1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

My car won't idle correctly and dies if I let go off the gas pedal.

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Old 06-23-07, 07:14 PM
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My car won't idle correctly and dies if I let go off the gas pedal.

So as titled stated... my car won't stay idle... it idles at 500 and it will slowly dies. I give it a little gas then it'd stay up a bit and repeat the same.

What happened was...

I had a fuel leak from the fuel hose going to the carb... so I replaced that and it's working fine. I was running low on gas... and my driveway is not a straight road so the gas was probably not feeding in to stay idle so it died on my driveway... I poured in gas... tried to start it and it wouldn't start even I let the fuel pump on for a bit. So I tried to start it again and again... and one of the starter cable was burnt... there were smoke coming out so I finally gave up. Next day, I got that fixed, started the car up and it started fine but the car sounded a little rich... it ran well though so I went to the gas station to fill in some gas. The car wouldn't start back up after I got it filled up... it was odd... so I left it there until the next morning and fix it with my bro... first thing we checked was to see if the spark plugs were wet and they were, kinda burnt too... but we flushed the float boat and got the plugs dry and clean so we can get the car home... it started up... at first the car didn't sound like it's going to die... so I thought it's fine until I reach up to an intersection... my car started to idle at 500 rpm and the car was jerking when it's not even moving, so I got it home and it died on me right at the moment when I was fully stopped. Took out the plugs and its burnt again... so I just ordered new plugs... had to wait 3-4 days so I got Autolite instead today. The car started up but I had to jump it... then after the choke .... the car started to want to die again at 500 RPM... I don't know why this is happening... it was running fine until the car died cause it ran out of gas.

Me, my bro, and my friend thought about maybe it's the cap and rotor? But they are like new condition... spark plugs wire are fine, my battery is about 6 months old... we can't think of anything else...
Can you guys please tell me why this is happening??? Thanks!
Old 06-23-07, 08:49 PM
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Does it miss at constant throttle or deceleration...if so search "shutter valve" its a very easy bypass fix.
Old 06-23-07, 11:41 PM
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Sounds like when the tank got empty, the ful pump sucked up the juck at the bottom of the tank. Check/replace your fuel filter.
Old 06-24-07, 01:53 AM
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Besides those... what else can it be?
Old 06-24-07, 01:55 AM
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I have a YAW carb by the way... if that helps or not... what is the shutter valve?
Old 06-25-07, 11:28 AM
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Bump!
Old 06-25-07, 05:17 PM
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Its a device to increase economy when off the throttle, do a search...
Old 06-26-07, 11:23 AM
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The rat nest is removed... so what's the shutter valve? Is there still one when the rat nest is removed? I can't find anything on the device for increase economy... =\
Old 06-27-07, 07:54 PM
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I replaced the fuel filters... both of them... still doing the same thing... what's next? Should I try the idle screw?
Old 06-27-07, 08:19 PM
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a truck i had it was throtle body and it would flood it self out mayb a jet or something is stuck wide open
Old 06-27-07, 09:31 PM
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I was looking for the idle screws... but I can't... I wanna try to play with those and see what I can come out with... it's a YAW carb... just to let you know... I was wondering if the shutter valve is there? The rat nest is gone.





Old 06-28-07, 02:20 AM
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im not too familiar with different carbs and rats nest but i had idle issues and i had my air control valve changed and that solved everything. i thought i saw a mixture screw in the third pic, the one with the spring on it
Old 06-28-07, 11:08 AM
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Ok... I found the idle speed screw last night and played with it to the correct RPM. It worked! I thought the car is going to be all good, so I took it out for a spin... it ran pretty smooth for a mile or so then when I was coming to a stop... the car started to idle very low again... I tried very hard to give it gas to pump the engine back up... it didn't work and it died. We had to push the car back home... now I have no idea what can happen? I checked the float boat and it seems to be filled again! I don't know why... is it time to check the needle and seat now or... what should I do before that? Something might be more simple?
Old 07-16-07, 09:52 PM
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What fuel pressure are you running?
Have you changed the fuel filter, as asked priviously?
Have you tested for vacuum leaks?
Your valve is gone from the manifold, which is good, but how thick is that cover? Is it sealed with Hylomar, or something similar, or not? The plate looks thin to me.
I think there's a combination of problems here. First one is that your idle speed was too low, which you've fixed.

You REALLY need to get a Haynes manual for your car. It will tell you all the troubleshooting basics.
Old 07-16-07, 11:28 PM
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Originally Posted by Sterling
What fuel pressure are you running?
Have you changed the fuel filter, as asked priviously?
Have you tested for vacuum leaks?
Your valve is gone from the manifold, which is good, but how thick is that cover? Is it sealed with Hylomar, or something similar, or not? The plate looks thin to me.
I think there's a combination of problems here. First one is that your idle speed was too low, which you've fixed.

You REALLY need to get a Haynes manual for your car. It will tell you all the troubleshooting basics.
I am running 2.5psi for the fuel pressure, i replaced both of the fuel filters, and there is no vaccum leak (i sprayed the exterior of the carb, but the engine didn't bog at all). I have the haynes manual and i think i tried everything they suggested for this problem.
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