Removed Altitude compensator .
Just thought I would post this. But I rebuilt my motorcraft 2150 last weekend on my 1979 j-10 360. It had the Altitude compensator, it was running smooth but was not very responsive and it felt weak, plus I just bought it and the carb was dirty. Well I did not like that "growth" on my carb to begain with, I would have looked around for another, but someday I plan on at least a new 500 Holley, maybe more, but for now a rebuild at the least. So I tore it apart and it looked like to me that one, (only one), of the two ports that the compensator feeds air into was very discolored and looked like it was leaking air. I live on the Gulf coast, so the Altitude compensator is not a concern to me very much. So I looked around and found that 3/8 pipe plugs would screw into the ports with a pretty good bite. The ports also look to taiper in twords the venture so there was no chance of the plug somehow going all the way thru. So I put some good permatex on the plugs and screwed them in untill the plugs were almost flush, and were feeling very tight. They were nowhere close to pertruding into the venture. I took the little compensator choke flap and rod off, rebuilt the rest of the carb, which I found a blown power valve and a very sick accelerator diaphram. Now The carb looks much better and runs much better. Much more response. Of course since I found other problems I cannot say how much of the increase was due to this removal. Im sure if its working and you live on the coast at low sea level you would not feel no improvement. If it was leaking than I was probably running lean and that would have contributed to the low power feel. But the carb for sure looks better.
The power valve was likely the power problem. Vacuum likes crack and not hooked up right will do that too. Did you advance the timing? That will perk it up a lot too.
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I know the carb had problems and thats where I was getting most of my power loss problems. I can fell an engine with a power valve problem the minute I drive it. But I could tell the compansator was leaking air into the venture. The seal in the piston assembly did not look good even. This would cause additional (at sea level) uneeded air leaning out my mixiture and causing a softer power band. Itss gone now and good ridence. Im running this motorcraft only untill after the new year when I will put a 500 Holley.My intial timing is at 10 degrees, my centrifical advance system on my current dist. does not feel the best, but and I soon will be putting a quality HEI on it, like today, i already have it and the wires on the desk by my laptop here, I then will be doing more tunning on my total advance curve. But its running much better now and soon will be much better even. Thanks
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