32/36 DGV Weber issues!

[bnicho]

Hi,

Today I removed the stock carby from my 16R (bog stock) and subsituted a 32/36 Weber DGV 5A Manual Choke. I have quite a bit of experience with these carbs, but this has me stumped.

Problems:
- I cannot get the engine to idle below about 2500rpm and then only with the choke butterflies almost closed.
- It runs like crap when revved and backfires unless the choke butterflies are almost closed.

Basically it seems like it needs a REALLY RICH mixture to run. Which to me sounds like a huge vacuum leak.

The carb fitted straight on with a Redline adapter plate intended for a Gemini. My imported16R has a different carb spacing than local 18R-C etc. I used the original insulator block and spill tray under the adaptor plate.

The carb was stripped of all components except the main butterflies and linkages, flushed with copious quantities of carby cleaner and a good blow through with the compressor. It was then rebuilt with a new service kit, new power valve and accelerator pump diaphram, needle and seat etc. Jetting as a starting point is (Primary/Secondary) Main Jets: 140/150, Air Correctors: 165/160, idle jets: 45/50 and the standard F50/F6 emulsion tubes. The float levels are correct as per the service kit for the carb.

I'm at a loss to what the problem is. So far I have:
- Blocked off all vacuum hoses etc one by one to isolate potential vacuum leaks. No difference.
- Checked around the base of the carb and adaptor etc for vacuum leaks.
- Pulled the carb and rechecked float levels and that the base of the carb is flat.
- Examined the carb for missing blanking plugs in passages, cracks or any obvious faults.
- Checked all gaskets, the adaptor plate and insulating spacer for faults.

All suggestions appreciated!

Cheers,

[oldcorollas]

it sound slike the idle and progression circuits are blocked... so you need the choke to pull fuel from the main jets instead to run...

can you blow thru the idle and progression holes with either air, or WD40 (or whichever spray stuff you have with that long little tube thingy)??

[bnicho]

it sound slike the idle and progression circuits are blocked... so you need the choke to pull fuel from the main jets instead to run...

can you blow thru the idle and progression holes with either air, or WD40 (or whichever spray stuff you have with that long little tube thingy)??

Thanks, that sounds logical.

I'll give it a try.

Cheers,

[briney]

it seems to me to be a blocked idle jet problem. does this carb have an idle stop solenoid ? if you slip the idle mixture screw out, and give it a squirt with compressed air, there's a good chance it will fix it.

[bnicho]

Thanks, already tried that.

I've had the carby off again twice and completely blown it through three times. Still won't idle and I get backfires when I rev it.

I just did a search looking for another one and I found this thread:

http://www.toymods.net/forums/showth...ighlight=weber

This is my carby, I bought it off MAD79R who bought it off Malicia!

Notice this quote: "I also remember I was having problems with Back Firing (flames out carby) ". So there is an old issue with the carby somewhere.

I'm gonna give up on this carb for now, just keep it for spares. Anyone got another one to sell?

BTW: I'm not blaming Malicia or MAD79R for not revealing the problem, I bought the carby knowing it needed a rebuild.

Cheers,

[joecoolmk2]

haven't touched the timing at all have you? sounds like the ignition timing's out.

[oldcorollas]

i reckon.. if thats the case.. time to get a bit more serious

get some thick fishing line.. or thin metal wire, and start poking up the idle and progression holes to try and clear them.... try not to scrape inside the holes and make metal shavings, but try and clean it out a bit...

just blowing may not be enough to break up some solid particles...

also poke the holes from the top of where the carby splits etc.... basically try and make sure you have a flow path thru each hole and no blockages...

also maybe check the base of the carb for warpage which might be causing leaks?

[briney]

maybe a solvent bath ? i have had some good success with thinners. watch out for the fumes also,as old corollas said, gently try and poke through the passages, during and after soaking.

[bnicho]

Hi,

Carb is now off the car again. The base is dead flat, checked it with a straight edge. Soaking it in Kero now, but maybe I will try acrylic thinners.

I haven't dared try and poke down the passages yet, as I don't have any fishing line or similar lying around. I have some MIG wire, but that would scratch the inside of the passages.

[broken22]

an ultrasonic cleaner would clear out an blockages

[Dazza]

Check that the aux venturi isnt in backwards so the hole is blocked off

[bnicho]

Check that the aux venturi isnt in backwards so the hole is blocked off

I've had both Aux venturis out when I initially cleaned the carb and they are not in backwards.

Appreciating all the suggestions though!

[Dazza]

Is there any play in the throttle shafts. There are supposed to be seals on the throttle shafts that might be damaged or missing.

[bnicho]

Is there any play in the throttle shafts. There are supposed to be seals on the throttle shafts that might be damaged or missing.

Yep, the seals and bushes on the throttle shafts are good. No play evident.

I really thing it is an internal blockage in the carb body. No time to look at in the next few days.

[hosking1991]

the flame up through he carb is a real kent singed all me eyebrows
sorry i cant help mate but good luck with it

luke