69 E-Type sputters when making left hand turn

[DonJ]

I have a 1969 E-Type roadster. The last time we took it out for a ride I noticed on the way home that on 3 occasions when making a left hand turn the engine would stutter momentarily, only a second or two, while making a left hand turn. I took it into my mechanic for some other issues and mentioned this to him. I got a phone call from him today and he said they took it out for a ride and yes, the same thing happened to them. He mentioned that is seemed more pronounced with up-hill lefts. I am wondering if it could be the first signs of a fuel pump going bad, but I have no idea why left hand turns. The mechanic will check fuel pump pressure but I am wondering if anyone has any ideas or has ever heard of such a thing.

Thanks,
dj

 

[Marvin Gruber]

Not that uncommon. Sounds like fuel floats in carbs, floats could be filling up with gas and the left turn moves floats more than right turn.
Marv

 

[DonJ]

Marv, thanks for the response. Can I lean on you a bit more? Can you expound a little on you theory. I would like to get a better understanding of what you think may be going on.

Thanks,
dk

 

[Geo Hahn]

I had this exact same problem -- engine would sputter on fast lefts.

The fuel floats were leaky and partially water-logged (okay, fuel-logged). The causes the float to sit lower and thus offer too much fuel.

They weren't so loaded with fuel that they would fail to shut the valve... until the hard left. The left turn pushed fuel to the outboard side of the bowl which caused the float to sit even lower than usual -- with the result that the valve did not close and lots of fuel was sucked in the intake.

It felt like the engine was starved for fuel but in fact it was flooded. Once I was out of the turn it would cough and clear and things would be okay again.

The simple solution was to replace the floats with a pair made from Nitrophyl - those are solid and should never take on fuel. I replaced mine in situ rather than remove the carbs just for this.

Having the carbs upside down on the bench is the 'by the book' method but if you are careful you can set the float height with the carbs still in place.

At the same time I replaced the screws that secure the float bowls with socket-head cap screws as those are easier to undo and do than the flat-head screwdriver screws that are stock. A small thing but helpful.

Some additional, possibly useful, material here: https://forums.jag-lovers.org/tv.ph...lW5pAaVMwbWwIkTc2gug3MTaF0mZQ2hxCmxlYAQDDZh7Q

 

[DonJ]

So I talked to the shop today. They said they were going to check the float levels. I gently suggested they closely inspect the floats (based on the responses I received here). Couple of hours go by and I get a call back. It seems that they changed out the floats and the stuttering has disappeared. You guys nailed it. Special thanks to Geo Hahn. You also helped me with tires several weeks ago.

dj

 

[Marvin Gruber]

Don,
glad you found it, Geo gave a much better explanation than I could have done.
Marv

 

[LarryK]

It is best when doing any British car carb, to use anything you can get that is alcohol resistant. The modern fuels eat up all the old rubber and brass and corrodes copper equally. If they sit for any amount of time use the marine grade stabilizer as it saves boats aluminum tanks and should do well on our steel and brass components.