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Re: Poor / no running - Weber Carbs

PostPosted: Thu May 05, 2016 7:57 pm
by roblotus79
Simultaneous posting on fuel pressure @mbell :)

Re: Poor / no running - Weber Carbs

PostPosted: Thu May 05, 2016 8:42 pm
by Sea Ranch
Gizze wrote:Update from the garage......

- Took the plugs out, all of them were black . . .


They're not firing well (which may of course be obvious to you), and they are apparently getting fuel (hence the black partially-burned fuel).

I think it's ignition, not fuel (though you probably have messed up carbs as well, given the excess fuel around). Proof: you spray in that quick start stuff and don't get firing.

You think you have ignition, but those flashing light gizmos don't tell you anything but that there's some electricity flowing through the spark lead. Could be very low voltage.

Replace coil with known good unit, then replace spark leads if no success. I realize this is difficult, but having another car around to swap parts with is the best way to find out what's working.

Regards (and good luck)

Randy

Re: Poor / no running - Weber Carbs

PostPosted: Fri May 06, 2016 6:05 am
by RichC
agree with Randy.
do you have any suppressors wired into ignition system? If so, remove them and try again.
also take care if u have +ve earth car that u have wired the coil right way............. 8)

Re: Poor / no running - Weber Carbs

PostPosted: Fri May 06, 2016 8:46 am
by martinbrowning
I agree with previous replies - almost certainly an ignition problem. I had almost identical issues not so long ago on my Sprint. Changed rotor arm, condenser and coil with quality items from "Distributor Doctor" - problem sorted.
(Incidentally, I also experienced a similar problem on my Europa Special - turned out to be a partially blocked air filter. Worth checking?)

Good luck

Martin

Re: Poor / no running - Weber Carbs

PostPosted: Fri May 06, 2016 3:09 pm
by vincereynard
If you don't get a cough with the "Easy Start" I'd also vote here for ignition.

To set float height I often use those little wooden sticks available in any coffee shop.

Mark the height and dip, fuel soaks into wood and can be seen.

If it gets to much, walk away! You don't want a Basil Fawlty moment.

Good Luck
Vince

Re: Poor / no running - Weber Carbs

PostPosted: Sun May 08, 2016 2:24 pm
by Craig Elliott
I've had similar problems to this in the past - what spark plugs are you using?

The reason I ask is that I think with modern fuels in the UK you need to run a hotter plug. I use to have problems with plug fouling and the car running badly when using the standard plugs (N7Y or equivalent if I remember correctly). I started using BP6ES or equivalent and it's far far better. They can still foul up (this is on a S130/5 with Dellortos and IWR cams) in traffic or idling but will clear.

Re: Poor / no running - Weber Carbs

PostPosted: Fri May 13, 2016 4:56 pm
by Gizze
Hi,
Garage update.....
Carbs opened up and float levels checked to manual - they were within 1mm or so but adjusted anyway.
I also reduced the petrol level in the float chambers just to see if initially the carbs wouldn't be 'flooded'.
Tried starting again, but still no luck.
Plugs still wet after a few goes of starting. Now heading back into the garage.........the saga continues.....

Re: Poor / no running - Weber Carbs

PostPosted: Fri May 13, 2016 4:59 pm
by Gizze
Apologies forgot to say, now going back to review ignition aspects again. Leads, plugs etc.... :roll:

Re: Poor / no running - Weber Carbs

PostPosted: Fri May 20, 2016 7:44 pm
by Gizze
Now fitted new NGK plugs, leads, cap, rotor arm (new Condenser and coil previously fitted)
And guess what......nothing.
Refitted the spark plug flasher and also held a spark plug against the block.....now no spark/flashing.
Re-checked 12v at the coil - ok.
So I assume I've disturbed something because before at least the flasher was flashing
Will now look at the wire going to the distributor and the distributor itself I guess......may take the distributor itself out to check it out....off with the carb again!

Re: Poor / no running - Weber Carbs

PostPosted: Fri May 20, 2016 9:54 pm
by promotor
Have you fitted the points properly with the insulation block in the correct place - in the wrong place you'll get a short.

Also as has been suggested by plenty of people (for good reason) change the coil for a decent known one. I only use old coils on my cars - 45-50 years old and still better than most being made today. Impressive when you think how many times the coil field must have collapsed over its life time and still work!

Re: Poor / no running - Weber Carbs

PostPosted: Sat May 21, 2016 6:45 am
by Gizze
Many thanks for the reply - Yes I will check for incorrect wiring / shorts..... have changed the coil already and as well as a new coil I've also tried a couple of others I've had in the garage, so I'm sure the coil is ok.

Re: Poor / no running - Weber Carbs

PostPosted: Sat May 21, 2016 6:50 am
by Sea Ranch
This is exciting. A genuine auto mystery!

I know it's a pain for you, Gizze, but we're rooting for you and we know you're going to conquer!

Stay with it; you will earn the admiration and praise of many when this is solved :mrgreen:

Randy

Re: Poor / no running - Weber Carbs

PostPosted: Sat May 21, 2016 8:14 am
by promotor
Gizze wrote:Many thanks for the reply - Yes I will check for incorrect wiring / shorts..... have changed the coil already and as well as a new coil I've also tried a couple of others I've had in the garage, so I'm sure the coil is ok.


Hopefully you'll get sorted soon - it just helps to throw different ideas from many different people into the ring! Can't beat a good brainstorming event!

If you fit a ballast-type coil but give it 12 volts instead of the 9 or so volts a ballast coil needs it will overheat within 5-10 minutes, and you may even burn the points out. Is your car a ballast or non-ballast system and what type of coils are you using?

Re: Poor / no running - Weber Carbs

PostPosted: Sun May 22, 2016 7:38 pm
by Gizze
The words of encouragement are much appreciated.....the auto mystery will I'm sure turn out to be something obvious.....to those with more experience than myself!
Will check the coil, I've not seen a ballast and haven't noticed the coil getting warm. Was hoping to get in the garage this weekend but 'chores' got in the way!

Re: Poor / no running - Weber Carbs

PostPosted: Mon Jun 06, 2016 5:36 pm
by Gizze
Progress!
Sorry, been on holiday, but returned into the garage with renewed focus and determination!
Now have the car running but.........
The car will not start from cold. However a small squirt of engine start gets it going and then it runs (although very unevenly)
Once warm it starts readily again, with very little 'turning' before firing.
What have I done:
- Have now replaced: Coil, Spark Plugs, Leads, Rotor arm, Distributor cap.
- Tried the spark plug indicators and there appears to be a spark (although I take on board previous comment regarding spark strength)
- the mixture screws were wound out a lot more than the 1 or so turns the workshop manual suggested would be an approximate starting point (possibly the reason why the plugs were previously so sooted up - much too rich?).

Current status:
- There is still evidence of petrol in the air box, and I've noticed the large open hole near the air inlets (about 3/8" dia) on each carb has a small pool of petrol in them (but the engine is far from smooth and is rocking about quite a bit). I can't seem to find what this hole is for though.
- The engine now clearly needs balancing / tuning properly, as it's rocking quite a bit and the idle speed is uneven.

Was so chuffed with this 'small' success I then spent a couple of hours giving it a polish, having been close to despair now can't wait to get out on the road!

Any further thoughts, as always, very welcome
Cheers