Carb adjustment ?

[RustyRed]

I drove the Mustang today.

I've noticed of late that sometimes when I am going around a corner and let off the pedal the car sort of stumbles like it's running out of fuel.

The car was running fine not long ago and I have done nothing to it except drive it so I haven't changed anything setting wise.

Any ideas of places to start looking to chase this down or ideas as to what might be the issue?

One thing I could think of is I took it to a cruise in a couple weeks ago and seems like the problem started right after that (think on the way home). I am wondering if some jerk messed with my carb adjustments. Probably not likely but it could happen I suppose.

I also filled up on the way to that cruise in so I guess in theory it could also be something in the gas but otherwise I can't think of anything that would have changed to make it go from running fine to the current issue.

 

[B67FSTB]

Don't look too far , I guess you first want to change the fuel in the gastank. IMHO

 

[RustyRed]

Don't look too far , I guess you first want to change the fuel in the gastank. IMHO

I wasn't going to do much to it to be honest till I burned this gas up and added a new fill up since the issue started after the last fill up. Just can't think of anything else that could have changed.

Duane however wrote me to say I should rebuild the carb :confu

 

[Horseplay]

It runs fine under all other circumstances except when letting off the pedal through a corner?

 

[RustyRed]

It runs fine under all other circumstances except when letting off the pedal through a corner?

Yep.

Gets crap for gas mileage, enough so that I've been wondering if it isn't running a little on the rich side. But seems to run fine other than corners where you let off the pedal. Of course with a 302 (30 over) mild cam, Holley 600, 3.55 gears in the rear and ported GT 40's I didn't exactly build it with fuel efficiency in mind. Tranny is a C4 with shift kit, higher stall, blah, blah, blah but with the gearing it runs about 2,500 rpms at 50 give / take mph which I am sure does nothing for fuel economy.

 

[Horseplay]

So if driving in a straight line you don't suffer the same when you get off the gas, right? If that is the case, I would be looking at float level, I think. The only thing I can get from your description that occurs only in a corner would be the forces that would push your fuel to one side or another. Coupled with the drop in RPMs when you let off the gas I can see you sloshing gas around and causing problems.

 

[RustyRed]

So if driving in a straight line you don't suffer the same when you get off the gas, right? If that is the case, I would be looking at float level, I think. The only thing I can get from your description that occurs only in a corner would be the forces that would push your fuel to one side or another. Coupled with the drop in RPMs when you let off the gas I can see you sloshing gas around and causing problems.

I haven't noticed it going in a straight line but I'll get back to you after the drive home this evening....

 

[AzPete]

Try staying on the gas thru a corner and see if it wants to die. If it does it both coasting and under power, it very well could be the float level. It also could be to high and gas slushing over into the intake.......any black smoke when accelerating from the corner?

 

[Mach1Rider]

If the level is any higher than the very bottom of the sight hole, it is most likely your problem.
Another thing to check is the airbleed holes for plugged or gummed over from sitting.
A quick carb cleaner spray over them will clean them and make it run better.

 

[RustyRed]

Try staying on the gas thru a corner and see if it wants to die. If it does it both coasting and under power, it very well could be the float level. It also could be to high and gas slushing over into the intake.......any black smoke when accelerating from the corner?

That I can answer. If I stay on the gas even slightly then it doesn't try to die out on me.

Haven't noticed any black smoke but that doesn't mean there isn't any.

 

[RustyRed]

Just to follow up on this one.

I drove home Friday afternoon but there was no traffic and it ran fine the whole way. No issues with corners or anywhere.

The problem seems to come up when I idle it alot.

On the way to work on Friday I got stuck for a few minutes because they are working on the street by my office and someone had parked a beer delivery truck in front of one of the local watering holes. It was right after I had been stuck in traffic a few minutes at idle that it started acting like it wanted to die out going around corners getting into the garage at work.