Thread: Strange grit-like substance in carburetor

Tweet

Once per season since I put my car on the road in 1992, I have to dismantle my Edelbrock/Carter AFB and hose it out with Gunk carburetor cleaner to remove the grit-like material that seems to form in the float bowls and then passes into the delivery system. The symptoms are low and irregular idle, a severe flat spot above idle, and a difficulty in maintaining a steady driving speed. The first time I did this, I bought a rebuild kit to get fresh gaskets, etc. and also found that both float levels were off with one way out of spec. They've been fine since then, and I'm still using the same gaskets. After this cleansing, it runs like a top - easy starting, smooth idle and steady running.

Since last October, I've driven the car less than 100 miles, but I start it once per month and run it until the engine is fully warmed-up. I do this mostly to drive out moisture, keep the seals working, and charge the battery. I've found that this makes a huge difference when spring roles around.

I use an electric fuel pump with a high-quality fuel filter. I can't figure out what's causing this, or what it is. I say "grit-like", because it doesn't seem to be sand, although that's about the particle size, and I when I rub it between my fingers it will disintegrate.

I typically put less than 3,000 miles on the car each season, which is only about 7 tanks of fuel. I fill up at a name brand filling station, but seldom the same brand each time (I have no gasoline brand loyalty).

Any ideas at to what this mystery substance is, and/or what's causing it to form or appear in my carburetor? I'm beginning to suspect that the fuel line is deteriorating, but I've never heard of that happening.

For extra credit: what's the trick to re-assembling these carburetor bodies? I have to jiggle the upper body until it will fully lower onto the lower body. It feels like something is holding the two halves apart on one point, but I can't figure out what that point is.

I'll bet the mystery substance is all the garbage they put in the gasoline nowadays after it evaporates.... As far as why it won't drop down I bet it's the metering rods...joe

Probably Ethanol; if you leave it sit in the carb for any amount of time it will eat up everything and leave a nice mess in the bottom of the carb bowl. I have hauled fuel for the last 20 years and we have started putting it back in the gas again to make to oil companies more money. And it does bring down emmisions but it also likes to eat up carbs. I have to buy a carb for my 72 vette because of it, too. the rest of my car are now are fuel injected even my 70 ford pick up.
Kurt

Kurt said exactly what I was going to say. We just had this discussion on another forum and the poster said he called a fuel tank maker and they are no longer making tanks from Poly because the ethenol is eating them up.

We were seeing lots of this in the marine repair industry I worked in, ethenol was eating up fuel lines, plastic tanks, and even aluminum and steel tanks were being damaged by it.

I would bet that is what you have going on.

Don

What do you put in the fuel tank when you park it for storage??? I've always had very good luck using Sta-Bil in the gas when it's gonna be parked for awhile! With only 10% ethanol, doubt it's causing the problem...it's just the low quality fuel, doesn't even matter where you buy it.. We run E-90 in a couple drag cars, when we store them for the winter we put a couple gallons of Av Gas with Sta-Bil in it and run the car long enough to work it through the carb before we shut it down.

I don't add anything for storage, I just fill it with fresh gas before its long winter nap. During the winter I also use that gas by siphoning it off periodically for power tools (leaf blower, snow plow, chainsaw).

In the case I described here, I found the crud in the carburetor early in the season. In other years, I haven't noticed the symptoms until later, sometimes mid-summer. Mostly, though it is after a long period of dis-use.

Too much crud in gasoline these days... I'd use Sta-Bil in it when ever it's in storage... Used it in everything around here when it's stored, never any problems.

I take it that probably you have your filter mounted between the tank and pump in the rear of the car????

Put an inline filter up front just before the carb.

Jerry

I will give you guy an idea how corrosive the ethanol is.
We have site glasses where we can see the fuel going in and out of the tank when we load or unload the tanker. With-in two weeks of starting to add ethanol to the fuel we had to replace all the site glass and gasgets. The gasgets got ate up and the site glass which was made of plexie type glass all craked and were braking apart. Now we use real glass and metal gasgets instead of the paper gasgets we had usd for years. The metal gasgets even needs replaced every six months or so now. So the ethanol is some bad stuff. The Sta-Bil will definetly help, my buddy runs a yard were folks store their motor homes and they all use that Sta-Bil and they don't have any problems.
Unfortunatly for my Vette carb I found out about Sta-Bil to late, it's all ate up inside.
Oh and I hate to say it but not all of the tanker drives get their blends right so you could also get what we call a hot load with more ethanol then it was supposed to have.
I know this because thats what I did for years when I was not training other drivers. I would go around trying to fix other drivers mistakes or pumping tanks out that could not be fixed.
Kurt

E-10 is a problem. We started seeing problems a couple years ago on boats and the manufacturers of the outboard and inboard motors started sending out advisory after advisory, warning that we were going to see it get worse as time went on. At first it was just that fuel got gummy after a short time sitting. It used to be that 6 months or a year without stabilizer was no problem, but we were seeing carb plugging after only 2-3 months. Customers were irate and saying we were not rebuilding their carbs correctly, so we posted the letters from Mercruiser, Yamaha, OMC, etc on the wall so they could read it for themselves.

Then, after a while we started seeing more serious problems. We were finding strange looking stuff in carbs and fuel injection systems. Fuel related problems became the number one repair we were doing on a daily basis. One customer was towed in with a boat that he had installed a new poly tank in only two weeks earlier, and the inside of the tank looked like it was sandblasted. Particles of the plastic were found in the entire fuel system and carb bowl. That was not an isolated case, we were also seeing aluminum and (especially) fiberglass tanks where the insides were dissolving or being pitted.

