[57gary1]

Just recently my 57 Chevy has a problem going up steep hills or when the engine has a load, seems to cut in and out like its going to stall or choking out.
I did recently adjust the 2 air & gas screws on the carb. When car is idling its
fine just when I go up a steep hill I am screwed. The fuel pump is very new and the the gas lines seem ok not leaking. Help please!! Thanks Gary

 

[Pops @ Tri-5.com]

I did recently adjust the 2 air & gas screws on the carb.

Gary....By air & gas screws, I assume you mean te fuel mixture screws.....Did you use a vacuum gauge to adjust them? Have you or someone else done a tune-up recently?

 

[57gary1]

No tuneup. I just wanted adjust the fuel mixture,

I did not use a gauge just put car in drive, screwed in till it ran rough,
then backed out till it smoothed out. I did it for both screws...

Gary

 

[Pops @ Tri-5.com]

Why did you want to adjust the fuel/air mixture screws....Was the engine having problems?

 

[mickeywestsr]

Thats close to the way I've always done it. One turn after it smooths out.

 

[57gary1]

To increase gas mileage. Do you think it is a fuel mixture problem..?

Gary

 

[Pops @ Tri-5.com]

To increase gas mileage. Do you think it is a fuel mixture problem..?Gary

Could be a lot of things at this point....Is it a stock engine? How long has it been, since its had a complete tune-up?

 

[trifive]

I would check the timming, and vacumn advance.

otis

 

[57gary1]

The engine is stock and I have the Prentronix ignition no points.
Like I said it idles fine. Maybe plugs or wires but they are fairly new.
I did not have this problem till I messed with the carb....

Gary

 

[Pops @ Tri-5.com]

I've always used a vacuum gauge, when I adjusted mine.....Some will tell you that you don't need a timing light or vacuum gauge.....However, for the last 50+ years that's the way I've been successful at doing it.

See link to Shop Manual: http://chevy.oldcarmanualproject.com/shop/1955/55csm0653.html

 

[57gary1]

57 Chevy cutting in & out Fix

I decided that the fuel pump was going as it was getting worse. Driving with a strain on the engine and cutting in & out.
I replaced the fuel pump and its running fine again. This is the 3rd time replacing the fuel pump on this car.

 

[wraplock]

I decided that the fuel pump was going as it was getting worse. Driving with a strain on the engine and cutting in & out.
I replaced the fuel pump and its running fine again. This is the 3rd time replacing the fuel pump on this car.

Wow, I think I would dissect the old pump. See if it is loaded up with crud.

Don

 

[fiddlerpin]

I've always used a vacuum gauge, when I adjusted mine.....Some will tell you that you don't need a timing light or vacuum gauge.....However, for the last 50+ years that's the way I've been successful at doing it.

See link to Shop Manual: http://chevy.oldcarmanualproject.com/shop/1955/55csm0653.html

I'm with Pops on this one. Always use a vacuum gauge to adjust the idle mixture screws. Adjust till highest vacuum reached. Adjust timing with a timing light. Jim

 

[fiddlerpin]

check the tank for crud and the sending unit strainer. Most of the originals collaspe and come apart. Jim