dual carb issues, Solex 32 PDSIT 2/3

[daos]

so.. i'm having problems with a dual carb set-up on my 69 fastback (converted from FI by PO), would really appreciate some trouble-shooting input.

- starts easily but will not idle at all
- jumps straight to fast idle after starting. runs for a while then revs reduce gradually until it dies
- lot of coughing/backfire from the right hand carb

i've adjusted valve clearance, points and static timing. dizzy is a 009 (copy).
also removed and thoroughly cleaned carbs, re-installed and set idle & volume according to manual. i did re-use the existing (not so old) manifold gaskets, should prob change those.

after than no amount of adjustment seems to make any difference. giving it some throttle bumps the revs up with the same result as before - fast idle then dies. can only keep it running with constant tweaks of throttle, otherwise it dies.

seems to run quite rough at lower revs (maybe this is the 2 cyl idle?) but ok at higher revs.

also checked & cleaned the plugs, all four were black and sooty/dry.

next on my list is to check for vacuum leaks (balance pipe & manifolds), check firing by removing plug cables, & do a compression test. also considering just changing plugs and plug cables, although there is decent spark on all four.

haven't had the car long so i don't know about the general engine condition. any thoughts on what else i should look for?

[Mike Fisher]

Sounds like your electric chokes might be the problem? Disconnect them and see how the car idles/runs without the chokes. The chokes can be adjusted/repaired when necessary.
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69 FI/AT square Daily Driver
66 sunroof,67,70,71,71,71AT,72,72AT,73 Parts
two 57 oval ragtops sold
'68 Karmann Ghia sold

Society is like stew. If you don't keep it stirred up you end up with a lot of scum on the top! - Russ_Wolfe/Edward Abbey

[ataraxia]

Check for vacuum leaks first - I had a similar problem and it seemed to be the majority of the issue.

Chase one issue at a time - otherwise you'll just run in circles replacing parts that work just fine.

[daos]

thanks mike and ataraxia for your input.

latest development - started with disconnecting the auto chokes and managed to get it to a stable idle, a little fast but better than anything up to now. interesting, they work ie. springs look healthy, elements heat up and open the choke flaps so not sure why they should be a problem after that. i'll try reconnecting them and see what difference that makes.

also checked for vacuum leaks and found nothing so that's eliminated.

a more serious issue though - still running a little rough with vibration from the left side, so checked the firing and found #4 is doing nothing. it has spark so something else is amiss. there is also heavy oil leakage from the base of that cylinder, something is clearly not 100%.

was definitely not planning to pull the motor but if it's not something that can be solved in situ..

[Mike Fisher]

I had 1 bad electric idle solenoid on my Solex's that caused a weird loping kind of running problem. Disconnect the solenoid wire & brush it on its connector. You can hear it 'click' if it's good. Bug solenoids will work for replacements.

P.S. Better buy a compression tester to test all 4 cylinders.
_________________
https://imgur.com/user/FisherSquareback/posts
69 FI/AT square Daily Driver
66 sunroof,67,70,71,71,71AT,72,72AT,73 Parts
two 57 oval ragtops sold
'68 Karmann Ghia sold

Society is like stew. If you don't keep it stirred up you end up with a lot of scum on the top! - Russ_Wolfe/Edward Abbey

[1rabbit1981]

[ataraxia]

[daos]

i'm open to any and all input.

solenoids - are we talking about the idle cut-offs that stick out the side of the carbs? i don't have those. the only electrically operated part is the auto chokes - which appear to be functioning. here's a pic of the set-up (prior to cleaning):

dead #4 cylinder is a concern though. any thoughts on that? compression test is definitely on the to-do list.

[daos]

compression and leak down tests reveal an exhaust valve leak on #4. so i'm guessing either stuck - which would be nice - or burnt and not sealing due to overheating.

[pedro sainz]

[pedro sainz]

[daos]

pedro, thx for the feedback.

carbs are now completely cleaned. now i need to fix the #4 cyl issue, then come back to the carbs.

manifold balance tube is installed, was off when i took those 'before' pics.

[daos]

well, got the engine out and heads off, this explains the total lack of compression in nr4 :