34 ADF Jetting Questions

[AJFiat]

So I've been looking through the various posts on jets for the 34 ADF Carb and of coarse running into a bunch of different results so wondering what people actually have and what they are running for jets.

In my case I have a 1979 with a single plane intake, 4-2-1 exhaust, and emissions and air pump all removed. Automatic transmission with the Chinese 34 ADF carb. Not sure on jets yet as that's my next step and hence the question. While it runs with the factory Chinese jets the idle is a bit erratic and even with the secondary idle stop screwed out if I put my hand over the secondary at idle it does speed up then starts dumping fuel and runs slower.

As to what I found btoran suggested Brad said this for a stock 34 ADF.
http://www.hwww.fiatspider.com/f15/view ... f&start=15
Idle: 47/90
Main: 120/140
Air: 145/180
Emulsion tubes: f11/f75

karhawk had these listed as default
http://www.hwww.fiatspider.com/f15/view ... DF#p254643
Stock jetting on Fiat 124 sport models 1756 engine, 49 state car:
main jets 1.25 and 1.40, idle jets 50 front 60 rear, F74 emulsion tubes, air corrector jets 1.85 and 170,pump jet .50, float level 6.5mm.
Idle: 50/60
Main: 125/140
Air: 185/170
Emulsion tubes: F74/F74
Accel pump: 50

And nanonevol had these values for a 1977
http://www.hwww.fiatspider.com/f15/view ... F&start=15
Had it running good with this
Idle: 55/80
Main: 120/140
Air: 180/170
Emulsion tubes F20/F73
Accel pump: 45

And last posted this
Idle: 55/80
Main: 140/125
Air: 180/170
Emulsion tubes: F20/F7
Accel pump 50

[Nanonevol]

I think every car is going to be different but you could use the results you found as a starting point. Perhaps you could measure the unmarked Chinese jets and compare the emulsion tubes to labelled ones.

[AJFiat]

If I find someone with the tools I'll get them measured. I'm hoping to use your baselines to order up a few sizes to test with.

I found my main problem was probably the idle jet and idle control solenoid. From what I read at the time you could just run without it. But since nothing else has been helping I grabbed the one off my old ADHA carb and it's idle jet and pulled the plug that the Chinese one had in it with there jet and swapped them out and the thing idles steady now, doesn't stumble when stopping, and only drops 400 rpm or so when I put it in drive compared to probably 800 rpm before.

The Chinese one also had a rubber gasket as opposed to the solid washer the original idle control valve had on it so I don't know if maybe the Chinese one wasn't seated enough or too much or what.

Visually I can't tell the difference between the two jets. And I didn't see any part numbers on the old one either but it looks like for the ADHA it should have been 55.

Either way I'm a happy camper that it's at least driveable again. Seams to be a little sluggish still but also it's an automatic.

[rebar1111]

I just went through that process and here is what I found using an O2 sensor in the exhaust.
2L engine with 1800 head and intake with Weber 34ADF and 421 downpipes. 40-80-40 reground cam. No smog equipment. Manual transmission. Ambient air @ 65deg F. Eng temp @ 185 deg F. Timing @ 10deg BTDC.
Results were A/F between 14.0 and 12.5 from 1000 to 4000RPM

Primary Secondary
Idle Jet 60 80
Main Jet 130 140
Emulsion tube F2 F5
Air correction Jet 145 180
Syncro Air Flow @ Idle 20 2

Some times it is tough to find the exact conditions you are looking for.

[rebar1111]

I just went through that process and here is what I found using an O2 sensor in the exhaust.
2L engine with 1800 head and intake with Weber 34ADF and 421 downpipes. 40-80-40 reground cam. No smog equipment. Manual transmission. Ambient air @ 65deg F. Eng temp @ 185 deg F. Timing @ 10deg BTDC.
Results were A/F between 14.0 and 12.5 from 1000 to 4000RPM
************************Primary *********Secondary
Idle Jet *******************60**************80
Main Jet******************130*************140
Emulsion tube***************F2*************F5
Air correction Jet************45*************180
Syncro Air Flow @ Idle********20**************2

[rebar1111]

Sorry. The primary air correction jet should be 145 not 45.

[AJFiat]

Sorry I forgot to say thanks before. I'm hoping to finally get back on this project and double check what mine are set at. Are you still running the same jets with yours?

[SteinOnkel]

Hey guys,

I'm also in the Chinese 34ADF camp. The supplied idle jet is far too small, so is the one from my 32ADF. The chinese jet is ??? and the oem weber is .50

I'll be moving to .60 next, per the recommendations here. Thanks, very helpful.