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K. Wiggins
K. Wiggins, Classic Car Mechanic
Category: Classic Car
Satisfied Customers: 2957
Experience:  ASE Certified Technician, Associates Degree in Automotive Technology, 15+ years in the trade
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My flathead ford falls flat on its face when accelerating,

Customer Question

my flathead ford falls flat on its face when accelerating
JA: How old is the transmission? Have you checked the fuel filters?
Customer: yes , Im running 2 ford 94 carbs
JA: What is the model/year of your classic?
Customer: 1948 ford truck
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: different carbs new intake different distributer new coil
JA: Anything else you think the mechanic should know?
Customer: no
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Classic Car Mechanic about your situation and then connect you two.
Submitted: 1 year ago.
Category: Classic Car
Expert:  K. Wiggins replied 1 year ago.

Hello, have you checked you fuel pressure to the carbs?

Customer: replied 1 year ago.
Expert:  K. Wiggins replied 1 year ago.

Thanks, ***** ***** running power valves in both carbs? What size and what is the vacuum being produced by the engine at curising speed of 55mph?

Also are these original 94's or reproductions?

Customer: replied 1 year ago.
original carbs powervalves in both vac is 12
Expert:  K. Wiggins replied 1 year ago.

Do you happen to know the rating on the power valves you have? Also what size jets and have you measure the fuel pump volume? It should be 1 pint in 30 seconds at 500RPM

Customer: replied 1 year ago.
4.5 power valves not sure on jets
Expert:  K. Wiggins replied 1 year ago.

Thanks, there's a couple of things you can change to see if it helps. First is the accelerator pump adjustment, it's below

The throttle shaft lever will generally have 3 holes, sometimes 4.The center hole is for the standard setting. As you go towards the float bowl you get richer and leaner as you go the other way. Adjust the setting to the best condition after driving the vehicle.

Next would be to go up to a 5.5 or 6 power valve

Finally jets should be #51 for stock

Try the above and let me know how things go, we can work further if needed.

Customer: replied 1 year ago.
Expert:  K. Wiggins replied 1 year ago.

You're welcome, It's my pleasure to help!

Expert:  K. Wiggins replied 1 year ago.

Hello, I was just wanting to follow up and see how things went.