carb question/idle problem
03-13-2009, 05:06 PM
#1
2nd Gear Member
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Posts: 228
carb question/idle problem
when my car is at idle when in park or neutral it idles fine but when i put it in a drive gear the rpm's drop really low and it wants to die, so i adjusted the idle screw and it idles fine in drive now but the only way i could achieve that was to raise the idle and its really loud and annoying when im parked now, the carb is a 650cfm holly any suggestions?
03-13-2009, 05:38 PM
#2
5th Gear Member
Join Date: Apr 2007
Location: Texas Hill Country
Posts: 2,100
Idle on an automatic car should be set and tuned with the car in gear. You will need a buddy or a tree to hold the car still while you do this. You still follow normal idle tune procedure, just with the car in gear.
03-13-2009, 07:41 PM
#4
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Join Date: Mar 2004
Location: Az
Posts: 1,090
O.K. I'll go out on the limb here. It sounds like you are running lean and are going about fixing it the wrong way. I am thinking you have a vacuum leak but, try this first....With the engine off, turn your "mixture" screws all the way in...then back them out 2 turns. Start the motor..While you have it idling in park, set the idle at 800. (about). Now, start turning the mixture screws "in" (clockwise), 1/4 turn at a time....evenly.(wait 20 or 30 seconds between turns) This is where your ears come in. Turn the screws in until you hear the motor change "tone"..it may even start to run rough. Once you reach this point, turn the screws back out 1/4 turn.
Now, set your idle in gear, then see what it does in park. (or you could set it in park and see what it does in gear.) If it is the same as before, you probably have a vacuum leak.
Now, set your idle in gear, then see what it does in park. (or you could set it in park and see what it does in gear.) If it is the same as before, you probably have a vacuum leak.
03-13-2009, 07:43 PM
#5
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i had my friend help me with it thats why it idles fine in gear now just really high in park or neutral, and im not sure about the vacuum or the stall, the guy i bought it from had the engine built for him and the tranny is out of a 72' mustang
03-13-2009, 07:44 PM
#6
2nd Gear Member
Thread Starter
Join Date: Apr 2008
Location:
Posts: 228
O.K. I'll go out on the limb here. It sounds like you are running lean and are going about fixing it the wrong way. I am thinking you have a vacuum leak but, try this first....With the engine off, turn your "mixture" screws all the way in...then back them out 2 turns. Start the motor..While you have it idling in park, set the idle at 800. (about). Now, start turning the mixture screws "in" (clockwise), 1/4 turn at a time....evenly.(wait 20 or 30 seconds between turns) This is where your ears come in. Turn the screws in until you hear the motor change "tone"..it may even start to run rough. Once you reach this point, turn the screws back out 1/4 turn.
Now, set your idle in gear, then see what it does in park. (or you could set it in park and see what it does in gear.) If it is the same as before, you probably have a vacuum leak.
Now, set your idle in gear, then see what it does in park. (or you could set it in park and see what it does in gear.) If it is the same as before, you probably have a vacuum leak.
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