PDA

View Full Version : Carb question


pga4653
10-29-2008, 12:38 AM
Hey everyone. I am new to posting, but have enjoyed reading many of your posts. I have a mint 1990 Tristar with the 351. I have had some problems with a flat spot when accelerating slowly to plane. I have tried every possible adjustment on my Holley that I can come up with. The only thing that I have not tried is a rebuild, new carb, or adjusting the float. Any thoughts or suggestions for tuning or recomendations for replacement.

I live in Atlanta and can't find anyone to work on it for me.

I look forward to your thoughts.

Skipper
10-29-2008, 10:23 AM
From the SKIDIM FAQ section:

HOLLEY CARB ADJUSTMENT INSTRUCTIONS
1. Rev up the engine to clear it out.
2. Turn air screw in until you hear engine begin to bog and miss.
3. Now, turn screw out with 1/2 increments until you hear that the engine is steady and running smoothly.
4. Repeat procedure on air screw on opposite side of the metering block.
Thatís it!

This is how I have always adjusted the carb.

TRBenj
10-29-2008, 12:08 PM
Skip, the idle adjustment wont help him much- the flat spot isnt occuring in the idle circuit.

Can you describe the symptoms a bit better? By your description, it sounds like you dont have any hesitation if you go WOT from idle- is that correct? That would seem very strange.

Before adjusting anything on the carb, you need to have your timing set properly, by the way. Have you done that?

88 PS190
10-29-2008, 12:46 PM
Always a good bet to inspect the ignition before getting too friendly with carbs.