Idling too quickly
Good afternoon... by heck, he's getting formal!
Haven't posted in ages, managed to fix all the recent issues with the cheque book. Except this one. Had the carbs rebuilt by my local man and now the car runs well, but soots up the plugs in no time. It's also idling at about 1000-1100 rpm. I can't adjust the idle speed because the screw isn't even touching the stop.
Had it down at the local meet the other day and the general opinion was that there was "something wrong" - but we never got to a specific diagnosis.
What worries me is that the choke is fully home and there's a bit of slack in the throttle cable. So maybe the butterflies are in the wrong place. Is that possible? Could I be running on choke all the time and pouring petrol down the bores?
All ideas gratefully received!
Haven't posted in ages, managed to fix all the recent issues with the cheque book. Except this one. Had the carbs rebuilt by my local man and now the car runs well, but soots up the plugs in no time. It's also idling at about 1000-1100 rpm. I can't adjust the idle speed because the screw isn't even touching the stop.
Had it down at the local meet the other day and the general opinion was that there was "something wrong" - but we never got to a specific diagnosis.
What worries me is that the choke is fully home and there's a bit of slack in the throttle cable. So maybe the butterflies are in the wrong place. Is that possible? Could I be running on choke all the time and pouring petrol down the bores?
All ideas gratefully received!
Malcolm
Membership no 7477
(Wakefield, Yorks)
'76 2500S Estate
Why settle for a simple solution when a complicated one will suffice?
Membership no 7477
(Wakefield, Yorks)
'76 2500S Estate
Why settle for a simple solution when a complicated one will suffice?
Re: Idling too quickly
Seems that you have 2 problems, running too rich, wrong needles or out of adjustment. As you say, butterflies misaligned.Suggest that you take it back to your repairer and get him to do a proper job which is what you paid for.
Tony.
Tony.
1976 2500 TC. converted to S specs.
Lots of bits
1999 BMW Z3.
2006 BMW 325ti.
Hopefully not needing too many bits.
.
Lots of bits
1999 BMW Z3.
2006 BMW 325ti.
Hopefully not needing too many bits.
.
Re: Idling too quickly
Yes the butterflies need slackening off and allowed to seat before fastening back up and re checking. You'll need to take the carbs off the car to do it properly.
Re: Idling too quickly
I hope that rebuild means new butterflies and axles in this case. Air leakage because of sloppy axles is a very common reason for idling too fast without being able to calm it down.
Onno Zijlstra
2.5 PI Mk2 saloon 1970 - laurel green
Vitesse Mk2 saloon 1969 (under construction) - royal blue
Saab 9 3 Turbo 2000 (daily use) - black
2.5 PI Mk2 saloon 1970 - laurel green
Vitesse Mk2 saloon 1969 (under construction) - royal blue
Saab 9 3 Turbo 2000 (daily use) - black
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- Site Admin
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Re: Idling too quickly
Hi Malcolm!
Don't forget that originally, your carbs would have had poppet valves in them. These were supposed to open on overrun but only on overrun. Over time, it seems as if the springs weaken and they can open a bit on tickover. The general cure is to replace them with plain butterflies - or solder the old ones up!
If the carbs have been rebuilt with new (plain) discs, then it sounds like they've not been centralised properly. This is usually done by leaving the fixing screws loose and letting the butteflies 'snap' shut a few times. Then do the screws up!
Mind you, your man should know about all this!
BTW, I've just sent you an email.
Cheers,
Mike.
Don't forget that originally, your carbs would have had poppet valves in them. These were supposed to open on overrun but only on overrun. Over time, it seems as if the springs weaken and they can open a bit on tickover. The general cure is to replace them with plain butterflies - or solder the old ones up!
If the carbs have been rebuilt with new (plain) discs, then it sounds like they've not been centralised properly. This is usually done by leaving the fixing screws loose and letting the butteflies 'snap' shut a few times. Then do the screws up!
Mind you, your man should know about all this!
BTW, I've just sent you an email.
Cheers,
Mike.
(South Oxfordshire)
Register Member No 0355
1971 2.5PI Saloon Sapphire blue
1973 2.5PI Saloon rust some Honeysuckle
1973 Stag French blue
(1949 LandRover was blue should be light green!)
