I can't drive 55 (1 Viewer)

[cruiserpilot]

How do I confirm and fix that?

The transfer case lever is the short one on the right, there should be a placard right on the glove box door
2H - 4H - 4L
Pull that lever back to the left and forward to the 2H position. It will look like it's way to the right if it's in 4LO

If this doesn't actually do anything, then I suspect the linkage is broken, and if you take the cover or boot off
you will see down in there and know fairly quick if it's buggered.

I just noticed you are in Austin. Call AJ ajsyotas.com He's the best there is. He will have you sorted out in a few minutes.

 

[MatthewMcD]

With respect to determining is the vacuum advance is working.

I have run the engine with a vacuum pump on the carb vacuum hose. When I pull vacuum, I hear the advance happen.
With the engine off I have visually confirmed that the distributor plate moves under vacuum.

How do I confirm that it's working correctly under load? I could connect the vacuum gauge with an in-line tee and check the value when running at speed, but that won't tell me that the timing is advancing.

 

[pb4ugo]

Don't lock the hubs. Put the range shifter in 4 hi and 1st gear and drive, then stop and move the shifter to the right to 4lo. You should notice the vehicle will go slower and take more rpms to go the same speed as b4. It will be noticeable. If there's no difference you may have a problem with the shifter and possibly it's stuck in low range.

 

[MatthewMcD]

The transfer case lever is the short one on the right, there should be a placard right on the glove box door
2H - 4H - 4L
Pull that lever back to the left and forward to the 2H position. It will look like it's way to the right if it's in 4LO

If this doesn't actually do anything, then I suspect the linkage is broken, and if you take the cover or boot off
you will see down in there and know fairly quick if it's buggered.

I just noticed you are in Austin. Call AJ ajsyotas.com He's the best there is. He will have you sorted out in a few minutes.

The linkage is intact and it moves through 2H-4H-4L fairly easily.

I have tested that on jack stands and on dirt.

 

[MatthewMcD]

Don't lock the hubs. Put the range shifter in 4 hi and 1st gear and drive, then stop and move the shifter to the right to 4lo. You should notice the vehicle will go slower and take more rpms to go the same speed as b4. It will be noticeable. If there's no difference you may have a problem with the shifter and possibly it's stuck in low range.

Thanks, hubs are unlocked (both pointing to 2x4). I am confident it's been in 2H, but I will triple check after I get the tach installed and test drive it.

 

[pb4ugo]

With respect to determining is the vacuum advance is working.

I have run the engine with a vacuum pump on the carb vacuum hose. When I pull vacuum, I hear the advance happen.
With the engine off I have visually confirmed that the distributor plate moves under vacuum.

How do I confirm that it's working correctly under load? I could connect the vacuum gauge with an in-line tee and check the value when running at speed, but that won't tell me that the timing is advancing.

Your description pretty much confirms your vacuum advance is working properly. Next remove the cap and see if the mechanical advance is free and working as I described in an earlier post.

 

[MatthewMcD]

Your description pretty much confirms your vacuum advance is working properly. Next remove the cap and see if the mechanical advance is free and working as I described in an earlier post.

That's on the list. This is the list so far:

• Tachometer
• Carb Secondary Circuit
• Throttle cable and accelerator pedal adjustment
• Choke cable clean and adjust (I need to do this anyway...)
• Timing measurements
• Compression
• Transfer case shifter
• Distributor mechanical advance

 

[clrussell]

Flat road, 4th gear, foot on the floor, 45-48 MPH. The revs sound high, but I'll report back with data after I install the tach.

Thank you for the clarification

 

[pb4ugo]

I'm not sure a Rochester dual jet has a secondary function. I think both barrels are tied together.

A couple of those are quick and easy checks without any real tools unless theres a problem, such as confirming wide open throttle, checking mechanical advance and hi/lo range operation.

 

[RevISK]

@MatthewMcD
You can borrow my timing light if you want from today until Sunday.

I’m leaving at 11 to go grab a transmission for the 62 then heading to Jimmy’s for an install.

Text me if you want my address to come grab it.
I’ll leave it on the porch.

Ian

 

[RevISK]

@MatthewMcD
You can borrow my timing light if you want from today until Sunday.

I’m leaving at 11 to go grab a transmission for the 62 then heading to Jimmy’s for an install.

Text me if you want my address to come grab it.
I’ll leave it on the porch.

Ian

This is the one I have. The advance function is nice as is the RPMs for timing and tuning. You have a vacuum gauge, yes?

Advance Auto Parts - Down for Maintenance

 

[RevISK]

This is the one I have. The advance function is nice as is the RPMs for timing and tuning. You have a vacuum gauge, yes?

Advance Auto Parts - Down for Maintenance

Accidentally replied to my reply…

 

[Green Bean]

Matthew:
Maybe research “paperclip test”. As I understand it, it allows you to test if your secondary is operating. Shoot, I don’t know if it even applies on your carb setup, but just thought I’d toss it out there. Good luck. As always, take what I say with a huge grain of salt. Good luck!

 

[MatthewMcD]

This is the one I have. The advance function is nice as is the RPMs for timing and tuning. You have a vacuum gauge, yes?

Advance Auto Parts - Down for Maintenance

Thanks, I'll borrow one while I wait for mine to arrive. Yes, I have a vacuum guage.

 

[MatthewMcD]

Matthew:
Maybe research “paperclip test”. As I understand it, it allows you to test if your secondary is operating. Shoot, I don’t know if it even applies on your carb setup, but just thought I’d toss it out there. Good luck. As always, take what I say with a huge grain of salt. Good luck!

I'll have a look. When I rebuilt the carb, I verified that the various circuits were patent. I'll check it again.

 

[MatthewMcD]

I'm not sure a Rochester dual jet has a secondary function. I think both barrels are tied together.

A couple of those are quick and easy checks without any real tools unless theres a problem, such as confirming wide open throttle, checking mechanical advance and hi/lo range operation.

It's the Rochester Single Barrel "B" or "BC" carb as far as I can tell.

 

[mrboatman]

I got money on #3 on your list. You’re not getting wide open throttle when peddle is on the floor.

 

[RevISK]

I know what it is but @MatthewMcD came by my place so…

 

[pb4ugo]

I'm glad ya'll figured it out.

 

[RevISK]

I'm glad ya'll figured it out.

We diagnosed it quickly but I didn’t have time to offer much help.
Had to boogie to Rowlett to snag a transmission.
Hopefully Matt can work out the why of what’s going on relatively easy.