Proper RPM
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Proper RPM
I have a 95 F150 with the 300 inline six. I noticed that on cold start ups the idle rpm is about 1500 and then it drops to about 1000 and stays right around there when warm. What is the correct idle rpms for operating temp?
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Wicky,
Your truck isn't too far off the mark. It's supposed to idle faster right after startup, run that way for a minute two, then drop back to baseline idle. Which is about 700-800 rpm I think. If your baseline idle is higher than that, check the IAC or cold temp sensor. The IAC is easy to find/replace...it controls air/fuel mixture for idling. The cold temp sensor tells the computer what temp the coolant is, so it can control running variables throughout the operating heat range. Might also want to pull the codes...if either IAC or cold temp sensor is out of line, they will set a code. Best way to gauge idle rpms is with a tach.
Your truck isn't too far off the mark. It's supposed to idle faster right after startup, run that way for a minute two, then drop back to baseline idle. Which is about 700-800 rpm I think. If your baseline idle is higher than that, check the IAC or cold temp sensor. The IAC is easy to find/replace...it controls air/fuel mixture for idling. The cold temp sensor tells the computer what temp the coolant is, so it can control running variables throughout the operating heat range. Might also want to pull the codes...if either IAC or cold temp sensor is out of line, they will set a code. Best way to gauge idle rpms is with a tach.
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I have a tach, and I can tell idle speed by ear better than watching my tach, long long story. Anyways, I have already done the IAC due to an accident with a wrench and a friend. No codes stored or thrown only thing left is coolant sensor or....