Register Member No 0355
1971 2.5PI Saloon Sapphire blue
1973 2.5PI Saloon rust some Honeysuckle
1973 Stag French blue
(1949 LandRover was blue should be light green!)
Re: Idling too quickly
Thanks folks - this is what I rather suspected, and it looks like I'm going to have to sack my man... he's normally very good but he let me down again the other day on something else. Unfortunately, despite understanding everything that's been said it's beyond my capabilities to take the carbs off, mainly due to the fact that my hands aren't what they were - age and all that
Time to wield the cheque book again! Nuisance, that, I'm trying to save up to get the rust in the screen surround fixed...
Cheers
Time to wield the cheque book again! Nuisance, that, I'm trying to save up to get the rust in the screen surround fixed...
Cheers
Malcolm
Membership no 7477
(Wakefield, Yorks)
'76 2500S Estate
Why settle for a simple solution when a complicated one will suffice?
Membership no 7477
(Wakefield, Yorks)
'76 2500S Estate
Why settle for a simple solution when a complicated one will suffice?
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- Location:Luton
Re: Idling too quickly
if they have temperature compensators on the side they may be set open when they need to be closed at normal temperatures
held on the side with 2 screws, and sealed to the body with two O rings , the plunger inside needs to be seated closed, adjust by tighten the small nut on the bi metal strip.. its more important they are closed than exactly right. or idle speeds and mixtures cannot be set up.as they bypass air past the throttle plates
but yes check the t plates are fitted the right way round ( yes they are chamfered to seat when closed) and are centred ok
Pete
held on the side with 2 screws, and sealed to the body with two O rings , the plunger inside needs to be seated closed, adjust by tighten the small nut on the bi metal strip.. its more important they are closed than exactly right. or idle speeds and mixtures cannot be set up.as they bypass air past the throttle plates
but yes check the t plates are fitted the right way round ( yes they are chamfered to seat when closed) and are centred ok
Pete
Pete Lewis
Luton
also area organiser for herts and beds tssc.
Luton
also area organiser for herts and beds tssc.
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- Location:South Oxfordshire, UK
Re: Idling too quickly
Malcolm's is a '76 'S' so should have HS6s. Were these fitted with temperature compensators like the CD range?
Cheers,
Mike.
Cheers,
Mike.
(South Oxfordshire)
Register Member No 0355
1971 2.5PI Saloon Sapphire blue
1973 2.5PI Saloon rust some Honeysuckle
1973 Stag French blue
(1949 LandRover was blue should be light green!)
Register Member No 0355
1971 2.5PI Saloon Sapphire blue
1973 2.5PI Saloon rust some Honeysuckle
1973 Stag French blue
(1949 LandRover was blue should be light green!)
Re: Idling too quickly
Yes it does have HS6 carbs - I got the overhaul kits from Burlen - as I just specified the car then I should have got the right needles, I guess, and I would also have got butterflies with poppet valves. Probably standard spindles as well. I can live with the high idle speed, but I suspect I could be washing the bores with excess fuel, so it'll have to be fixed!
Thanks for all your comments...
Thanks for all your comments...
Malcolm
Membership no 7477
(Wakefield, Yorks)
'76 2500S Estate
Why settle for a simple solution when a complicated one will suffice?
Membership no 7477
(Wakefield, Yorks)
'76 2500S Estate
Why settle for a simple solution when a complicated one will suffice?
Re: Idling too quickly
Well... there's a garage not far from me that has a '77 Minivan so I figured they might know about this problem... and I've just got the car back. It's now idling at about 750, going like a rocket and although I haven't checked it (it's chucking it down right now) I'm assured that the idle screws are now touching the cam. I don't know what this wonderful chap actually did, but whatever it was it only took him an hour. Obviously something was out of adjustment. I may well pay this chap another visit!
Cheers
Cheers
Malcolm
Membership no 7477
(Wakefield, Yorks)
'76 2500S Estate
Why settle for a simple solution when a complicated one will suffice?
Membership no 7477
(Wakefield, Yorks)
'76 2500S Estate
Why settle for a simple solution when a complicated one will suffice?
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