Skip the auto shop - Our mechanics make house calls

Q: WHEN I ACCELERTE FROM A STOP ITS FINE IT LEAVES BUT ONCE IM GOING 45 MPH IT BOGGS DOWN AND WONT ACCELARATE

asked by on

I have an old classic pick up 1952 International. L110. It has a 350 Pontiac engine 4.9 with a carter 4bbl carb. I drive only for local cruises. I can accelerate fine but once I have going approx 45-50 mPH I try to step on gas to keep momentum and engine boggs down. I can then also slam on gas to open all 4bbl and same thing. only RPM sound higher but the vehicle wont move. I have tried moving the fuel mixture screws and it helps a little but I still dont get all the HP that the engine can do. any ideas?
My car has an automatic transmission.

Hi there. What you are describing is very common with either a vacuum leak, or an issue with the jetting in the carburetor. Most of the time, a bogging issue is caused by too much fuel (or a rich situation). This is typically controlled by the main jets in the carburetor. It is also possible that you have a dirty fuel filter or a fuel pump that is not working as well as it should be. Check these components to see if it clears up. If not, you might want to have a performance shop or professional mobile mechanic come to your location to try and diagnose and resolve this problem.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  • Home
  • Questions
  • WHEN I ACCELERTE FROM A STOP ITS FINE IT LEAVES BUT ONCE IM GOING 45 MPH IT BOGGS DOWN AND WONT ACCELARATE

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Serpentine belt keeps coming off

The pulleys will not just lose their alignment. For this to happen, there has been a failure somewhere. One of the most common causes I have found for this problem, on a serpentine belt system, is that the belt tensioner...

Q: Brakes won't stay pumped and fluid overs the area where u fill it up at

If you are bleeding the brakes out and keep getting air in the system then you test system and it still feels like it has a low pedal again. The brakes are bled again and gets air in it again...

Q: The car idles rough and is shooting out codes p0017, p0016.

Hi, from what you’ve described and the nature of the two codes, it sounds like a timing problem. It’s possible that the timing chain has stretched, the timing chain tensioner needs to be replaced, a timing chain guide has slipped...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...