tuning a carter afb for e85

Reply Subscribe

Thread Tools

Search this Thread

Oct 18, 2005 | 06:04 PM

clutch

Thread Starter

Freshman User

Joined: Oct 2003

Posts: 25

Likes: 0

tuning a carter afb for e85

I recently decided to run my truck on e85 (85% ethanol) it is a 351w with 8.5:1 comp. and a 4bbl carter afb. I took the fill up the tank and see what happens approach to this conversion, and despite a few tense moments on the first trip I've about got it dialed in. I put larger jets in the secondaries and smaller metering rods in the primaries (they were a little rich to start with). I set the acceleration pump up and put in a larger fuel filter. It runs fine at higher rpms and accelerates as good as before. The only trouble i've been having is coming off idle. when I pull away from a stop it hesitates, sputters, and some times dies, as soon as I give it a little more throttle it evens out. What should I look at now.

Oct 18, 2005 | 07:52 PM

Ford_Six

Hotshot

Joined: Oct 2002

Posts: 18,488

Likes: 22

From: The Big, Oregon

Quote:

Originally Posted by clutch

What should I look at now.

Any rubber part in the system. All the hoses and the fuel pump need to be rated for alcohol/e85, as well as the seals in the carb.
It may need a larger accelerator pump shot or you may need to advance your timing a bit.

Oct 18, 2005 | 07:56 PM

1081

Elder User

Joined: Mar 2004

Posts: 856

Likes: 0

From: Kansas City, Missouri

Accelerator pump in the carb?

Oct 19, 2005 | 06:55 PM

clutch

Thread Starter

Freshman User

Joined: Oct 2003

Posts: 25

Likes: 0

I advanced the timing and that seemed to help. It now runs about as well as it did before. All of the rubber gas lines were replaced recently and I check them often. Milage is about the same, so unless cold weather gives me a lot of trouble I'll probably stick with it.