Engine Hesitation When Hot

[CJWAZZ]

Hi,

A year or so ago I installed a Holley street dominator intake manifold and Holley truck avenger 470 carburetor on my

 

[BroncoJoe19]

I can't walk you through how to adjust a carb, but we had an issue here not too long ago where the fuel pressure was a little high and the Holley tech suggested adjusting the float level. I'm not sure how that worked out, my suggestion was to get a fuel pressure regulator.

So if the problem has been since you made the change, I would check the fuel pressure and then talk to someone about checking the float level, then adjusting the carb fuel mixture needle valves.

Now you'll have to wait for someone who has more recently worked on carbed engines to give you some advice that you can actually put to good use. /emoticons/[email protected] 2x" width="20" height="20" />

 

[CJWAZZ]

Thanks for the response. After posting yesterday I found another post on here outlining a similar problem. To deal with the idle problem I drove it around until it was hot and choke plate opened and adjusted the idle mixture screws which made a huge difference. Turns out that I had to richen each ***** by about a half turn, I guess that makes sense in that it idled fine when the plates were closed (less air) and badly with the plates open. This did not help with the hesitation problem so I messed with the timing and found that advancing it by about 8-10 degrees from where it was at before made a huge difference, it's running much much better now at idle and under power when hot and cold.

The only thing I'm still a bit confused about is why it previously had plenty of power when cold but no power when hot. I always assumed that if the timing was off, it would have the same power problems at all temperatures. Anyway, it's much better now so I'm happy. /emoticons/[email protected] 2x" width="20" height="20" />

 

[Leadsled]

Thanks for the response. After posting yesterday I found another post on here outlining a similar problem. To deal with the idle problem I drove it around until it was hot and choke plate opened and adjusted the idle mixture screws which made a huge difference. Turns out that I had to richen each ***** by about a half turn, I guess that makes sense in that it idled fine when the plates were closed (less air) and badly with the plates open. This did not help with the hesitation problem so I messed with the timing and found that advancing it by about 8-10 degrees from where it was at before made a huge difference, it's running much much better now at idle and under power when hot and cold.
The only thing I'm still a bit confused about is why it previously had plenty of power when cold but no power when hot. I always assumed that if the timing was off, it would have the same power problems at all temperatures. Anyway, it's much better now so I'm happy. /emoticons/[email protected] 2x" width="20" height="20" />

Sounds like you were starving your engine and the fuel was detonating probably when the piston was on the way down or when it was at TDC instead of on the way up like you have it now.