Rough idle and crazy headlights/wipers

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Jun 23, 2008 | 07:33 AM

#21

Thmprr

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Joined: Dec 2005

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From: . New Zealand

Quote:

Originally Posted by rosselot

My first thought was bad gas. Now I'm thinking my first guess might be right. I put a 1/2 tank of gas in at a Shell station about 30 minutes before this started (93 octane). What's the best way to see if this is the problem? Can I add something to the tank? Should I pour new gas down the carb to see if there is a change? Everything on the carb seems to be working and the fuel flow seems fine too.

Thanks, Andy

That's a coincidence, it wouldn't be water in the gas would it?
This happened to a fellow Corvette owner last weekend, and his was flooding all the time, barely idling and running real rich. We fixed it using some stuff we gat from an Auto parts shop which removes water and passes it through the system harmlessly. May be worth a shot to try that. They say that you never fill up within 30mins of the tanker topping the tanks up. All gas stations have a percentage of water in the bottom of their tanks.

Jun 23, 2008 | 09:52 PM

#22

Billy Baroo

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From: Brecksville, OH

Thmprr,
Thanks for the info; that sounds just like my problem. I'll run over to the auto parts shop tomorrow and give it a shot. Anyone recommend a particular brand? The only question I still have is why my vacuum system was drained (both headlights and wiper door are open).
Thanks, Andy

Jun 24, 2008 | 08:34 AM

#23

jdp6000

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From: Aurora Ontario

I think your car has a vaccum canister. It should be between the head lights. You will see the vac lines running to it. Follow them. It looks like a large coffee tin. The system is suppose to generate vaccum. Its held in that cannister. When you pull the light switch vaccum is cut off to the lights and they rise. When you push the switch in vaccum is drawn from the canister and they go down. Your system is depleted of all vaccum if these things are staying up and the wiper door is staying open. You still need to eliminate a vaccum leak but I think you did that didn't you? Did you pull the hose from the block and plug it? When I say plug i mean at the block. If you do that and you still get the rough idle its not a leak in the vaccum system and you can now look at other things.

Jim

Jun 24, 2008 | 08:37 AM

#24

jdp6000

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From: Aurora Ontario

Before i forget another source of a vaccum leak from the intake is the PCV valve. Do you have a pcv? Change the valve. Its only about $4.

Jim

Jun 24, 2008 | 10:21 AM

#25

tommyleea

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Joined: Apr 2006

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From: Warrensburg MO

If you hear a hissing sound, and haven't traced it down yet, I would do that first. If you can keep it running, take a short piece of heater hose, put it up to your ear, and start tracing. Once you get to the hissing noise it will be very clear. My 2 cents spent. Cheers..

Tommy

Jun 24, 2008 | 11:16 PM

#26

Billy Baroo

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From: Brecksville, OH

I already tried plugging the valve coming out of the manifold and there was no change or improvement. I really don't think its a vacuum problem; I think that the low vacuum is a symptom of a mechanical problem or bad gas. When I get it running it runs rich.

I added dry gas and it didn't help (Heet brand). I changed my coil and it didn't help. I changed the plugs and it didn't help much - it does idle without me feathering the pedal but it is still a rough idle and I can't rev the engine. The only other thing I can think of doing is changing the fuel filter. Any more thoughts? Am I wrong to dismiss the vacuum as the problem?
Thanks, Andy

Jun 24, 2008 | 11:32 PM

#27

indy99

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From: the land of a never ending frame-off resto-mod. May Visa have mercy on my soul.

Check your timing and see if there is a change. You may have jumped a tooth on the timing cain/sprocket.

Jul 23, 2008 | 12:58 AM

#28

Billy Baroo

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From: Brecksville, OH

It was the points!!

After about a month looking for a vacuum leak that didn't exist I discovered that my points were bad. The reason I thought there was a vacuum leak was because of the loud sucking sound coming from the carb. This of course was the normal sound that the carb makes but you don't hear it because of the engine rev; which I wasn't getting. This past weekend I rubbed sandpaper between the contacts on the points and the engine sounded great for about 10 seconds. Today I put in the new points and gapped them .019 and the car runs better than ever.

Thanks to everyone for their suggestions. I just wish I had explained the problem a little better so I wouldn't have wasted anyone's time. The good new is that I'm back on the road and I can move on to my next project; Hurst shifter install.

-Andy

Last edited by Billy Baroo; Jul 23, 2008 at 04:51 PM.