autopia

Thanks. I suspected that even a little dripping was too much......but just had to ask...... Actually, I was able to get to some of the primary passages w/o taking the top/choke-chamber off. It's my daily commute chariot so I can't tear it apart and really clean it up until the weekend. BTW - Now that it's idling at low rpm ok again, I noticed that the idle mixture screw no longer has much effect - even when lightly closed it will still run (although barely) whereas it should really sputter to a stop. Maybe this is somehow related to the primary venturi nozzle still dripping a bit - but I can't explain it. thanks

Thanks Dr Dlex - you're on to something! The hitachi dcp-306 on the subaru is somewhat different than the dch-340 on the isuzu. The slow-jet is inside the air-horn/throat and not accessible w/o removing the choke/air-horn chamber. Nevertheless, there were 2 air bleeds I could spray with carb cleaner: the primary main air bleed jet and an adjacent hole which appears to be another air bleed - maybe for the slow jet. Anyway, squirting either of these forced cleaner out the other as well as out the primary venturi nozzle (so they're all connected).....and, and......it can now idle again at a low rpm. The venturi nozzle is dry at idle (as I think it should be) but at higher rpm (open throttle) the venturi nozzle is now mostly passively spraying gas but still dripping somewhat, although not nearly as badly as before. Maybe I just dislodged some dirt/obstruction a bit. I'll next try removing the idle mixture screw and the anti-dieseling solenoid so I can spray and/or apply vacuum to all the primary passages and see if that clears any dirt. I'm assuming that the venturi nozzle should never drip (only spray) under all rpm/throttle openings. Is this right? thanks!

I've also got a hitachi carb (dch340 on a different car) and guess what?......It's also dripping gas at the primary venturi/nozzle. The symptoms are the same: can't idle except at very high rpm. I disabled the anti-dieseling-solenoid (removed the plunger) and it had no effect. The fuel bowl level is ok and I also haven't located any externel vacuum leaks yet. Any ideas? I'd like to eliminate the simple stuff before rebuilding the carb. thanks btw - I've been driving with one foot on the gas and one foot on the brakes when coming to a stop......hope I'm not the one behind you at a stop light.