Has anyone fitted a manual choke conversion to their E3 ?. My automatic choke does work but I still prefer manual control. We used to fit a lot of these to cars in the 80's/90's , typically VWs and Fords. As long as it can be converted back again to original I would like to see if it can be done. I guess there are universal kits available ?
Manual Choke Conversion
- Thread starter E3_UK
- Start date
So I was recently was faced with the same dilemma. My chokes were not functioning and it was miserable at cold start. I was thinking of doing the same thing as I preferred the manual on the older 2002's that I owned, simple, easy, can adjust to your liking. But it is a little bit more of a pain I heard with the dual carbs.
Are you running Zenith's or Weber's first of all? If Original Zenith's, all I did was go to a pick and pull and got very lucky I will admit and found an unmolested complete set with linkage and manifold's for $50. One of my carburetors had the bad choke, it was pretty apparent when pulled apart it was not good anymore. I can't exactly say what the givaway was but they looked very worn and the coil was badly corroded. This happens I heard in the warmer climates when owners run distilled water more than anti-freeze in the motor. We swapped one of the chokes from the set I pulled off the donor set and it worked like a charm. Starts right up and as the temperature rises, the chokes do their job. One thing I will pass along as I am not a mechanic, nor am I a tuner, but the person that did tune these and he is one of the best in the country wrote me this, "Cold start/run okay? Didn't get to fully tweak the cold idle." So, without even tweaking the cold idle, it starts and runs amazing. Like night and day. It may make more of a difference to dial it in completely if you live in a colder climate than Southern Cal (And I just noticed you are in UK so that tweak will obviously make a difference and I'm not sure how to "tweak" them. I'm sure somebody on here knows, maybe just be a matter of loosening or tightening a screw. So, I hope what I said helps, if I am wrong technically with anything I said please chime in one of you by all means, I don't want to give out false info, this was just my experience lately.
It's the standard Zenith set up I have. The automatic choke does work, my main issue is that the engine revs are too high when it starts and I can hear a top end rattle briefly until oil pressure is achieved. With a manual choke I have a better chance of preventing this. Reading the set up procedure in the manual it advises how to set the fast idle at 1400rpm but I don't see anything on adjusting the revs at initial start. Once it has fired the revs drop almost immediately to around 1400. To avoid the rattle I have to immediately kick down the throttle as soon as it fires and before it revs too high which effectively puts it off choke and then it runs very rough until properly warm. If I could adjust the revs at start up I'd be happy with the automatic choke.
That's a fast idle linkage adjustment, not the choke flap. The choke richens the mixture, the linkage contols the rpm, both activated off the metallic spring in the housing. Behind a hole in the housing there is a screw on the bottom of each carb's throttle cam that can be dialed back with a very small screwdriver. They don't make it easy but once you get the hang of it it's not too bad. Probably easier than rigging up a manual choke.
http://www.e9coupe.com/tech/zeniths/bmw1/bmw1.html#008
The top end rattle should be looked into, perhaps your timing chain tensioner needs attention.
http://www.e9coupe.com/tech/zeniths/bmw1/bmw1.html#008
The top end rattle should be looked into, perhaps your timing chain tensioner needs attention.
Thanks Steve I didn't think the fast idle setting was to blame as it does settle to the correct t 1400rpm as soon as it starts. It's just the instant it fires the revs go through the roof just for a second before dropping to 1400. I'm not sure if this can be adjusted ?.
Doh ok I didn't read your description thoroughly. So before you cold start you push the pedal to the floor once to engage the linkage then start it with your foot off the pedal?
your timing is within spec? No vacuum leaks?
Timing is set per the book. I haven't checked for any vacuum leaks but there's nothing else to suggest there might be any, it runs perfectly otherwise. I'll double check what it revs to next time I start it, maybe there's nothing wrong with it.
Mmm
sounds like one carb is pulling off prematurely; almost immediately. That's also likely causing your rough idle during warm-up.
Fast idle for both carbs engaged is higher than 1400.
Recheck the settings per the manual, individually at both carbs by manually inducing the fast idle and adjust so they both engage equally. Visually first, then by tach operating one carb.
Pull off the connecting linkage at the rear. Pull off one choke cover at a time for a visual.
Find the one that's not operating correctly.:grin:
sounds like one carb is pulling off prematurely; almost immediately. That's also likely causing your rough idle during warm-up.
Fast idle for both carbs engaged is higher than 1400.
Recheck the settings per the manual, individually at both carbs by manually inducing the fast idle and adjust so they both engage equally. Visually first, then by tach operating one carb.
Pull off the connecting linkage at the rear. Pull off one choke cover at a time for a visual.
Find the one that's not operating correctly.:grin:
Thanks for the input. Just to clarify it doesn't run rough during warmup, it only does this if I quickly depress the gas pedal as soon as it fires to prevent the revs rising too high, as I am effectively putting it off choke while still cold. If I let it do its own thing it idles smoothly on choke with revs gradually dropping as it warms as it should. I may be looking for a fault that isn't there, I just don't like how it revs so high on a cold start, can't be doing the motor much good.
No..
it's not normal.
A choke is not going to pull down if it's working right. Heat - electric and water are the two elements which control when the choke comes off.
You may have a sticking/ worn linkage.
You may have a fuel level issue.
it's not normal.
A choke is not going to pull down if it's working right. Heat - electric and water are the two elements which control when the choke comes off.
You may have a sticking/ worn linkage.
You may have a fuel level issue.
jmackro
Well-Known Member
I have a manual choke on my e9, but my solution was kind of drastic. I was running an old set of water-choked Weber 32/36's. Rather than rebuild them, I replaced them with Weber 32/36 DGV 5A's, which accept a manual choke cable.
As far as I'm concerned, the manual choke works a lot better than water or electric-actuated chokes. But I tend to like things that are dirt-simple.
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I always thought automatic chokes could be overridden by sharply applying full throttle to shut off the choke. Maybe I'm thinking of a different type ?.
Hi E3_UK
My 3.0S starts exactly the same way as yours , even including a rattle unless I crank it over to get the oil pressure up first.
I read through the Instruction manual that the car came with and it appears to be starting and behaving correctly, even revving at 2200 rpm when cold.
It is doubly annoying for me because mine has automatic transmission and I need the revs low before I can (sympathetically) engage gears.
In one of the above posts it gives a link to a description of how to adjust the fast idle ( my Haynes manual also explains it the same). I havent done this yet but I am considering it.
By the way - hello from a fellow UK E3 owner, I'm in South Yorkshire.
My 3.0S starts exactly the same way as yours , even including a rattle unless I crank it over to get the oil pressure up first.
I read through the Instruction manual that the car came with and it appears to be starting and behaving correctly, even revving at 2200 rpm when cold.
It is doubly annoying for me because mine has automatic transmission and I need the revs low before I can (sympathetically) engage gears.
In one of the above posts it gives a link to a description of how to adjust the fast idle ( my Haynes manual also explains it the same). I havent done this yet but I am considering it.
By the way - hello from a fellow UK E3 owner, I'm in South Yorkshire.