WOT shifting to 2nd car smothers itself

[Rocketman]

Left my favorite drive in burger joint today, thought I would take off good but not extra hard. Wind first gear to 4500 shift, it chokes like it is out of fuel, let off accelerator it catches and I go on. On on the highway, no issue run it up to 80 and drive it 30 miles home.

Did some searches and found advice on checking rubber hose between pump and steel lines, checking tank vents, possibly pump. I am wondering about an electric pump as I don't generate alot of vacuum now since adding the big cam and top end kit.

My carb is a Holley 3310 750 cfm. Any other ideas?

 

[Meep-Meep]

Check your rear float setting. Remove the screw plug on the side of the bowl and you should dribble gas just as you bounce the fender.

 

[HT413]

Mine had exactly your symptoms and ended up being the fuel pump pushrod.

 

[Cranky]

Mine had exactly your symptoms and ended up being the fuel pump pushrod.

What does it do in 2nd gear at 4500 nailed? The demand on fuel load is higher in the higher gears and if you're having a fuel delivery problem in first, it'll show up sooner in 2nd and even sooner in 3rd.

 

[72 Charger SE]

I had a somewhat similar problem in my old Challenger in the early 90's. I'd run out of fuel at the top end of 2nd gear (auto trans) and the car would stall for a couple of seconds. I put a fuel pressure gauge on the carb and at idle, I couldn't even read the pressure because the needle was bouncing so fast between 0 and 6 psi. Fuel pump replacement, and all was better.

 

[coloradodave]

Left my favorite drive in burger joint today, thought I would take off good but not extra hard. Wind first gear to 4500 shift, it chokes like it is out of fuel, let off accelerator it catches and I go on. On on the highway, no issue run it up to 80 and drive it 30 miles home.

Did some searches and found advice on checking rubber hose between pump and steel lines, checking tank vents, possibly pump. I am wondering about an electric pump as I don't generate alot of vacuum now since adding the big cam and top end kit.

My carb is a Holley 3310 750 cfm. Any other ideas?

The mechanical fuel pump is not dependent on vacuum to work. All above are good suggestions to check. A temporary fuel pressure gauge, plumbed into the fuel line between your pump and carburetor and strapped to the cowl will tell you a lot. Watch it under acceleration and see if the pump is providing 5-7 lbs. through the RPM range you use. Make sure your fuel filter is clean also.

 

[Rocketman]

Check your rear float setting. Remove the screw plug on the side of the bowl and you should dribble gas just as you bounce the fender.

Thanks for the tip, this was the problem, that damn float was screwed all the way down, I wonder it someone screwed with it at a car show or cruise in. put in a new gasket, new screw and seat, runs like a top again.

 

[coloradodave]

Good call, Meep...

 

[Cranky]

Thanks for the tip, this was the problem, that damn float was screwed all the way down, I wonder it someone screwed with it at a car show or cruise in. put in a new gasket, new screw and seat, runs like a top again.

Keep an eye on it....I've seen floats develop a leak and slowly sink. I like to set mine to just where they barely dribble without moving the car however, that's easy to do if you have an electric fuel pump but if the car idles smoothly, you can still do it that way. Check it in a week or so to make sure the level stays the same no matter where it's set.