Holley Vacuum Secondary

[Tx Surveyor]

Hey Everyone,

I've got a 305 with a Holley on top of it, not sure of the make or model because it was on there when I purchased the truck. Anyone tell me how to tell?
I'm having problems with the truck, when I try to accelerate hard the engine just bogs out, cuts in and out and won't down shift. It also shifts late in all the gears, it will rev up high and then shift real hard. It doesn't do the shifting problem all of the time, but 90% of the time.
My mechanic tells me this is a vacuum secondary problem with the Holley carburetor. He also says all Holley carbs are junk and I should just replace the entire carb instead of the headache of the vacuum secondary.
Any opinions on this? Should I just replace with an Edelbrock? How hard is it for me to replace the secondary myself?

Thanks,
Surveyor

 

[scooter122983]

Do the secondary change, its not hard to do. Make sure you are using the correct spring tension for the vac secondarys also. The shifting problem is most likely a disconnected vac line or mis adjusted kickdown cable. That problem is not related to the carb. You may want to look into a complete rebuild kit for your carb, for that you will need the part no. this is located on the choke tower on the front of the carb. I also find that there is alot of uneducated hatred towards the holley carbs. Personally I find them easier to work than Edelbrock and most parts are interchangeable. I got a book called "Super Tuning and Modifying Holley Carburetors" this book explaines anything that you would ever want to do to your holley carb. Dont throw away your holley because someone told you to. Learn as much as you can about it and make it work for what you want.

 

[rcamacho]

Ditto on that advice. I'd start with the shifting adjustment first as that can cause your tranny to burn up if not taken care of.

As to the holley, pull the list number off the airhorn and look it up on www.holley.com. The quick change vac cover and spring kit should be more than enough to get the bog under control.

 

[Tx Surveyor]

Thanks for the advice fellas. I'll definately look into it.

How do I adjust the shifting point?

 

[Chevy305]

Does the Holley have 2 fuel feeds or just one?

 

[Tx Surveyor]

Does the Holley have 2 fuel feeds or just one?

I'm 90% positive it only has 1 fuel feeds. I can't check right now, it's covered in paper and tape for paint.



Surveyor

 

[Chevy305]

I'm 90% positive it only has 1 fuel feeds. I can't check right now, it's covered in paper and tape for paint.



Surveyor

Ok sounds like it could be a 4160 which is a great foundation for a DD or offroader. Tuned correctly, that carb will be the last carb you will ever need to have.

 

[Tx Surveyor]

It may be a bad to the bone carb but right now it's being a pain in the ass.
Any good sites to look into on how to tune this thing myself? On how to fix the vacuum secondary?
How about fixing my shifting problem?


Thanks

 

[rcamacho]

Best way is to pick up a holley tuning book. Chiltons or other manual should go over how to adjust the transmission linkage/TV cable. Once you have that squared away you can mod the carb for much better off road performance with some baffles, extended vents and spring loaded needles.

http://classicbroncos.com/carb_tricks.shtml

 

[scooter122983]

It may be a bad to the bone carb but right now it's being a pain in the ass.
Any good sites to look into on how to tune this thing myself? On how to fix the vacuum secondary?
How about fixing my shifting problem?


Thanks

Read my first post pertaining to tuning the carb. As for the carb being a 4160 that is a good foundation I personally would convert it to a 4150 by replacing the secondary metering plate with a metering block. This is going to make tuning easier by having the extra jets to be able to change. Also look into offroad mods as they will make your life easier.