34 adf performance issues

[Torxx]

I just installed a new 34 adf, 1800 intake, no more emmission equip. '79 spider 60k miles

We have been working on tweaking timing and adjusting the carb, but the performance is poor so far. The car bogs when you give it gas, and in general not very responsive.

Vac lines (2) checked out

i thought the 34 adf was a straightforward upgrade. any ideas?

[So Cal Mark]

is it a brand new carb or used/rebuilt?

[Torxx]

New out of the box. $400

[bandit]

Hey Torxx


When i did my 79 Spider it was a good improvement over the stock carb got rid of the Vac Secs and all the other
crap from that horrible thing . I can feel a power gain and it runs great no jet changes needed . Was yours purchased
from a Fiat Vendor ? i was wondering if maybe the Jets need some playing with but i'm sure you did that already .


Daniel

[Torxx]

The guy from Redline(Weber distributor) said it is very unlikely to be a jetting issue. I am having problems getting the idle circuit to sync. If you turn down the engine speed via the carb or the timing, below 1200 rpm, the engine dies. No clunking or struggling, it's just like you turned the key off. You can't get the engine to struggle to run, it just shuts off, kind a like it's not getting enough fuel??. Our next step is to take the carb apart and clean it. We didn't put a fuel filter in the line yet and we did see some sediment below the float (not real bad though). I am hoping that is the issue.

[So Cal Mark]

ohhh, no filter is a bad, bad thing! It could be a clogged idle jet. Your engine will run on that idle circuit to nearly 3000rpm. I'd remove the idle jet and blow through it. Then you can also check the size of it

[Torxx]

Yes we will examine and clean the jets and make note of the size.

Just curious, wouldn't it be safe to assume that the jets are ok from the factory, being that is a new carb that is installed on many a spider like mine with only basic mods (no cam change)? Wishful thinking on my part maybe?

[bandit]

Hi Torxx


Just trying to get a better ideal of what your car is doing when you step on the gas lets say your doing
15 mph does it bog then after a sec or 2 it starts to accelerate or is it bogging all the time when you floor
it . Is it just when you first step on the gas ?
If you had some junk flow into the carb since the filter wasn't installed at first, you may have clogged a jet maybe ?
try using one of those clear fuel filters so you can see the gas .

A couple things to check on the low performance part but not really related to the bogging issue have someone
step on the gas pedal wide open with the car off while looking down the carb to see if your butterfly's are open 100%
your linkage may need adjusting the butterfly's should be standing up at 12 o clock wide open .
Next time you post a reply can you include some RPM notes with a little more detail as to what and where the engine
bogs and where it stops ect ect .

BTW i just read the other post where you had asked me about the swap i'm sorry i didnt reply i did not see it till
now .

[bandit]

he guy from Redline(Weber distributor) said it is very unlikely to be a jetting issue. I am having problems getting the idle circuit to sync. If you turn down the engine speed via the carb or the timing, below 1200 rpm, the engine dies. No clunking or struggling, it's just like you turned the key off. You can't get the engine to struggle to run, it just shuts off, kind a like it's not getting enough fuel??. Our next step is to take the carb apart and clean it. We didn't put a fuel filter in the line yet and we did see some sediment below the float (not real bad though). I am hoping that is the issue.

Sorry didn't read this part before posting

checking the Idle Jet and the solenoid is the connector attached
or maybe it is stuck, even though its a brand new carb anything can happen when parts sit around for long periods
of time . They can seize but you can free them up by unscrewing the solenoid then taking a small punch or pick by
hand and pushing the jet shaft to see if it is free not much pressure is needed nor is there much travel on them .


Daniel

[Torxx]

Do you recoginze the part pictured below.?

After hours of testing, disassembling and cleaning a brand new carb, extensive vacuum testing (actually did a smoke test), removed the new carb and put the old carb back on, all with no improvement with idle issue. As a passing thought we decided to check the electrical components that we replaced when the engine was put back together, i.e., the plugs, plug wires, dist, cap, rotor, pickup, and control module. The control module was the fist thing we tried and it turns out that was the root of the evil. Put the old one on and presto.

That’s great news, after all that. As a bonus I get to do a good comparison of the orig. Carb performance versus the 34 adf, before we put it back on for good.

[Torxx]

International Auto Parts was nice enough to send me a new module, even though I bought it over a year, ago. Bad news is the car won't start with that one installed??? weired.

[Torxx]

Conclusion to my new 34 adf saga. It was a comedy of errors or oversights while trying to set the car up. The high idle was due to the bad control module, backfiring at high speeds was due to incorrectly placed plug wires, and bogging was due to accidentally switching the jets when we took it apart to clean it, while trying to figure out why it would not idle down..

She's puring like a kitten now

[So Cal Mark]

thanks for the update, congrats on getting the car running properly