Well I have a problem with my car it idles high when its in park, it stays at about 20k and when I drop it into drive it goes down to 1.3k doesn't matter if the engine is cold or hot. I even adjusted the ISC and still idles high no vaccum leaks new pcv valve/ hoses/ primary choke/secondary choke. Is there a proper way to adjust the ISC and chokes? The engine doesn't hesitate, burns rubber fine. Its a 85 cutlass brougham v6 231. Whats the normal revs in park and drive? Thanks.
Have problem with carb high idle or?
- Thread starter cuttytime1985
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There is a "factory" way to set the idles, but you can do it by ear/feel. The fast idle on your carb is a simple adjusting screw. The slow idle is adjusted with both the stop screw on the solenoid controlled by the computer, there is also a set screw used to set the speed when the throttle lever is not in contact with the solenoid. You can get a shop manual or browse the web for your carb to see where all the idle set screws are. I never set them to where they say, I go just a tad faster on the slow idle, a tad slower on the fast idle. Some of those fast idles wind up to 2500 RPM or more when the engine is cold, which might have been fine when the engine was new but not the best thing to do with an older engine. 1800-2000 is more than enough to keep it running cold. I set slow idles to about 600 in drive. You'll notice on these cars the RPM's drop quite a bit between park/neutral and drive/reverse.
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I think my problem is with the one thats controlled by the computer because if i disconnect the computer the idle drop to normal, so what do I have to do for that one?
check the vacuum lines for the front and rear vacuum breaks. check the choke as well. both of mine were cracked and the carb didnt like this one bit.
i had a problem where my fast idle would not kick down and this was during the summer months... it wasnt on the fastest setting but was on the 3rd step i believe. god it was so annoying. the engine would get hot, its amazing how a couple hundred RPM can make a difference like that.
my new carb doesnt do that but ive had fits with a partly open choke door and air flow into the engine as well as setting the fast idle. the factory setting is 2200 RPM for my engine and now that ive set it pretty high (i think just shy of 2200) the engine runs better and i think i got the choke door opening issue fixed with a minor adjustment.
MY emission label said to only set the highest fast idle to 2200 RPM. the rest are set automatically as its all about the choke after that. but this is for my engine, always refer to your emission label under the hood on the fan shroud. it tells you what the timing should be and the fast idle as well as a schematic of the vacuum lines and emission stuff.
i had a problem where my fast idle would not kick down and this was during the summer months... it wasnt on the fastest setting but was on the 3rd step i believe. god it was so annoying. the engine would get hot, its amazing how a couple hundred RPM can make a difference like that.
my new carb doesnt do that but ive had fits with a partly open choke door and air flow into the engine as well as setting the fast idle. the factory setting is 2200 RPM for my engine and now that ive set it pretty high (i think just shy of 2200) the engine runs better and i think i got the choke door opening issue fixed with a minor adjustment.
MY emission label said to only set the highest fast idle to 2200 RPM. the rest are set automatically as its all about the choke after that. but this is for my engine, always refer to your emission label under the hood on the fan shroud. it tells you what the timing should be and the fast idle as well as a schematic of the vacuum lines and emission stuff.
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