Poor fuel mileage
Thread Starter
|
Laughing Gas
Joined: Jan 2014
Posts: 1,077
Likes: 500
From: Kenai
Poor fuel mileage
My 78 bronco is getting about 7mpg with the 400 /C6 in it. I know it won't get alot better, but it would be nice to be in the 9mpg range. It has an edelbrock 1405 with manual choke that opens fully, MSD aftermarket ignition and distributor, with no vacuum advance.
The exhaust smells really rich. I ordered some new jets and metering rods to try to lean it out.
I measured the base timing, it is about 10-12. But full mechanical advance is less than 30. I bought a MSD mechanical advance adjustment kit, I wil try a different bushing first.
What else can I try to improve this a little? It does runs and starts really well.
The exhaust smells really rich. I ordered some new jets and metering rods to try to lean it out.
I measured the base timing, it is about 10-12. But full mechanical advance is less than 30. I bought a MSD mechanical advance adjustment kit, I wil try a different bushing first.
What else can I try to improve this a little? It does runs and starts really well.
More Turbo
Joined: Jun 2020
Posts: 648
Likes: 394
From: Montana
You can use vacuum advance... The difference on mine between no vacuum advance and vacuum advance is about the 2 mpg you would like to improve. You should check to make sure your mechanical advance is working correctly too. When mine had a gummy mechanical advance, and a blown vacuum advance canister I got a bit over 5 and with everything working correctly I can brush just above 9 on a good day.
Thread
Thread Starter
Forum
Replies
Last Post
BrittsNFords
1967 - 1972 F-100 & Larger F-Series Trucks
23
May 22, 2016 06:50 PM
mabigredtruck
1973 - 1979 F-100 & Larger F-Series Trucks
2
Jan 25, 2010 01:16 PM
PHetrick
335 Series- 5.8/351M, 6.6/400, 351 Cleveland
24
Apr 19, 2007 01:05 PM
Dr. Beeker
FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)
4
Mar 26, 2003 07:11 PM
BigF250
Big Block V8 - 385 Series (6.1/370, 7.0/429, 7.5/460)
13
Nov 30, 2002 06:13 PM
