Power valve

[steve340]

When you say Promax base plates - do you mean metering blocks??

 

[Bird 426]

I actually have both on the end carbs. Also, I have the floats with relief in them so that they will not interfere with the Promax main jet plates that have replaced the stock metering plates. I have tried metering plates and the same condition exists. The stock end metering plates are stamped #41. Drill size on the plates are driver's side #44 and passenger side #49.

 

[Demonic]

Is it rich all the time or only after it warms up? I had a factory Holley that would go warm after 20 minutes. It was the gasket between the body and baseplate. Milling the main body at the gasket surface cured it.

 

[Bird 426]

I would say after it warms up. Takes a lot of choke to keep it running at a lower rpm. My intake base on the rear carb is slightly warped, this winter I plan on pulling the intake and have a friend make a cut across all three. Will see if I can find a warp in the carb bodies. I have sprayed ether around the carbs and did not get an rpm rise.

 

[steve340]

Those parts pictured are secondary metering plates. Did you refit the thin metal plates and thin gaskets to the carbs?
They are required to support/seal the metering plates were the body of the carb is relieved out for a power valve.
That could cause it to run rich.

 

[Bird 426]

Yes I did. You can see them in the picture.

 

[steve340]

They would also be required with the Promax jet plates that was what I was meaning.

 

[Bird 426]

I do not have them installed with the Promax plates. Seems like I tried that and it didn't work for some reason. I did not like the Promax plates up against the gasket. So, how is it done, I am missing something. If there were instructions with the plates, I do not have them. The Promax plates were in there when I bought the car.

 

[steve340]

I have never used what you have.
The thin plate and grey gasket should fit any carb - can't see any potential issue.
They would also need the 4160 secondary style gasket.

I have fitted a few Quickfuel ones but never got instructions.

 

[Bird 426]

Okay. It's been 2 or 3 years ago since I tried putting that plate in. I do not remember why I didn't think that it would work. Will have to look at that again. Did look back into threads concerning the Promax installation. They do not mention using that steel plate behind the Promax plate. But I will look into it.

 

[steve340]

I did a little searching on the internet and a business called Chicago Carburettor has posted exploded view drawing of the original Holley outer carb showing the gasket and support plate.
IMO the Promax jet plate would also need the support plate and gasket.
It may have nothing to do with your problem or everything. Hard to know.

 

[Bird 426]

Going to try and work on it tomorrow.
Thank you

 

[451Mopar]

If it work OK before, take a small wire and clean out the air bleeds

 

[Bird 426]

I took the center carb off yesterday and blew air through all passages, all seemed to be good. Went down 2 more jet sizes on same, checked T-slot, took fuel filter off and installed a fuel pressure for testing fuel pressure again, new spark plugs. Going into town today, 2 barrel drive only, about 35 miles round trip. Will see how things look when I get home. I can run a wire down the airbleeds too.

 

[Bird 426]

Took the fuel pressure up to 6psi. Plugs look like this, all 8. I left the 4.5 pv in. At 2-2500 rpm the AFR's were 13.5-14 ish. I always felt like it was going lean when the jetting got down in the 66/65 area, I was wrong, it likes the 63's. After a 40 mile trip at 55 mph, and a little in town driving. I live out in the country. Think I am there for the 2-barrel. Now on to the bog.