediately and finished the drive to work. Did this for three days, happened when just getting out of Village limits. Both ways. Felt the coil and found loose wires from the heat. Refastened wires, as they were slip ons. Everything returned to normal until in a few days coil was hot and started to leak. Replaced coil. Did the diagnostics one thing at a time until final fix.