1977 Bus - a little chuggy

misszora · Post by **misszora** » Wed Jul 23, 2008 10:48 am

Hello there,

Since the major cleaning and restoring of Miss Zora's engine I've noticed a slight chugging when I let up on the gas a bit. I feel this mostly in second and third gear. In addition, every once in a while I feel it on acceleration in second but not very often. I've noticed that she idles kind of fast but very smoothly and solidly.

Has anybody experienced this? or know what it could be?

I am adjusting her valves tomorrow - more follow-up - as well as check on the idle speed. I do have a dwell meter - yay! And on the coil, is the positive terminal the one with the green wire connected to it? thanks!

spiffy · Post by **spiffy** » Wed Jul 23, 2008 10:55 am

To aid in confusion with the color of wires (which a PO might have changed), the dizzy has + and - signs right by the terminals.

misszora · Post by **misszora** » Wed Jul 23, 2008 10:59 am

spiffy wrote:To aid in confusion with the color of wires (which a PO might have changed), the dizzy has + and - signs right by the terminals.

Much easier to figure out. thanks!

dtrumbo · Post by **dtrumbo** » Wed Jul 23, 2008 11:19 am

Your coil is hooked up right. Terminal 15 is for the wire coming from the ignition and for the wires going to your backup lights and your heater blower relay. Terminal 1 is where the green wire for the condenser and the white wire for the ECU connect.

That said, the red wire has a very questionable crimp connector on it. I can't say that's what's causing your problem, but you might as well take care of flakey electrical connections as you find them.

misszora · Post by **misszora** » Wed Jul 23, 2008 11:22 am

dtrumbo wrote:
the red wire has a very questionable crimp connector on it. I can't say that's what's causing your problem, but you might as well take care of flakey electrical connections as you find them.

couldn't hurt to address it.

bus71 · Post by **bus71** » Wed Jul 23, 2008 11:29 am

The wire to the distributer should go to the - terminal which may also be marked #1. The terminal marked + or #15 on the coil should have the wire from the ignition switch and idle solinoid, backup lights, etc. Sometimes a rich idle mixture or fouled plug can cause the problem you describe. Sounds like you are on the right track with valve adjust, etc. Good luck! PS your pic of coil looks correct.

misszora · Post by **misszora** » Wed Jul 23, 2008 11:33 am

bus71 wrote:The wire to the distributer should go to the - terminal which may also be marked #1. The terminal marked + or #15 on the coil should have the wire from the ignition switch and idle solinoid, backup lights, etc. Sometimes a rich idle mixture or fouled plug can cause the problem you describe. Sounds like you are on the right track with valve adjust, etc. Good luck! PS your pic of coil looks correct.

Cool. thanks for the input. I really love the fact that I have such a huge support group!

Westy78 · Post by **Westy78** » Wed Jul 23, 2008 4:58 pm

I'll second the off mixture possibly causing the "chug". I've had the same thing before on light throttle. Can't remember if it was a lean or rich condition though.

misszora · Post by **misszora** » Wed Jul 23, 2008 5:07 pm

Westy78 wrote:I'll second the off mixture possibly causing the "chug". I've had the same thing before on light throttle. Can't remember if it was a lean or rich condition though.

I have my "Colin diagram" but can't quite remember which way does which.

I need to listen to her and watch the dwell meter. Maybe it will come back to me - we dealt with that last summer and didn't go over it again this year since we had much bigger fish to fry.

Westy78 · Post by **Westy78** » Wed Jul 23, 2008 5:15 pm

If you're adjusting the black cog wheel inside the AFM, counter clockwise will richen the mixture, clockwise leans it. Same with adjusting the potentiometer. If you are adjusting the idle mixture (small allen head bolt in the AFM) counter clockwise or "out" will lean the mixture.

Make sure you mark where you start if you go messing with the black cog. I'd leave the potentiometer alone for now. The idle mixture most likely won't have that much affect on the chug.

misszora · Post by **misszora** » Wed Jul 23, 2008 6:27 pm

Westy78 wrote:I'd leave the potentiometer alone for now. The idle mixture most likely won't have that much affect on the chug.

I will leave the potentiometer alone because I don't know what it is.

misszora · Post by **misszora** » Wed Jul 23, 2008 7:30 pm

Plan of Action:

>>Adjust valves first thing in the morning.
>>Take Miss Zora out for a spin around the neighborhood.
>>Turn off warmed up engine.
>>Attach dwell meter (rpm for 4 cylinder engine).
>>Start engine to check idle speed.
>>Adjust accordingly per Bentley manual (Ch. 10, Sec. 5.1)
>>Pray.

There hasn't been an issue with the fuel mixture before but her engine is really different now. She's lost pounds of gunk and grime, she has cooling flaps and properly attached ducts and new parts. She seems more sensitive.

hambone · Post by **hambone** » Wed Jul 23, 2008 7:51 pm

That's normal for a refreshed engine, once you finally get it dialed in you're gonna be really surprised and happy.

misszora · Post by **misszora** » Wed Jul 23, 2008 8:00 pm

hambone wrote:That's normal for a refreshed engine, once you finally get it dialed in you're gonna be really surprised and happy.

Good. I was hoping that might be the case. It feels pretty good to know that I can just go out and do that stuff now.

chitwnvw · Post by **chitwnvw** » Wed Jul 23, 2008 8:38 pm

misszora wrote:
hambone wrote:That's normal for a refreshed engine, once you finally get it dialed in you're gonna be really surprised and happy.
Good. I was hoping that might be the case. It feels pretty good to know that I can just go out and do that stuff now.

Sometimes 'dialing in' can go on for quit a while. But it will get better if you keep plugging away.

Itinerant Air-Cooled

Itinerant Air-Cooled

1977 Bus - a little chuggy

1977 Bus - a little chuggy