RE:The problem you described about no heat and cyl. washdown. Does it act like a mid-range stumble? On my 250 L22

I have a spot in the RPM range at about 2000 to 3500 that feels "flat" and acts like a miss. The plugs look rich (black sooty and dry). The spring is missing on the heat valve on the exhaust manifold.

Once I run the truck down the highway or on warmer days (above 70*) it's fine, unless it idles too long or sets for a few minutes.

It has a Holley Rebuilt Rochester "B" on the right P/N and I was thinking it was improperly jetted. Now I'm thinking cold charge and poor atomization.

What do you guys think?


Beat to fit, paint to match