Holley 500 problem

[matthones]

Fellas (& gals),

Been a long time since I've posted. Long story short, truck sat for about 2 years with almost no fuel in the tank. What fuel was in there turned bad so I pulled it, cleaned it out, got a new fuel pump and filter, charged the battery, and of course no light off, but the engine bay reeked of fuel. Pulled the air filter to see what I could see, turned engine over again and see fuel spurting out of the fuel bowl vent.

My question is this, is this a simple pull the carb and clean it out issue since it had bad gas in it as well? If so, am I going to have to get it re-tuned once disassembled or is it easier than that?

2nd question, I never had any of the vacuum ports connected to my dizzy, is this an issue or do most of you run it this way?

3rd question, all gas stations around here sell 10% ethanol fuel, but I did find 1 station that has pure gas, 91 octane only though. Is 91 octane ok or will I have to adjust the timing? I was previously running 87 octane.

Thanks in advance

Matt

[FetchMeAPepsi]

Originally Posted by matthones

Fellas (& gals),

Been a long time since I've posted. Long story short, truck sat for about 2 years with almost no fuel in the tank. What fuel was in there turned bad so I pulled it, cleaned it out, got a new fuel pump and filter, charged the battery, and of course no light off, but the engine bay reeked of fuel. Pulled the air filter to see what I could see, turned engine over again and see fuel spurting out of the fuel bowl vent.

My question is this, is this a simple pull the carb and clean it out issue since it had bad gas in it as well? If so, am I going to have to get it re-tuned once disassembled or is it easier than that?

2nd question, I never had any of the vacuum ports connected to my dizzy, is this an issue or do most of you run it this way?

3rd question, all gas stations around here sell 10% ethanol fuel, but I did find 1 station that has pure gas, 91 octane only though. Is 91 octane ok or will I have to adjust the timing? I was previously running 87 octane.

Thanks in advance

Matt

Welcome (back) to the club!

1st question: Probably your float needle is gummed up. I'd tear it apart and look about rebuilding the carb. It's an easy job and you probably need to do it anyway. You can get USA made rebuild kits from daytonaparts.com or you can get a kit from Autozone and just clean and re-use your float needle. The chinese ones in the kits now dont close properly (badly tapered).
As far as re-tuning as long as you don't bend any linkage or monkey with the screws on the front of the carb you should be OK to fire it up and go.


2nt question: all of my vacuum ports are connected so the timing advance stays working. Maybe you have HEI? IDK about that one. Someone else will have to help there.

3rd question: Octane is how the keep the gas from causing engine clattering. It wont affect your truck one way or another. Its mainly for the newer cars that have to have real high compression. We could probably run 50 octane and be fine

[turbobill]

1) The Holley carb is easy to pull the needle and seat on and see if it is free. A stuck or heavy float requires pullung the bowl.

2) The distributor vacuum advance should be plumbed to manifold vacuum. This will improve economy and driveability.

3) While these engines don't require 91 octane fuel, the non ethanol fuel is better for economy and doesn't have any of the harmful effects of ethanol on components in the fuel system. it will also make the engine more detonation resistant and it will tolerate a few extra degrees of ignition timing. I use it in everything gasoline powered around here.

[tommr]

if you can pressurize the fuel line and rap the side of the bowl lightly with a dead blow hammer you should be able to free up the needle. clean gas should clean a varnished up seat. if you can get it freed up and it doesn't run well you may need to pull it apart. 2 weeks ago went to fire up our 401M powered bus that sat for 2 years. no squirt. rapped the side of the Stromberg and nothing. turned on the electric fuel pump and rapped it once. heard the bowl fill and it fired right up.

[matthones]

Fellas, thanks for the advice. Put the rubber mallet against the carb a few times and no more fuel volcano out the top, unfortunately noticed a leak from the bottom of the carb now. Got a rebuild kit coming in tomorrow so gonna replace some seals and what not and try again in the afternoon. I guess the only good news is that all the fuel I smell is really fresh, got rid of all that old varnished stuff.

[tommr]

the varnished fuel can wreak havoc with valve guides as well. best to get rid of it. good luck

[matthones]

Got the Holley rebuild kit and it all looks good, no more leaks and the the carb appears to be working just fine. Just started another thread in the electrical section for a no spark issue I have now. If it's not one thing it's another.