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12-09-2003, 07:09 PM | #1 |
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Join Date: Dec 2003
Posts: 69
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New here and got a question
I picked up an 85 about 4 weeks ago and have been working on it non stop but this most current problem is driving me insane.
its a 305 with a q-jet, and when im sitting at idle it runs fine and all the way up to about 1/2 throttle it runs fine after that it sputters and has no get up what so ever, it feels like its either getting too much gas or not enough. MY new plan is to start building a motor for it but i'd like to get this one running alright just for now. |
12-09-2003, 07:20 PM | #2 |
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Join Date: Oct 2002
Location: Edmond, OK
Posts: 5,904
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welcome to our addiction, feel free to fill out more of your info, so we know abit more about you. sorry i have no input on your problem, my carb did that briefly as well, but worked itself out in a few days... had me stumped. mine did it around 1600 rpm...
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Jon 1982 Chevy Silverado 350/th350.... RETIRED 1993 Jeep XJ 2 door(Cherokee) 4wd 4.0ltr/AX-15 (5spd)/NP231 .... Oklahoma Roll Call |
12-09-2003, 07:57 PM | #3 |
You get what you pay for
Join Date: Dec 1999
Location: Cherryville, NC
Posts: 4,798
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Does it ever catch up and go or just fall flat on it's face and never recover? Is it doing this when you punch it or is it when you slowly press the pedal? Is it the back barrels or front or both?
It's real hard to diagnois problems like this over the net, but work with us and we will help all we can. It could be a bunch of things causing this. Most folks think when something like this is wrong, it has to be the carb. Reason is, it's the first thing they see when the hood is raised. Could be a fuel filter needs changing. Could be the carb needs a rebuild. Could be it needs some fine tuning.
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Mike 1985 Chevy C-10 |
12-09-2003, 09:10 PM | #4 |
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Join Date: Dec 2003
Posts: 69
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Well, when i slowly press it down from a dead stop when it gets about 3/4 throttle it fall flat on its face and feels slower than when i give it half throttle, and a punch it from a dead stop it gets to about 1500 rpm there abouts and falls flat again
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85 swb, 5/7, 20" smoothie 2's Last edited by Kendhul; 12-09-2003 at 09:12 PM. |
12-09-2003, 10:58 PM | #5 |
You get what you pay for
Join Date: Dec 1999
Location: Cherryville, NC
Posts: 4,798
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Sounds to me like your secondary air valve spring is missing, loose, or broken.
http://www.73-87.com/garage/myqjet.htm Scroll down to the section on setting the tension. Stock carbs are set to around 7/8 of a full turn. Just something to check. |
12-10-2003, 12:04 AM | #6 |
5 day ban, learn to behave.
Join Date: Nov 2002
Location: san diego, ca
Posts: 683
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if the engine is in dire need of a tuneup, you will also get similar symptoms.. when was the last time the plugs, wires, cap, and rotor were replaced?
my guess is that the engine should be tuned up completely, including fuel filter(s), then re-do the carb as for swervin's suggestion of the secondary air flap, cant he just open it manually with his fingers and see how hard it slams shut? It should have just enough force to close on its own, not too hard not too soft.. eh? mike |
12-10-2003, 01:06 AM | #7 | |
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Join Date: Dec 2003
Posts: 69
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Quote:
hmmm, that could be why my SAV is just hanging open...
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85 swb, 5/7, 20" smoothie 2's |
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