HI All.new here and looking for some advice . I have a 1973 GMC K1500 . I installed a new edelbrock 1406 with a edelbrock high rise dual plain intake

[ThumbSoar]

What are some tips and tricks on setting up idle and timing . I have my timing set at 10* idle right around 750 . But as soon as I connect my vacuum advance my timing jumps to 16* . I can adjust the idle down so that there is no vacuum at idle . But then it barely runs in gear . The other odd thing is when the vacuum line from the distributer is connected to the ported vacuum side of the carb , when I hit the throttle I can see the timing retard about 4* which is what I think is causing the stumble under load .

Any help or advice would be fantastic !

 

[MelbGMC]

Hi Thumbsoar, try these links

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which vacuum line is for timing on an edelbrock carb? - Third Generation F-Body Message Boards

Tech / General Engine - which vacuum line is for timing on an edelbrock carb? - there are 2 vacuum ports on the front, which one is for the timing?

www.thirdgen.org

 

[Camar068]

Can the title be any longer? Anyway, Good video and there's plenty of info on the forums about the 1406 if you utilize the search function. Think of the search function like Google

 

[ThumbSoar]

Ok thanks I'll check it out

 

[Babs]

You must be registered for see images attach

 

[WFO]

Welcome from the Texas Panhandle.

 

[Corvette Ed]

Welcome to the forum from East Tennessee.

 

[75gmck25]

I suggest using the full-time vacuum port on the Edelbrock. The timed port will work but was really only useful for emissions controls. I prefer the extra timing at idle.

- disconnect and plug the vacuum line that you pull off the distributor.
- with idle speed down to about 600-700 rpm, set base timing to 12 degrees BTDC ( I have to assume you have verified the TDC pointer is mounted correctly). If the idle goes up as you advance timing, set it back down to ensure you have 0 mechanical advance.
- lock down the distributor and rev the engine up to about 2500-3000 rpm, and verify you get about 18-20 degrees additional timing (32 total) from mechanical advance
- while at idle, reconnect the full vacuum line to the distributor and verify you get about 18 degrees from vacuum advance

Now disconnect and plug the vacuum advance line again, and go through Edelbrock’s process to set mixture and idle. I prefer to have the idle in drive at about 750 rpm because it can handle my A/C compressor cycling on. This means it usually idles at about 900-1000 in Park, which is a little higher than recommended.

Edelbrocks can be sensitive to transition slot exposure, and sometimes need a step up spring swap to prevent off-idle bog.

 

[potent rodent]

welcome , first get your timing set and then go to carb setting, looking at the carb from the front use the port on the dr side its for vac manifold this is for your vac adv

 

[1973c10]

Welcome aboard

 

[Camar068]

Welcome! Just an FYI and no offense, but "1973 GMC K1500 Edelbrock 1406 highrise" would have sufficed. Better forum etiquette. You'll get more replies and views than with a full sentence in a new post "Topic".

Again, welcome.....cya around.

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