Punkworks Choke Substitute

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Not sure how fuel injection does cold start enrichment. IF it adjusted the mixture with feedback, then this might work with FI, but if it just over-fuels based on temperature it wouldn't be effective since the FI would be over-fuelling anyway.

Anyway, my car has a carb, and seems to be finding the current not-summer Taiwan temps (around 10C, Jings!) to be a bit cold. Don't think my actual choke does anything.

I made a prototype a while ago with a disposable lighter but didn't really need it in the prevailing temps. This one is a bigger "pre-production" version.

Simply made with a large 25NT refillable lighter and a 10NT intravenous butterfly line. Lever the metal flame shield off, pull the torch nozzle (seen on the left) off, remove the piezo-electric igniter (seen on the right), fit the IV line over the gas outlet and replace the flame shield, which gives you something to put a wedge under (I used a cable tie) to hold the button down.

Igniter is perhaps a tiny fire/explosion risk but more importantly it seems to delay or prevent shutoff, despite being spring loaded. Might be worth adding a return spring, perhaps derived from ball-point pen innards, but it seems to work without it.

My dialysis set derived restriction guage/decoker described elsewhere has an injection port on it so I could stick it in that, but I might want it independent so will probably route it directly through thr top of the air cleaner.

Of course not many carbed cars left here, but there are lots of small capacity motorcycles. A gas choke wont cause the same fuel dilution.
 
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That doesn't provide NEAR enough fuel.

Something like this would be 10,000% easier to make work.

edce6a98a2ad598e2b1923fb6736ea78.jpg
 
Originally Posted By: Linctex
That doesn't provide NEAR enough fuel.

Something like this would be 10,000% easier to make work.

edce6a98a2ad598e2b1923fb6736ea78.jpg



Don't believe you.

I've run the engine using a blowtorchas as an emergency work around when the carb was really dysfunctional and it was difficult and perhaps a bit dangerous to hook up. It was also visible, which could theoretically lead to cop trouble.



For this application it doesn't have to run on the gas. It just has to be helped to start on it, and maybe helped initially to run on it.

For starting the gas delivery rate isn't critical, since it'll pool in the intake tract until the engine is turned over.

For running I havn't attempted to quantify how much gas is required,(how much does a choke effectively richen the mixture? dunno) but every little must help,bearing in mind that, unlike petrol, the gas is all volatile and the temperatures here never get close to freezing.
 
Originally Posted By: clinebarger
Your choke can't be that hard to fix......Take a picture of the carburetor & we may be able to help you.


Its an 80's carb. OF COURSE it can be hard to fix.

Its got loads of vacuum tubes and gizmos on it which I don't understand, and when it started giving me severe drivability problems I disconnected them all and plugged the ports with chopsticks (bit of local colour for you there)

I've re-instated vacuum and centrifugal advance but so far havn't felt motivated to restore anything else. Its got a high idle and may be running a bit rich, perhaps because the idle needle valve or its seat are damaged.

When/if I get my colortune working so I have some feedback I MIGHT mess further with it.
 


Seems to work, in that it started easily. Still needed to be kept going with the accelerator for a bit but the time to stable idle seemed shorter, though I havn't timed it before and after.

However, it wasn't cold even by Taiwanese standards today, and I forgot which way the flame adjuster went on the lighter so I don't know if it was full on or not.

Took it for about a 30k run including some freeway. In retrospect I should have done this first with an almost empty disposable lighter in the same location to see if it exploded, and I should have got some of these (lost in translation) fire extinguishers, but anyway I got away with it this time.

4a015c19c660e.jpg
 
Originally Posted By: Linctex
That doesn't provide NEAR enough fuel.

Something like this would be 10,000% easier to make work.

edce6a98a2ad598e2b1923fb6736ea78.jpg



I attempted some sums here, which also describes in more detail using a blowtorch so I could move the car when it was REALLY broken, and some argy bargy on the relative safety implications. I think you don't get the pictures unless youre logged in though.

http://bangernomics.editboard.com/t696-neochoke1

I havn't measured the gas output from this bigger lighter version, but clearly it still wouldn't be nearly enough to run the engine on.
 
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