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Carb question, Update 10/13
https://www.slantsix.org/forum/viewtopic.php?t=49551		 Page 2 of 3
Author:  73dust225 [ Wed Aug 15, 2012 12:08 pm ]
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Well looks like I've got some reading to do I guess I better stock up on the aspirin.
Author:  73dust225 [ Sat Aug 18, 2012 11:50 am ]
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Well I just checked the vac. and it was around 10 lbs. I then started spraying brake cleaner around the carb and found that it needs a throttle shaft bushing. I guess I didn't spray in the right spot before.

So now I need a new carb or if someone could recommend a good rebuilder in SoCal IE area that could let me know if it's rebuildable I would appreciate it.

Thanks for everybodys help.
Author:  SlantSixDan [ Sat Aug 18, 2012 12:27 pm ]
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Quote:
Well I just checked the vac. and it was around 10 lbs
Vacuum is measured in inches of mercury (or just "inches"), not in pounds.
Quote:
I then started spraying brake cleaner around the carb
Very, very very dangerous. Never do this. It is an excellent way to poison yourself if the wind shifts and blows exhaust towards you. Chlorinated brake cleaner + flame = phosgene, otherwise known as nerve gas. Use carburetor cleaner for a test like this.
Quote:
So now I need a new carb
Get one of these.


Got those books on the way yet…?
Author:  73dust225 [ Sat Aug 18, 2012 1:01 pm ]
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I have a factory service manual for my year I need to order the others. I was looking at that carb earlier but the throttle linkage looks different. My mistake I'm used to lbs.
Author:  SlantSixDan [ Sat Aug 18, 2012 3:00 pm ]
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Quote:
I have a factory service manual for my year I need to order the others
Yes -- get them soon.
Quote:
I was looking at that carb earlier but the throttle linkage looks different.
It is a direct drop-on replacement for any original Super-6 carb.
Author:  Rug_Trucker [ Sat Aug 18, 2012 7:36 pm ]
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Even with a really sloppy shaft you should be able to get a higher reading than 10. Time to play with the mixture screws, idle screw,timing etc.

Got a tach?
Author:  SlantSixDan [ Sat Aug 18, 2012 8:13 pm ]
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...check for timing chain slack...
Author:  73dust225 [ Mon Aug 27, 2012 8:45 am ]
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Well as usual I jumped the gun and it's not the carb but at least I have a nice new carb. After I installed the carb and got it running it was basically the same so I checked and remembered the vac and it is at 12 in. up and down.

As for the timing chain I know it's possible but at 61000 miles on the car I don't think thats the problem. Before I had changed to the SS set up the car ran ok. So I guess I'm going to have to start from the beginning and take it apart inspect and put it back together.
Author:  SlantSixDan [ Mon Aug 27, 2012 9:03 am ]
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Quote:
I checked and remembered the vac and it is at 12 in. up and down.
You've got me wondering if your EGR system is creating an exhaust leak into the intake tract -- either due to a leaky EGR valve or one that's not hooked up correctly. What can you tell us about your EGR system's presence and hookup?
Quote:
As for the timing chain I know it's possible but at 61000 miles on the car I don't think thats the problem
Don't be so sure. I've seen slant-6s with lower miles than that and slack timing chains. They weren't putting very durable T-chains and sprockets in during those years. It's easy enough to check without disassembly. See here
Author:  73dust225 [ Mon Aug 27, 2012 12:39 pm ]
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The EGR has been removed and replaced with a solid gasket and steel cover plate. I did remove and check these to see if it was leaking to find it was not.

I will check the timing chain before I start taking apart the intake.

Dan can you suggest what gaskets to get for the intake when I take it apart. I would like to buy a good quality one instead of Autozone one.

Thanks, Richard
Author:  SlantSixDan [ Mon Aug 27, 2012 12:51 pm ]
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Quote:
The EGR has been removed and replaced with a solid gasket and steel cover plate. I did remove and check these to see if it was leaking to find it was not.
Reinstalled cover plate with new gasket?

Intake manifold: iron or aluminum?


It is very much worth your while to get the good gaskets for the manifolds-to-head and intake-to-exhaust junctions.
Author:  73dust225 [ Mon Aug 27, 2012 2:15 pm ]
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New gasket yes. Iron manifold
Author:  73dust225 [ Sun Sep 16, 2012 7:53 pm ]
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Well I'm at the end of my capability. I ordered the gasket set you suggested Dan ( nice quality set) and then took apart cleaned and replaced the gasket and parts and NOTHING HAS CHANGED :evil: . Just for something to check I checked the compression and all cyl are fine.

I've always been the type of guy who can remove and replace parts ie brakes, suspension, intake swap but when it comes to solving a problem like this I'm lost. Right now my biggest problem is money I just can't afford to be taking apart and putting back togeather the various engine parts. the only thing I can think of is maybe there's a crack in the intake I can't see or trace. What else could give you weak vacum? The car runs fine when driving around but when at a stop it barely wants to run. What to do I just don't know :shrug:
Author:  Aggressive Ted [ Sun Sep 16, 2012 9:25 pm ]
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Out of curiosity, where does the vacuum line go coming off the number 6 runner fitting? What ever it is plugged into maybe causing a vacuum leak. Even a ruptured vacuum diaphragm in the distributor, air cleaner hot air door actuator, the sensor or choke pull off can cause it to run like your describing. Try plugging that line and see how it runs.

As a reference......
I am running a completely stock 79 SL6 that is in horrible tune because of broken manifold bolts and the stock steel shim gasket is leaking. In fact when it starts hot it will blow blue smoke out between the manifolds and head. As bad as it is, it will still pull 18" of vacuum at 750 rpm and 16" at 600 rpm in gear and mileage fluctuates between 22.8 and 23.8. It will idle for hours in traffic at these readings.....It is getting worse mileage as the leaks progress. In June it was getting 25 mpg. In a week or so the manifolds are coming off and it will be getting all new gaskets.

Don't give up, it must be something simple....
Author:  73dust225 [ Mon Sep 17, 2012 8:53 am ]
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At one time I capped every vac. source on the carb and on the intake and this made no difference on the guage. I've just run out of ideas as to what to look for or at. Right now I'm almost ready to put the 1bbl and intake back on to see if it changes anything. the problem with that it's just more gaskets I got to buy. Sometimes I just stand there looking at the engine wondering what went wrong. I know it could be something simple but I guess my simple mind just ain't getting it lol.
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