possible vacuum problem
Thread Starter
|
New User
Joined: Jan 2005
Posts: 24
Likes: 0
possible vacuum problem
just dropped a 460 in my 77 highboy. runs good but when i try to climb somethin from idle it dies out. example: trying to drive up a curb. i have msd everything and it dosent have a vacuum advance, the engine is mildly built. i dont have any vacuum goin to the carb its a 770 truck avenger. just vacuum to the tranny and power booster. any suggestions?
Elder User
Joined: Dec 2004
Posts: 675
Likes: 0
From: Springfield, OR
Just a couple ideas. Put a vacuum gauge on the carb. You should see 18-20 inches at idle. Rule out any leaks in yur booster by disconnecting and plugging at the manifold then drive it and see if any better. Check any hoses or plugs for leaks. Could also be a carb or accelerator pump issue? How bigs your carb?
Thread Starter
|
New User
Joined: Jan 2005
Posts: 24
Likes: 0
i just checked the vac gauge and it is 19-19.5 consistent. the carb is a 770 cfm with a stock manual fuel pump. also i have a new booster and for some reason there is no pedal pressure and the pedal stays down when u floor it. but when engine is off you can pump it and make the pedal hard. im stumped on this one i believe its a vacuum issue but not sure.
Elder User
Joined: Dec 2004
Posts: 675
Likes: 0
From: Springfield, OR
What does the vacuum gauge do when you mess with the pedal? Ive read about this situation here before a while back. Somebody had the answer-maybe the Gashog? Sounds like the brakes are not bled or the master cylinder is not primed correctly. Did you prime the master cylinder on the bench?
Thread
Thread Starter
Forum
Replies
Last Post
mark vanford
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
5
Oct 14, 2024 12:31 AM
solo pilot
1973 - 1979 F-100 & Larger F-Series Trucks
39
Jan 16, 2014 11:16 PM
bruno2
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
11
Mar 16, 2012 08:38 AM
mh34444
6.0L Power Stroke Diesel
5
May 29, 2010 06:40 AM
