Unhappy choke start.

[Donkey]

Hi guys,
Your advice please.

Starting from cold, whatever the temperature, the Stag isn't happy. She'll start after two or three turns, but then needs right peddle to keep her going and is as lumpy as a high performance car. Pushing in the choke to a quarter, as I used to do, changes nothing. However, once up to temperature, she's just fine, and drives very well across the range.

I've lived with it for a year or so now, but as I'm giving her a full service, I thought I'd see if I can put it right. So, my question is:- Is the culprit the Temperature Compensators, or is the mixture to blame, or is there something else at play?

As always, I'd appreciate your responses.

Brian

[mallardstag]

Check that both chokes are operating as one of the cables may be broken or detached.

[mole42]

I have similar troubles right now, except that I mustn’t touch the right hand pedal until the engine has run for about 30 seconds, if I do it dies. Once slightly warmed there’s no problem. I’m suspecting a leak either in the dashpot or the diaphragm.
Tomorrow I plan to investigate.

[Donkey]

Check that both chokes are operating as one of the cables may be broken or detached.

Sadly not, they're both working. Any other thoughts?

[PJM Stag]

When was it last serviced? A lot of what appear to be fuel related issues end up being electrical. Renew or clean the points, check ht leads or renew the plugs or at least remove them and take a look.

[mallardstag]

Sadly not, they're both working. Any other thoughts?

Does this only happen on cold/damp starts if so it could be condensation/moisture showing up problems in HT leads, rotor arm, distributor cap, electronic ignition.

Also worth checking ignition timing, carb diaphragms and for vacuum leaks.

Only ever change one thing at a time and start with the easy & cheap ones.

[Donkey]

When was it last serviced? A lot of what appear to be fuel related issues end up being electrical. Renew or clean the points, check ht leads or renew the plugs or at least remove them and take a look.

It was serviced about 6000 miles ago, it's got electronic ignition and the plugs are fine, as is the distributor. She runs well when up to temp. If it was electrical, wouldn't it show up then as well?

[mallardstag]

wouldn't it show up then as well?

Not if caused by condensation which evaporates when the engine warms up - .rotor arms/distrubutors/HT leads prone to this if they have fine cracks in which the moisture can form overnight.

[dasadrew]

I have similar troubles right now, except that I mustn’t touch the right hand pedal until the engine has run for about 30 seconds, if I do it dies. Once slightly warmed there’s no problem. I’m suspecting a leak either in the dashpot or the diaphragm.
Tomorrow I plan to investigate.

mine's identical. To be honest, comparing other old cars I owned and own that's pretty much par for the course. After starting, I have to pull out onto a main road after about 300m - I wait for significant gaps in traffic!!

Drew

[JeffW]

Mine is as well. And oddly it is much worse with rebuilt carbs. Inexplicably with my old, untouched carbs the car would start instantly and not really need choke very much at all. It must like all the grunge in them!

Jeff

[KOY 23]

You won’t need choke if the mixture is set very rich. I think the optimum setting is around 3% CO. I had bad cold starting when 1st bought the car, one of the choke disks was the wrong way round hence not enriching the mixture.

[Stagdad]

I was playing with my stag starting today. Just tweaked the "warm up enrichment" and "after start enrichment" maps

[KOY 23]

One of the many benefits of a proper EFI system.

[mole42]

I was playing with my stag starting today. Just tweaked the "warm up enrichment" and "after start enrichment" maps

Hah! Mapping a Stag engine? You should be ashamed, Sir! You need to re-install the twin points and adjust them properly for penance.

Five Hail Marys afterwards…

[Stagdad]

Hah! Mapping a Stag engine? You should be ashamed, Sir! You need to re-install the twin points and adjust them properly for penance.

Five Hail Marys afterwards…

Soz, i would need a distributor to be able to do that.