Lotus Elan

New member introduction and stromberg fast idle question

PostPost by: Sbarron » Sat Sep 22, 2012 8:38 pm

Hello, longtime lurker, recent member.

I have recently purchased a 69 S4 with federal stromberg and emisions equipment intact. I am having a problem with fast idle when warm, the idle will level off at 3k. When I take off the small vacuum tube from the most posterior carb (closest to the passenger side cabin), it settles down and responds normally. I made this association after I was admiring the engine and noticed the vacuum tube was off; when I renconnected it, the problem began. It does not seem to matter if the front carb has its vaccuum tube connected or not. With the tube off, the car idles at about 1200 rpm, still a little high.

I have used the search feature and found similar problems but I am too green to even know if they apply to me.

For background, the car was more of a show car with little regular use. Does not drip any fluids, and, I checked, all are full. Water pump seems to be functioning well and no dripping. No smoke form the exhaust. The engine bay looks like it came from the showroom. It has lived its whole life at about mile (Colorado) above sea level and is now at sea level in Louisiana. I just changed the plugs and they were dusted with dry carbon, meaning rich mixture i think. I believe it has an adjustable carb needle, ony because it came with the adjustment tool and list of carb numbers hand written on a sheet of paper dated 1980. I need the choke to start even in 100+ degree F temps. The motor stays at reasonable temps however.

I have, this week, aquired the Workshop Manual, Lotus Twin-cam, and Buckland's book. I have a colortune and a unisync on the way. As this is my first carbureted automobile I am still a lot lost.

My biggest fear is doing something and not being able to recover as there is little in the way of support in North Louisiana.

As for me, I am pleased to be an Elan owner and a memeber of this group. Over the last year or so I think I have read at least part of every topic. I have always wanted an Elan and love Lotus. I have an Elise to drive but wanted the Elan for the challenge. I entered into Elan ownership with the same feelings I did when I became a husband and a father, euphoria tempered with fear.

Thank you for considering my carb problem.

Scott Barron
Posts: 14
Joined: 09 Feb 2012

PostPost by: Matt Elan » Sun Sep 23, 2012 2:32 pm

Hi Scott and welcome -
While can't help with the query (my Stromberg Plus 2 is undergoing a serious restoration as it was in bits when I bought it) I was wondering if you could send me some pictures of your emisions equipped engine bay - I'm writing a book on the elan and need some shots of just such an engine bay with the cross over pipes and the inlet manifold, but cars still equipped are few and far between! So if you could I would apreciate it and would acknowledge you in the book of course. I've PM'ed you with my email address.


Matthew Vale - Classic Motoring Author
1968 Plus 2 - Somewhat cosmetically and mechanically modified
1969 Plus 2S - Currently undergoing nut and bolt restoration
Visit me on matthewvale.com
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Matt Elan
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PostPost by: pharriso » Tue Sep 25, 2012 8:59 pm

Hi Scott, did you buy this car - http://cgi.ebay.com/ebaymotors/ws/eBayI ... 837wt_1156?

If so congratulations, it looks beautiful!
Phil Harrison
1972 Elan Sprint 0260K
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PostPost by: Sbarron » Tue Sep 25, 2012 11:51 pm

Yes. Thank you.
Posts: 14
Joined: 09 Feb 2012

PostPost by: m750rider » Sat Sep 29, 2012 1:39 am

It sounds like you a dirty throttle bypass valve. Take it off, clean it thoroughly, and put it back on. See if that helps.


1969 S4 SE
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