I've had lots of conversations with the Tech guys at all of the major boat motor manufacturers, and none had good things to say about ethanol fuel, or had solutions to fix the problems in older engines. Their common reply was "Tell your customers to expect more frequent fuel system repairs than they have ever seen."

Supposedly, cars built after something like 1980 are ok with the new fuels, but since we rodders use lots of older parts maybe that is why we occasionally see what is being described here.

Don

I guess the ethanol in Florida must be a lot worse at 10% then the stuff we've been running here for the last 20+ years...

I've seen so many problems blamed on ethanol, lots of them came down to bad contaminents in the gas, a dirty fuel system (yes, ethanol will knock that stuff loose), improper (or no) fuel filter, you name it...

Or, maybe we've just learned how to set things up so the fuel system is compatible with the ethanol in it....but I sure do like the extra octane for a few cents less then regular without ethanol...we can still get that here...

Don't know what to say about the poly tank deal....both the race cars have plastic tanks running on E-90 and my old shop truck has a poly tank and has been on E-85 for better then 5 years now...

Anyway, if your stuck with it in your area there's really nothing to do other then make sure your fuel system is clean and has a good filter!!!!

But, I'm sure I'll remain in the minority being pro-ethanol.... but I guess as long as I can run 13:1 compression on the street, and pull up to the pump and put in my 106 octane E-85 for 30 to 40 cents per gallon less then 88 octane regular I just don't mind having to maintain the fuel system a bit more often......

I doubt you can even find a carb kit in the store now that does not contain ethanol compatible gaskets and seals unless it's an old, dusty NOS kit that's been on the shelf for too many years anyway.... Perhaps some of the problems just getting into the 10% ethanol stuff is that there nasty, dirty tanks are getting cleaned out and that's the residue winding up in the carbs and causing problems???????


PS--Your government at work again...the stuff prior to ethanol ended up being a carcinogen!!!!

I'm with Dave on this one, in Mn we had the same ethanol in our gas as Dave for around 20 yrs. I have used it in everything from 2.0 ci gas R/C planes, lawn mowers, every day cars, Hotrods, to Blown 454 in our boat, and have never had a problem related to it, ever!


Pat

Dave and Pat, from knowing both of you for a long time on this forum, I know what you guys post always is the truth and factual. I respect your opinions. I'm also glad you both (and some others) have had such good success with it. The only thing I can offer is what I have been seeing in the marine industry I was in for the past 25 or so years. For us it has become a major pain. Here are some other viewpoints on the subject:

http://boatingsailing.suite101.com/a...ms_for_boaters

http://www2.highlandstoday.com/conte...oblem-ethanol/

http://www.fuel-testers.com/ethanol_...dvantages.html

http://www.slate.com/id/2122961
--------------------------------------------------------------------------
Another problem with ethanol blended fuel is "Phase Separation". Here is a brief explanation of that issue:

What is ?phase separation?, and how do I deal with it?
If significant amounts of water are present in a fuel tank with gasoline that contains ethanol, the water will be drawn into the fuel until the saturation point is reached for the three-component mixture of water + gasoline + ethanol. Beyond this level of water, phase separation could cause most of the ethanol and water to separate from the bulk fuel and drop to the bottom of the tank, leaving gasoline with a significantly reduced level of ethanol in the upper phase. If the lower phase of water and ethanol is large enough to reach the fuel inlet, it could be pumped directly to the engine and cause significant problems. Even if the ethanol water phase at the bottom of the tank is not drawn into the fuel inlet, the reduced ethanol level of the fuel reduces the octane rating by as much as 3 octane numbers, which could result in engine problems.

--------------------------------------------------------------------------

So maybe my opinion is clouded because the boat engines I am experienced in are more prone to problems from ethanol than car motors. Cars tend to use up their fuel faster than boats, maybe keeping it fresh enough to not cause the degree of problems boaters have been experiencing. That might be why some hot rodders are also having these problems as our rods tend to sit idle for longer periods than our daily drivers.

Just a thought.

Don

Don, we can all find quotes and stats for anything or any opinion.

If ethanol is that big of a problem, then don't run it. If it's mandatory in the fuel in Florida, then the only thing to do is learn to work with it. It takes a better fuel system and a higher level of maintenance. I was around boats awhile myself, most of the owners I met could give a hoot about maintaining anything, so ethanol isn't going to work well for them until they become a bit educated on how to maintain (or have maintenance done) on their boat.

No amount of statistics will change anything about ethanol, and it doesn't look like the government is going to cease mandating it anytime soon so the only thing left to do about it is learn to deal with it's charachteristics....

Oh yeah, Sta-Bil also works well with ethanol blended fuels....

Not all the fuel problems come from ethanol, the stuff out of the pump is just plain trash and with or without ethanol it's gonna start turning to trash in around 30 days.... As I mentioned earlier, we drain the E-90 and dump a gallon of AvGas in the tank and run it long enough to get it through the carb circuits. When it's time to go racing, we fill it with E-90 and go race, no problems.

Sure, it's a hassle. But it's just the old hot rodding deal of taking what's available and making the best out of it that you can. Not even the government can put a stop to that!!!!!

bought a mighty max p/u in 86 new after a couple of years the truck would stop running when you were going down the road.the fuel filter was cloging up with rust from the fuel tank.so bought a case of fuel filters and every time it quit running i would change the filter the truck would start right up and i would be ok until the next time.i got real good at changine the filter had it down to 45 seconds.i tryed buying a new tank but mity never had a replace ment for this tank.the 87s were redisgned and would not fit.