I have a 1970 442 Automatic. I changed the fuel pump because it was leaking oil from the base. It started right up. But after a few minutes it started to run rough. It would not idle. It was running very rich & wanted to stall. Very strong smell of gas. OK maybe there is dirt in the seat. So I rebuilt it. When I took it apart, I noticed gray junk in the inlet. When I was putting it back together, I noticed that the brass float was rubbing on the body. Now how could that be? I tapped on the float sides to make it clear. I've rebuilt this carb at least twice before & never seen this. I noticed the inside of the bowl was rough like the inlet bore. My question is: could the gas with alcohol be eating the inside of the carb? It does sit sometimes for weeks without being run. Could it be the Staybil I use over the winter? I put it together & it works


very well. Has anyone seen this with a Quadrajet?

 

Yes, I have seen damage like that in other carbs.

 

What can be done about it? Can it be coated with something?

 

You are seeing the effects of using ethanol base gas. It will totally destroy your carburetor over time. If you can rebuild it again shop for ethanol FREE PREMIUM GAS if you want it to live. I have the sending unit from the Syclone if you want to see the long term results of ethanol gas at only 10%. I can post a picture if you like.

 

Yep, happened to my carb a while back, not sure there is any remedy aside from getting a new core/body....

 

This is the original sending unit from my Syclone. You are seeing the effects of 10% ethanol premium gas. What I can't show you is the fuel pump. Itt was a stainless steel body 255 pump. What was interesting is, all stainless steel has impurities and the ethanol gas ate though the body of the pump and we all know what happened with that.

 

Wow. That's horrible. I have other Quadrajets that I can probably switch the center core with. I never expected this. Do you think coating the inside with something could help? I live in Long Island NY & have never seen ethanol free gas here. I've read articles about them wanting to raise the content to 15%. I guess it's something else I'll have to keep an eye on. Thanks for everyone help with this new to me problem.

 

Look at pure-gas.org for stations near you. There is nothing listed in Long Island, but there may be somewhere close.

My son does some small engine work, mostly for family, friends, and neighbors. Most of his projects are replacing parts damaged by ethanol gas.

 

I have a 1929 Model A Ford and put some ethanol gas in the tank. Within a week it had ruined the glass sediment bowl gasket so bad it leaked the tank dry. Fortunately I had only put three gallons in the tank. Replaced the gasket with good old fashioned cork gasket and have not had any other problems. Lucky, the carb is cast iron so nothing was hurt there.

 

Not only is ethanol base gas bad for carburetors, it even worse on gasoline hose as it will turn the inside of the hose to a gel like mush. Which part of it will separate and plugged other components, basically making the parts junk unless you spend alot of hours cleaning each orifice individually. Now you can get around the fuel hose problem or pro-long it by using fuel injection hose, however you cannot get around the carburetor and or fuel pump/regulator corrosion issue.

As stated above find a ethanol free gas station but be aware that the ethanol free gas can vary from 89 to 100 octane. Some places will call it recreational gas. Do your research as your car depends on it. In my area it's called recreational gas and is only 90 octane, so I have to add octane additive. I recently found a local airport and a boat filling sites that has a much higher octane rating that will need looking into. I'm sure that will be some kind of restrictions but need to check.

 

Supposedly Stabil 360 will protect your fuel system from ethanol. We'll see. This his getting to be a hard hobby to have. Thanks again for all the help.

 

Not the evil ethanol boogeyman again! Y'all are a trip.

Seafoam is better than Stabil. Change my mind.

 

Interesting topic on the harmful affects of ethanol.

I am curious what our community has to say about the effectiveness of additives and which one is preferred.

 

I don't know which is better. That's why I'm here asking. I always thought the damage was only to seals & hoses.
After seeing the inside of my carb. I'm finding out different. I bought a Lucas ethanol product. Part of the problem is that it takes a while to find out what works.
If fleming442 thinks Seafoam is better than I respect someone who has used that product. Maybe I'll try Seafoam. Thanks all of you.

 

I know this is an old post but I wanted to add that I think the brand of fuel makes a huge difference. We have had Ethanol in our fuel here in the Washington DC area for at least 30 years now and to be honest with you I have not had much of an issue with it BUT ....... I have used Shell gas for almost that entire time. My Wife's Riviera and my S-10 both have carburetors and the only issue I have seen on them is the fuel tends to evaporate when you park them and if its more than a few days it takes an extra few minutes cranking to get fuel back in the carb.

The Riviera is going on close to 200K miles and when I did the engine a few years back I went through the Quadrajet and it was very clean inside.

Same goes with all of my lawn equipment. The only thing I have had an issue with was the snow blower after it sat unused for almost 3 years. I really cant blame that on the type of fuel.

 

I think that has more to do with the inlet thread damage and repair than it does with fuel type.

 

Did you see the grey corrosion crude ? Not sure how the threads have anything to do with that ?

 

Same experience here in Phoenix. 24 years and no issues with the Cutlass or any of the lawn equipment.

 

If you look closely at the picture, the corrosion is all behind the threads. Also, this carb inlet was Heili coiled 15 years ago. I cut open the filter and it was clean.
Before this occurrence I would have the same opinion as Fun71. I never had a problem. Maybe the shell gas would be better. Here in Long Island NY the gas all comes from the same storage tanks no matter what brand. They then add additives for each brand. Maybe they don't add them at all. Who knows what you're getting?
We don't have many Shell stations here. I'm adding an ethanol additive to be sure. Thanks for all the input.