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wangdango
11-29-2009, 11:17 AM
ok-
carbs are rebuilt, installed, car starts right up on full choke, then when full warm (choke still out, car rpms rise to 3,000). Put choke all the way in, car rpm's drop to 500 rise to 1500 and back to 500....... Then the car eventually quits. Go to restart, cranks over, and over, and over, then fires but still, "hunts up and down." What is up with these carbs? I have had huge success in rebuilding, SU's, solex carbs, etc...... JUST NOT THESE!!!! HELP ME WHILE IM STILL SANE!
thanks
Ed

poolboy
11-29-2009, 11:27 AM
Yeah that sounds terrible. When the engine has warmed up, pulling the choke out should make the engine stumble and want to die, not speed up "choke still out, car rpms rise to 3,000".
I have to ask this. When you replaced the diaphram (if you did), were you mindfull of the index (locating) tabs on the diaphram and the corresponding slots in both the air valve and the carb body ?

3798j
11-29-2009, 11:52 AM
I'm mentioning this because of your comment of "hunts up and down".
Years ago, on my GT6, I traced the same "hunting problem" to a tear in the intake manifold gasket.
I think it occured because of a backfire through the carbs. Hope I'm not misleading.

wangdango
11-29-2009, 12:01 PM
Yes, was mindful, and did get the diaphram tabs in place (they are new also), intake gaskets are also new and not torn..... AND, it does backfire thru the carbs....and, yes, was also mindful on the orientation of the slots in the air valve and carb bodies.... Other ideas?

tdskip
11-29-2009, 12:07 PM
Not much fun when it does that I bet.

What float/jet did you use when rebuilding it?

martx-5
11-29-2009, 12:14 PM
Backfiring back through the carb usually indicates retarded timing, vacuum leak, and/or too lean a mixture.

Check the timing first. Then look for the vacuum leaks. Some carb cleaner sprayed around the intake can help locate any leaks.

Edit: Also make sure that any of the vac lines you took off are back in the right places.

tomshobby
11-29-2009, 12:40 PM
AND, it does backfire thru the carbs

Also can indicate leaking intake valve.

poolboy
11-29-2009, 02:52 PM
Weak mixture, possibly the needles and adjuster have become unthreaded, plug wires not in firing order...Just throwing things out.
Oh yeah..a blocked or otherwise float chamber vent. They are on the left side of the carb pointing toward the firewall.
Inadequate fuel delivery from fuel pump. A blocked fuel tank vent line.
I better stop "just throwing things out" until you get caught up.

poolboy
11-29-2009, 02:54 PM
One other thing, that is if you replaced the needles. If you did please go to www.6-pack.org (https://www.6-pack.org) and go to the Mechanical section and do a search for the "FAT NEEDLES" topic.

wangdango
11-30-2009, 11:14 AM
rebuild kit came from VB, the by pass valve kit from Moss. I have ALL of the vac lines off/plugged. No EGR in place either (but the holes also plugged). Basically, all the emission stuff is off. The distributer is/was vac advance, and is plugged now. I guess, my BIG a question is, removing/capping all this CRAP ok? I am a big fan of, "less is more." And really like the look of an engine w/out all this xtra crap.

I am going to see if the car runs better w/ an electric fuel pump running on a 5 gallon container of gas. I really doubt this will fix anything. I also went with the "stock" needles. Also timing is dead on.

What should the by pass valve be set at?
How about the needle setting, where should I start. Right now they little washer is flush with the piston deck.

Thanks everyone, hope I am getting closer....
Ed

wangdango
11-30-2009, 11:15 AM
Wires are also ok....

poolboy
11-30-2009, 12:27 PM
There's one nipple that should never be capped off or plugged and that's the ones on your carbs that ventillate the float chamber when the engine idles.
They are on the left side of the carb close to the air box mounting flange. They point toward the firewall.
If you have them capped off, remove the cap and leave the nipples/vent open to the atmosphere. If that's it, you'll see an immediate improvement.

poolboy
11-30-2009, 12:34 PM
What should the by pass valve be set at?
How about the needle setting, where should I start. Right now they little washer is flush with the piston deck.

Thanks everyone, hope I am getting closer....
Ed
The TBV, Pick a # between 8 and 11 CounterClockWise turns from the screw having been turned fully ClockWise beforehand.
With the metering needle, you have only 3 threads to play with. So go 1 1/2 turns CCW from fully CW for start, but you might expect to go back CW a half turn or so, but you'll be close enough to start with.