Got Shell 93 Octane and now barely idles 1973 Dart 340

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TRWRacing said:
Ok. Not my preferred method, but I would rather not change the manifold. Do you think it's water in the gas? The exhaust is sputtering and I have to enrich the mixture screws close to 3 turns just to keep it idling. Before this problem started they were out 1.5 turns

Thanks,
Eric
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You don't have to change the manifold. You can use the plate I linked to.
 
RustyRatRod said:
You don't have to change the manifold. You can use the plate I linked to.
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Yes, that was my plan. My concern is there is water in the gas as well that I bought and within 3 miles car starts running bad.
 
I believe isopropyl alcohol is so saturated it cannot absorb any water. The pure alcohol you can get from a propane store is different. Iso will solubilize some of it. Instead get some Watersorb at the local boat shop.
 
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TRWRacing said:
Yes, that was my plan. My concern is there is water in the gas as well that I bought and within 3 miles car starts running bad.
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It could well be. I would confirm that one way or the other though before I made any changes. It seems all your woes came right after you put gas in.
 
So RRR you are saying that plate will make a squarebore carb work with a spreadbore manifold? Or is that manifold not a spreadbore. Inquiring minds.... Thanks
 
Without that plate the gasket will not seal around the secondary section of the intake. The manifold has both bolt patterns if it is aftermarket. If it is the factory cast and your carb doesn't have both bolt patterns then you need the thicker adapter plate that uses additional bolts that come up for the square pattern. Without seeing the manifold top we can't be sure if the thin plate will work but if it has not been modified from stock it is likely the thin one wont let the primaries open.
 
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mguner said:
Without that plate the gasket will not seal around the secondary section of the intake. The manifold has both bolt patterns if it is aftermarket. If it is the factory cast and your carb doesn't have both bolt patterns then you need the thicker adapter plate that uses additional bolts that come up for the square pattern.
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This was my thinking as well.
 
RustyRatRod said:
It could well be. I would confirm that one way or the other though before I made any changes. It seems all your woes came right after you put gas in.
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I am taking it by a guy that I have had work on it in the past. In case the tank needs to be dropped. I called the IL Dept of AG to report a possible water contamination. Until then try to siphon out via tube what's there into 10 gal containers? Turning out the screws to enrich A/F made no difference. Only going lean to almost seating them made it die.
 
for water in the gas tank I have used a product called HEET® Gas-line Antifreeze & Water Remover with good results.
 
TRWRacing said:
It's factory stock manifold.
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Yeah that's the adapter to use but I would use long studs in the original locations and use the inner pattern on the carb. That should provide less distortion of the adapter and better clamping of the gaskets.
 
Ok may have mis spoke, everyone calls it isopropal in the great white north.

What is ISO-HEET® brand? How does it work?


ISO-HEET® brand contains isopropanol and special gas additives including Fuel Injector Cleaner. When ISO-HEET® brand is added to the fuel tank, this formula remains in the solution with the gasoline, and absorbs five times more than regular gas-line antifreeze. Any water in the gas tank mixes with the ISO-HEET® brand, preventing the water from freezing in winter. ISO-HEET® brand also removes water and condensation in warm, wet weather. Then the entire mixture of gasoline, ISO-HEET® brand and water are burned during combustion inside the engine. ISO-HEET® brand cleans fuel injectors and carburetors for fast starts and smooth-running engines year round
 
HEET works good. Oreilly has it for like 3.99.
 
mguner said:
Yeah that's the adapter to use but I would use long studs in the original locations and use the inner pattern on the carb. That should provide less distortion of the adapter and better clamping of the gaskets.
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That is what I was thinking, but why did the previous owner RTV two gaskets on the intake side then the adapter and a thin gasket to the carb. The previous owner air cleaner was so high it was gouging into the underside of the hood. I changed to to a lower profile because of that.
 
if u have an air compressor blow air into tank from filler end with rag wrapped around it for a ''seal'' and undo fuel line at fuel pump, doesnt take too long to empty tank this way
 
TRWRacing said:
That is what I was thinking, but why did the previous owner RTV two gaskets on the intake side then the adapter and a thin gasket to the carb. The previous owner air cleaner was so high it was gouging into the underside of the hood. I changed to to a lower profile because of that.
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No accounting for shade tree actions.... RTV is never a good thing to use around fuel and fuel vapor unless it is a specific formula. He may have tried to use old gaskets that had already been imprinted with another carbs pattern. That is a common cause of vacuum leaks and is often how base plate ears get broken off of carbs when guys try to cinch it down to stop the leak. You can reuse the gaskets sometimes if they are indexed correctly and off the same carb and spacer setup only!
 
As a side note I have "cheated" using a belt sander on the thicker insulator type gaskets to remove the pattern and start fresh but that is a desperate act for "git-er-done" situations.
 
I don't have an air compressor. The previous tank full about 2-3 weeks ago I had used Lucas Ethanol conditioner which was 3/4 full added. I didn't use it this time as I only added 8 gallons and I was on my way home from work.
 
mine..... factory cast intake. I used the 3/8 TQ base gasket on the intake, then the flat adapter plate, then a thin square bore base gasket. My intake is also "hogged" out on the primary side so the front primary's on the carb have no restriction. I have since added carb studs.... :)
 
Is HEET something that would make a difference with this? It's weird that exhaust sounds bad, which was the first symptom that I noticed, but I guess related to the idle.
 
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TRWRacing said:
Is HEET something that would make a difference with this? It's weird that exhaust sounds bad, which was the first symptom that I noticed, but I guess related to the idle.
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If you think it is water in the gas, Heet is a cheap fix that may help you out as long as there is more gas then there is water in your tank. I put it in and let it sit over night, it mixes with the gas and absorbs the water.
 
d1970 said:
If you think it is water in the gas, Heet is a cheap fix that may help you out as long as there is more gas then there is water in your tank. I put it in and let it sit over night, it mixes with the gas and absorbs the water.
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8 gallons of the previous tank was good and I filled up of 8 gallons that could possibly be "contaminated"
 
Lucas has product that says it neutralizes poor quality fuel
 
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