Rough Idle

[njRegal86]

I have a rough idle on my Olds 307 motor, in my 86 Regal, and I think its because of the 10% Ethanol in the gas nowadays. How can I fix it?

 

[CAPERKEV]

sell it an buy a horse an buggy,lol the new gas is gonna be a problem for these old crates, yank motor an build one capable of using this new sh*t gas, or just deal with it, it sucks but what other choice do we have?

 

[njRegal86]

well I'm certainly not gonna get a horse and buggy haha, but my auto teacher told me I could pour fuel stabilizer into the mix. What do you think about that. And he also said "dry gas"

 

[bill]

Try stepping up a grade on the gas. Unleaded regular has more corn syrup in it than the higher grades do. Also, I use the stabil additive for ethanol which helps reduce the moisture content that ethanol is so famous for. Old gas with corn syrup is no good...so if your car sits a lot, that might explain the rough idle. I also use seafoam to help stabilize the fuel because my ride sits more than it goes....lol.

 

[jmt455]

Are you sure it's not a vacuum leak?
Check all the vacuum hoses (including all of the the cruise control, power brake booster and vapor canister lines).
A leaky vacuum hose, badly worn throttle shaft holes or a leak at the carb base gasket will mess up idle quality and cause stumbling and hesitation.

 

[njRegal86]

I don't think I have a vaccum leak, and i drive it everyday. Can I sea-foam with gas already in the tank?

 

[njRegal86]

what do you guys think

 

[Bowiemontecarlo86]

I always fill the tank all the way and adda whole bottle of sea foam. Also when's the last time your fuel filter got changed. this new sh*t gas cloges up filters sogotta keep up on the maintenance. But I would check all your vac houses and lines just to make sure they good.

 

[njRegal86]

thanks for the tip, and i did my fuel filter like in June 2011. and now that I think of it I've been hearing this wierd sort of hissing noise from under the hood. Could that be a vaccum leak?

 

[Phoenyx]

Yeah sounds to me like you have a vacuum leak.

A trick someone once told me: With engine warm, remove air cleaner. Give the carb a little bit of throttle so that you can (with your finger( push the choke flap closed, and let go of the throttle. If the engine continues to run, then there is a vacuum leak.