Low idle vacuum
Thread Starter
Instructor
Joined: Nov 2012
Posts: 209
Likes: 7
alright, finally got around to doing stuff, 11 deg in the garage sucks to work in finally around 30ish.
I rebuilt the holley carb, she need it pretty badly. Only thing about it didn't like is they send the kit to accommodate several different holley carbs so you end up with odd and extra pieces that make you wonder if you did everything right. Popped it on and she's holding gas perfectly.
Here's the new deal, after redoing the carb, now when i put the car in gear, she wants to stall. I can keep it running with some gas. So i start cranking up screws, turning the idle mixture screws up slightly helped, but not enough to be good. I've got the screws turned out 2 1/2 turns so far, which is further out than before the rebuild and stalling wasn't an issue. Now i read on one site is because of the larger cam that's in my motor that i may need to replace the power valve in the carb from a 6.5 to a 3.5. Make any sense?
Second thing i found in my research, puts me back to my original problem, a vacuum leak can cause the same problem. I did take some carb cleaner, despite really really not wanting to, and sprayed the intake manifold gaskets, bolts, fittings, and carb base and it basically had no affect. I even let it pool up around the gaskets, thinking maybe i'd see some bubbles pop out, nothing. really at this point i don't know what else to try, tomorrow i'll see if i can try and do a leak down test, maybe i have a valve not sealing up?
I rebuilt the holley carb, she need it pretty badly. Only thing about it didn't like is they send the kit to accommodate several different holley carbs so you end up with odd and extra pieces that make you wonder if you did everything right. Popped it on and she's holding gas perfectly.
Here's the new deal, after redoing the carb, now when i put the car in gear, she wants to stall. I can keep it running with some gas. So i start cranking up screws, turning the idle mixture screws up slightly helped, but not enough to be good. I've got the screws turned out 2 1/2 turns so far, which is further out than before the rebuild and stalling wasn't an issue. Now i read on one site is because of the larger cam that's in my motor that i may need to replace the power valve in the carb from a 6.5 to a 3.5. Make any sense?
Second thing i found in my research, puts me back to my original problem, a vacuum leak can cause the same problem. I did take some carb cleaner, despite really really not wanting to, and sprayed the intake manifold gaskets, bolts, fittings, and carb base and it basically had no affect. I even let it pool up around the gaskets, thinking maybe i'd see some bubbles pop out, nothing. really at this point i don't know what else to try, tomorrow i'll see if i can try and do a leak down test, maybe i have a valve not sealing up?
Last edited by greghennings; Mar 15, 2014 at 10:25 PM. Reason: got one of my questions answered
Melting Slicks
Joined: Dec 2009
Posts: 3,212
Likes: 639
From: Thunder Bay
Two things to check:
First make sure you used the correct metering block gasket. There will be several in your kit. If you use the wrong one (and its easy to do) you will get exactly these symptoms.
Second, once you get it running, adjust the float level with the engine running. I had exactly this problem with my last rebuild and I could hear the engine smooth out as I adjusted the float level.
Good luck.
First make sure you used the correct metering block gasket. There will be several in your kit. If you use the wrong one (and its easy to do) you will get exactly these symptoms.
Second, once you get it running, adjust the float level with the engine running. I had exactly this problem with my last rebuild and I could hear the engine smooth out as I adjusted the float level.
Good luck.
Thread Starter
Instructor
Joined: Nov 2012
Posts: 209
Likes: 7
Two things to check:
First make sure you used the correct metering block gasket. There will be several in your kit. If you use the wrong one (and its easy to do) you will get exactly these symptoms.
Second, once you get it running, adjust the float level with the engine running. I had exactly this problem with my last rebuild and I could hear the engine smooth out as I adjusted the float level.
Good luck.
First make sure you used the correct metering block gasket. There will be several in your kit. If you use the wrong one (and its easy to do) you will get exactly these symptoms.
Second, once you get it running, adjust the float level with the engine running. I had exactly this problem with my last rebuild and I could hear the engine smooth out as I adjusted the float level.
Good luck.
At the moment i can get it to idle in park, with a flashlight i can see while running both my gas levels are set to the bottom of the plug hole perfectly, i could let turn them up a little more...
