Quote:
Originally Posted by Laird Scooby
Are you sure yours is a Weber? Fairly sure they were all Solex and/or Pierburg-Solex on the 340, especially with the anti-diesel valve.
If it is a Weber, it's fairly simple to remove the idle jets (they screw into the side of the carb at the top of the venturi usually) but the main and air correction jets will need the top half of the carb body lifted off and a new gasket (preferably) fitted.
The main jets are normally accessed from within the float chamber and are at ~45deg angle from vertical at the bottom of the float chamber adjacent to the venturi they serve. The air correction jets sit in a drilling that connects via the emulsion tubes with the main jets which also draws the fuel up and into the "spray bar" (can't remember the correct name for these, Auxiliary Venturi i think but could be wrong) that sits in the actual venturi.
All fairly simple and easy as long as you're methodical on a Weber. Solex are a French manufacturer so expect some Gallic influence but usually a similar construction, might find the jets aren't removable and are cast in the housing though.
Hopefully it's my first suspect of condensation, especially as you've already tried the jet clearing trick.
https://www.carb.parts/pdf/Exploded_...4_DMTL_USD.pdf
That link is useful as it shows the exploded view giving a good idea where everything is. |
Thanks for the above. Well, the carb is a Weber, says so on it! Otherwise I would not know!
Started engine again, same rough idle.
Thoughts I'd take out the anti-dieselling valve, tested it again, works. It has an O ring seal on the threaded bit, it looked a bit compressed, so put another on as well, took the advice and did not tighten valve up much. Started engine, went up to about 2000 RPM (I had days ago adjusted it up to stop car stalling). Unadjusted idle screw, probably to where it had been prior to this problem, engine idled nicely at about 900 RPM. Continued running engine for about 20 min, all seems OK. I can't really understand this!
I will probably take the car for a good run tomorrow and report back.
Some boring pics of 340 carb below.
DSCF0220 by
A60man, on Flickr
DSCF0221 by
A60man, on Flickr
DSCF0222 by
A60man, on Flickr
DSCF0218 by
A60man, on Flickr
DSCF0219 by
A60man, on Flickr