Author Topic: Holley probs  (Read 1728 times)

Offline TexasRed

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Holley probs
« on: August 24, 2008, 01:00:07 PM »
When I rev briefly the engine close to WOT, either in park (free rev) or in gear, the revs don't come down, I have to shut the engine down. Now if I'm just giving it partial throttle, it's fine. Is it perhaps the vacuum secondaries that are hanging up? I put my hand over the front barrels and got no change. I don't think I tried the back and I tried to close the throttle more by hand but that didn't seem to help. This is a 4175, so it's got small front barrels and big back ones. It kind of even almost sounds like the secondaries kicking in when I rev it. I'm not sure of the spring colour as it's whatever it had in it, it's kind of a junkyard carb. When I shut the engine down, it doesn't even run-on, so that might be the secondaries closing when there's no more vacuum. Also, it's got a 6.5 inch powervalve but it's had a 4.5 inch one too.
« Last Edit: August 24, 2008, 01:01:43 PM by TexasRed »

Offline TexasRed

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Re: Holley probs
« Reply #1 on: September 12, 2008, 05:15:40 PM »
OK, I was pretty sure I had the checkball in there when I put the secondary thing together, apparently not when I pulled it apart at a parts store. Put one in there that I think came with it. . . .not sure, could be a check ball from an edelbrock. Also, the spring in there WAS black so that's a little scary. Maybe the spring has lost tension over the years? This carb didn't come with backfire pro-tection, so it's older than a 1992. With the check ball, the secondaries don't seem to come on in park but they come on and stay on during driving when I nail it. So my question is, maybe the secondary diaphragm that came with the rebuild kit is for the wrong application? Or the black spring is old and decrepit? I'm thinking so I can get the truck back on the road, just to take an old housing and jbweld the vacuum port to keep the secondaries shut for good. Any thoughts?