Disconnecting the advance to idle???

BangkokDean

BangkokDean

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The only way to get the 383 with the 750 carb to idle was to disconnect the vacuum advance???? What am I missing here?? It seams to run OK with out the advance hooked up but WTF...........
 
73 Mike said:
Are you sure the timing mark on the damper is at TDC?
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Everything is new and the pointer was set to TDC. Tomorrow i am going to take the old distributor out of the 350 and install in the 383 as it was working just fine.At first we used the old edelbrock 650 carb and it idled all over the place so we pulled the intake to see if there was in intake leak but that was not the problem then we disconnected all the vacuum hoses including the advance it started idling better them installed the lines one at a time and the advance line seamed to be the problem. The vacuum at the base of the carb idling is 15 so that should be OK. The motor seams to be running rich as there is a strong gas exhaust smell.:suicide:
 
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OK here is what I have today. I checked TDC and it is spot on.I set the timing at 12*, The engine seams to run and idle with the vacuum advance disconnected 750 rpm but when i turn the A/C on the idle goes crazy even with the A/C idle solenoid kicking the idle up to 800rpm. Remember the Sanden 508 was on the old 350 and there was no problems. I have requested advise from Lars so maybe he can help me. BTW the new cam Edelbrock 7102 has 10in of vacuum at idle with the A/C on and 13-15in vacuum with out the A/C on???? If this don't get solved soon I am thinking of putting the 350 back in the car, at least you could drive the car.:cussing:
 
My suspicions are that the vacuum can is "hunting" with the low vacuum. Which vacuum advance can are you using?
 
big2bird said:
My suspicions are that the vacuum can is "hunting" with the low vacuum. Which vacuum advance can are you using?
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I was just reading the paper posted by Lard "Specs and facts for GM distributors" So I need to ask you what is a vacuum can? Also Lars mentions in detail a vacuum advance control unit?? What is ported or manifold vacuum to the distributor?

The distributor is a new Malory from summit. I have the vacuum advance disconnected now to get it to idle with the A/c off initial timing is 12*. it seams to run and idle fair until I use the A/C. My friend thinks the problem is my cam just having 10in of vacuum with the A/C working?
 
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The "vacuum can" is the vacuum advance control unit - they are one and the same. Vacuum Advance Control Unit is the correct technical name for it. Most people just call it the "vacuum can."

The paper you are reading explains in detail the requirements for the Vacuum Advance Control Unit based on engine vacuum levels.

E-mail me for my paper on "Vacuum Explained" if you would like a complete briefing on ported, manifold, and venturi vacuum:

[email protected]

Lars
 
lars said:
The "vacuum can" is the vacuum advance control unit - they are one and the same. Vacuum Advance Control Unit is the correct technical name for it. Most people just call it the "vacuum can."

The paper you are reading explains in detail the requirements for the Vacuum Advance Control Unit based on engine vacuum levels.

E-mail me for my paper on "Vacuum Explained" if you would like a complete briefing on ported, manifold, and venturi vacuum:

[email protected]

Lars
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E-mail sent
 
Well today the motor is idling with the A/C on at around 850 and 800 with out the A/C. This was possible with the valued guidance of Lars. Boy it is great to have him here and willing to lend a hand to his friends. Thanks Lars i am extremely great full for your time and assistance. For those that have not received a copy of Lars paper on setting the timing you must get it.
Maybe Lars can post it some time.:beer:
 
Hi

I didn't know that there are still Vette engines around not tuned by the Lars's timing method.

Rgds. Günther
 
Yeah, I think every keyboard should have the letters to my name laid out in sequence from left to right in the top left corner of the keyboard. It would make it easier for me and others to write my name after a few Martinis.

Lrsa
 
lars said:
Yeah, I think every keyboard should have the letters to my name laid out in sequence from left to right in the top left corner of the keyboard. It would make it easier for me and others to write my name after a few Martinis.

Lrsa
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Fine. But what about the rest of us? Just think about poor turdlevette. He'd have to finally learn to type.
 
Trudelvetete will just have to stay sober and be our DD while he attends Hooked on Phonics during our beer and tuning sessions.

Lars
 
lars said:
Trudelvetete will just have to stay sober and be our DD while he attends Hooked on Phonics during our beer and tuning sessions.

Lars
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If you ever have the notion for a West Coast Tuning tour again,..................
 
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