Lancia Motor Club Forum Banner
25 February, 2020, 03:54:46 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
 
   Home   Help Search Calendar Register  
Pages: [1]   Go Down
  Print  
Author Topic: Very fast idle  (Read 592 times)
0 Members and 1 Guest are viewing this topic.
simonpen
Member
**
Offline Offline

Posts: 14


« on: 29 January, 2020, 04:49:05 PM »

After a bit of a layoff and trouble finding a spark my Rallye 1.3S burst into life and went straight to almost 3000rpm. Turned it off, each time I start her the same thing happens. I have disconnected the accelerator linkage, wound out the idle speed screw, no change. The butterflies are closing. Air leaks? I have replaced the gaskets either side of the carburettor mount(s), the rubber mounts look alright, no obvious cracks., ageing. I disconnected the servo hose, revs go even higher, put my finger over the manifold take-off revs go back down to 3000. Timing is correct. I had rebuilt the carbs some months ago and afterwards everything appeared ok, she ran quite well. Interestingly she now needs no choke to start, quite cold today, started second time, straight to 3000 and quite smooth. Any ideas? Should I go back to Jaguars?
Logged
Richard Fridd
Permanent resident
**
Offline Offline

Posts: 2876



« Reply #1 on: 29 January, 2020, 05:03:26 PM »

Is the choke stuck on?
Logged

Richard Nevison Fridd
simonpen
Member
**
Offline Offline

Posts: 14


« Reply #2 on: 29 January, 2020, 05:19:58 PM »

Not that I can see externally,  I have disconnected those as well and manually yanked them to what should be the shut position.
 
Logged
lancialulu
Press Officer
Permanent resident
*****
Offline Offline

Posts: 3667



« Reply #3 on: 29 January, 2020, 05:47:37 PM »

Sounds like an air leak.... spray wd40 around to see if revs drop momentarily.
Logged

Its not the winning but taking part! or is it taking apart?
1955 Aurelia B12
1967 Flavia Vignale iniezione
1967 Fulvia HFR
1972 1600 HF
1972 1600 Fulvia Sport
1978 Transformer HF3000 Strato's replica
1979 2500 Gamma Coupe
1988 Delta 1.6GTi.e.
nistri
Megaposter
*
Offline Offline

Posts: 254


« Reply #4 on: 30 January, 2020, 04:11:57 PM »

And if you cannot detect any air leak, check the needle valves, they can become erratic in their up and down operation particulalry when the engine is not used for some time, Andrea. PS:  no need to go to Jags, you probably already have their braking system if you car is S1.
Logged

Andrea Nistri

Ardea S2
Appia S2
Fulvia GTE
Fulvia Sport 1.3 S
Fulvia Montecarlo
Fulvia Coupe 1.3 S
simonpen
Member
**
Offline Offline

Posts: 14


« Reply #5 on: 31 January, 2020, 04:46:26 PM »

I started her up and sprayed WD40 around, nowhere seemed to make any difference. I was about to take the tops off of the carbs to check the needle valves when I thought I might try some brute force. The air filter box is removed so I took hold of the rear carb and pulled it upwards and lo! the revs dropped. Tried the same with the front carb and the revs went up, if I pull the rear up and push the front carb down the revs die away dramatically, indeed the engine cuts out. I suppose this means that the rubber mounts need replacing although they look ok. Is there any advantage to the one-piece mount as opposed to the separate variety? 
Logged
nistri
Megaposter
*
Offline Offline

Posts: 254


« Reply #6 on: 01 February, 2020, 11:29:54 AM »

No real advantage in either type: essential to have a support bar under the air filter otherwise the carbs move and the spacer can crack, Andrea
Logged

Andrea Nistri

Ardea S2
Appia S2
Fulvia GTE
Fulvia Sport 1.3 S
Fulvia Montecarlo
Fulvia Coupe 1.3 S
Tindrum
Member

Offline Offline

Posts: 4


« Reply #7 on: 03 February, 2020, 04:23:40 PM »

The affect of moving the two carbs independently is merely making an adjustment that the balance screw makes.
If there are "canaries singing", in the immortal words of Harry Manning, that's a clear indication of split rubber mount(s).
If not, it probably just means a bit of expert adjustment is in order.
Speak to non-member Paul Leclercq (var1016@gmail.com)
He's very good at carbs, and Fulvias, generally.
Good luck.
Justin
Logged
chriswgawne
Permanent resident
**
Offline Offline

Posts: 1435



« Reply #8 on: 04 February, 2020, 01:37:11 AM »

I am always surprised how many Fulvias have had the carb support removed. It really is necessary.
Chris
Logged

Chris Gawne
Mobile: 07778 216552
simonpen
Member
**
Offline Offline

Posts: 14


« Reply #9 on: 04 February, 2020, 06:48:08 PM »

Tindrum has it. I couldn't understand how yanking one carb up and another down worked and decided that I must just have been moving the spindles and affecting the balance of the carbs and so revisited the balance screw; I say revisit, that may not be accurate. All much better now and I shall flog myself with some heater hose as a penance. Paul Leclercq? Is that he with a cigarette holder that worked with Barry W some years ago? It was meeting that crew that convinced me I had done the right thing becoming a Lancia owner.
Logged
Tindrum
Member

Offline Offline

Posts: 4


« Reply #10 on: 05 February, 2020, 09:20:48 AM »

Very pleased we found the problem.
As mentioned by CG, if the carbs are being run with the airbox, that's a very heavy assembly for the rubbers to support unaided. The brace below the drip tray must be adapted/utilised.
Personally, I think carbs alone aren't such a problem but, for the sake of longevity, a good idea.
(My throttle bodies are very light, so not a problem).
Paul Leclercq is indeed ex- Evolution Engineering/BWE/Italtune, as am I, to a degree, and we both learned a lot from Barry W., and Harry M. before then.
Logged
my69S1
Member
*
Offline Offline

Posts: 9


« Reply #11 on: 08 February, 2020, 01:45:21 PM »

Does anyone have a picture of the support for the air box?  I am missing mine and the parts book isn't very clear.  I would like to know what it looks like.  Thanks.
Logged
chriswgawne
Permanent resident
**
Offline Offline

Posts: 1435



« Reply #12 on: 08 February, 2020, 01:56:36 PM »

I have one spare 35mm diameter flexible carb mount in the UK in good condition if anyone needs one. No reasonable offer refused.
Chris
Logged

Chris Gawne
Mobile: 07778 216552
Pages: [1]   Go Up
  Print  
 
Jump to:  

Contact the Forum Administrator

LMC Forum copyright © 2007 - 2018 Lancia Motor Club Ltd

Powered by SMF 1.1.20 | SMF © 2006-2011, Simple Machines