running to rich
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New User
Joined: Oct 2001
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running to rich
I have an 1985 F250 that I'm having problems with. Just rebuilt the carb (holley 4 bbl) and now the truck is running to rich. When I lean it out, it idles to high. I have replaced the EGR valve but nothing I do seems to help. Any suggestions?
Thanks
Thanks
Senior User
Joined: Nov 2000
Posts: 285
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From: sunny san diego
running to rich
Assuming you adjusted the float levels properly, my guess would be the power valve. If you left out the gasket or didn't get it screwed in tight, this could cause your problem.
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Joined: Jan 2001
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From: Virginia
running to rich
Sounds like you are adjusting it too rich to slow the idle down. You should adjust the mixture screws for highest idle speed and vacuum. When adjusted this way, if you back the idle speed screw all the way back, and it still idles too fast, you have air coming in somewhere it shouldn't. Or maybe the choke fast idle cam is holding the idle up. I would make sure the carb base manifold is good and all the hoses are connected. After this I would suspect the secondary butterflies might be open too much. They contribute to the idle mixture and if they are open too far, the idle speed will be too high. When you rebuilt the carb, did you take the butterflies off the shaft? Or did you adjust the secondary stop screw coming out of the base of the carb? Or maybe you could just loosen the linkage and reseat the secondaries.
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Joined: Oct 2001
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running to rich
The acc pump is leaking gas, can it suck air at the same time and cause a vacuum leak? I don't know what the emission componants are, do you know where can I get a detailed map of the vacuum lines and componants. I had a fire and the vacuum lines burned so when I fixed it I thought I had it right, but maybe not. Also I replaced the gaskets under the carb and the EGR plate.
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Joined: Jan 2001
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From: Virginia
running to rich
A leaking acc pump will cause a mess and may give you a slight hesistation or bog when you step on the gas pedal. Do you have a sticker on the radiator support? This should tell you where everything goes, although I have a hard time myself figuring out all the abbreviation jibberish they use for the components. What if you pinched each line off individually and see if it slows down. Then you can decide if it is bad or hooked up wrong. I just had another thought. What if you have manifold vacuum going to the distributor advance. This would cause a high idle also. Unplug the dist vacuum line and see if the idle slows down. If it does, you need to find a ported vacuum source for this.
