Yesterday it purred. Today it pukes at partial throttle.

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Duggie

Duggie

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Man, I don't get it. Days ago I finally set the tune to factory spec on my stock \6. Threw in the SlantSixDan fuel line mod for good measure and yesterday the engine purred like a kitten. Today it pukes at any throttle opening and continues to puke when the throttle is open. It has a Holley 1920. I rechecked the tune, sprayed starting fluid on everything to look for a vacuum leak. I don't know if I should take a walk or wind my watch. I've read these 1920s can be a headache. Do I just need a bigger hammer?

I spent the weekend replacing the rear springs and front lower control arm strut bushings. Made an appointment to get her aligned, but at this point I couldn't drive the car to the alignment shop!

Hep me! Hep me! I've fallen and can't get up!
 
What is the chance you knocked some dirt/ debri loose when working on the fuel line? I'm not sure "stock timing" is what you want, either. And please define "puke" That slang covers a hell of a lot of ground, including emitting coolant from the overflow at some point
 
67Dart273 said:
What is the chance you knocked some dirt/ debri loose when working on the fuel line? I'm not sure "stock timing" is what you want, either. And please define "puke" That slang covers a hell of a lot of ground, including emitting coolant from the overflow at some point
Click to expand...

Fair enough. It idles okay. As soon as any throttle is applied, it stumbles and acts like water is in the gas. It isn't a stumble like an accelerator pump not working, picking back up to a smooth rpm after the blip. (I did check the accelerator pump by looking down the carb.) It's a consistent stumble like all the plug wires got scrambled, and lasts as long as the throttle is open to anything above an idle.

There could have been dirt knocked loose somewhere in the line. Anything is possible I guess. Do you think a main jet could be plugged?
 
Sure could. Filters often do not stop really fine dirt/ dust.

What all did you do to ignition. You mentioned timing Where was it and why did you change it?
 
Try disconnecting the vacuum advance hose and plug it. Then try driving the car. If it is now ok, change the distributer pickup coil. At idle there is no vac to the dist. As soon as you open the throttle vac is applied to the dist, and the pick up coil rotates, there could be a issue with the coil electrical circuit that shows up when the pickup moves. By removing the vac hose, you are testing this as no vac is applied at all.
 
Heres a good one did you change out the ignition condenser with one from the parts store? What year is it anyhow?
 
New condensers have a high failure rate, usually go out quickly, especially after a hot/cold cycle.
 
67Dart273 said:
What all did you do to ignition. You mentioned timing Where was it and why did you change it?
Click to expand...

I hadn't looked at dwell and timing since I bought it (Hey it ran!) Points were too wide. Set dwell and checked the timing. Factory calls for 2.5 deg, and it was sitting at 12 deg after I set the well.

Side note; It occurred to me this morning that the engine reves fine when the car is static in the garage but stumbles so bad on the road, I have a hard time getting it back to the garage.

halifaxhops said:
New condensers have a high failure rate, usually go out quickly, especially after a hot/cold cycle.
Click to expand...

It's the old condenser. Point contacts looked good- no pitting. It's a '64 stock \6, with a Holley 1920, slightly buggered manifold heat valve and half functional manifold choke spring. The engine was at operating temp before I pulled it out of the garage.

Thanks you guys. I'll blow out the main jet today and report back.
 
67Dart273 said:
Sure could. Filters often do not stop really fine dirt/ dust.
Click to expand...

Sometimes I think I'm too deep into the forest to see the trees.

This rubber snake was hanging out of the main jet.

jet.JPG


Thanks! :thankyou:
 
Duggie said:
Man, I don't get it. Days ago I finally set the tune to factory spec on my stock \6. Threw in the SlantSixDan fuel line mod for good measure and yesterday the engine purred like a kitten. Today it pukes at any throttle opening and continues to puke when the throttle is open. It has a Holley 1920. I rechecked the tune, sprayed starting fluid on everything to look for a vacuum leak. I don't know if I should take a walk or wind my watch. I've read these 1920s can be a headache. Do I just need a bigger hammer?

I spent the weekend replacing the rear springs and front lower control arm strut bushings. Made an appointment to get her aligned, but at this point I couldn't drive the car to the alignment shop!

Hep me! Hep me! I've fallen and can't get up!
Click to expand...
Start with the basics, read the plugs they can tell you alot.
 
69FBCuda said:
All better now?
Click to expand...

Yep, purrs like a kitten again (while hacking up a fur ball when the engine is cold). How a 1" long strip of rubber got through the needle and seat is a mystery though.

Now I can go back to looking at how the manifold well - spring choke is supposed to work. I soaked the spring in white vinegar for a day and the spring and arm off the spring look to be free. It looks like the spring doesn't have enough tension to push the choke linkage closed. What looks a spring adjustment screw is frozen tight. Maybe I'll try to wind the spring around one more turn and see what fresh Hell that develops!
choke spring.JPG
 
Duggie said:
Now I can go back to looking at how the manifold well - spring choke is supposed to work.
Click to expand...

Yours is both old and brutalised (pushrod bent improperly). Either get an original-type replacement from Old Car Parts Northwest, or get a № 1231 electric choke kit, which will bolt right on and hook right up and allow for much easier choke adjustments (since you don't have to remove it to adjust it, like you do with the original type).

Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download. And you'l find tune-up parts and technique suggestions in this post.
 
OK I am the *** that has to ask this. Have sex under the hood? How the hell did that get there? I thought I have seen most of it!
 
slantsixdan said:
Yours is both old and brutalised (pushrod bent improperly). Either get an original-type replacement from Old Car Parts Northwest, or get a № 1231 electric choke kit, which will bolt right on and hook right up and allow for much easier choke adjustments (since you don't have to remove it to adjust it, like you do with the original type).

Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download. And you'l find tune-up parts and technique suggestions in this post.
Click to expand...

I know how old and brutalized feels! I should have recognized it. :eek:

Thanks for the links Dan. I've sent a note to the supplier for the electric choke conversion and will read the tips and tricks for the 1920 when I'm sitting still.

This puppy will be a daily driver yet!
:steering:
 
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