'99 V10 idle problem
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'99 V10 idle problem
I have a '99 V10 that idles bad. A lot of times when I fire it up in the morning it'll hit 2000-2400 rpm's stay for a little while and gradually drop down to normal. When it's cold out it's a lot worse. Could it be a back pressure problem because of the 4" cat back exhaust with no catacylic converter? Or is it something else?
It especially sucks trying to plow snow with it, the truck wants to take off when you come to a stop (idle will stay up until truck is put in a different gear). Also, ne night it was -25 below 0 and when I fired it up the rpms hit 2500 and kept climbing, so I threw it in gear to drop the rpm's. Truck was fine the first winter I plowed snow with the 4" exhaust on it.
I also know that my tranny slips because when it shifts up the rpm's jump 100-200. But I'm noticing now that when it down shifts going slow, (probably 15-30mph) once it down shifts the rpms will jump up. Is that the tranny slipping or would that be part of the idle problem?
Only mods are K&N air filter, cold air intake, and 4" cat back.
Any help/suggestions is very appreciated.
It especially sucks trying to plow snow with it, the truck wants to take off when you come to a stop (idle will stay up until truck is put in a different gear). Also, ne night it was -25 below 0 and when I fired it up the rpms hit 2500 and kept climbing, so I threw it in gear to drop the rpm's. Truck was fine the first winter I plowed snow with the 4" exhaust on it.
I also know that my tranny slips because when it shifts up the rpm's jump 100-200. But I'm noticing now that when it down shifts going slow, (probably 15-30mph) once it down shifts the rpms will jump up. Is that the tranny slipping or would that be part of the idle problem?
Only mods are K&N air filter, cold air intake, and 4" cat back.
Any help/suggestions is very appreciated.
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My V10 is on its 3rd IAC. Both times it went out, it ran great, but it would not idle at all. I also think it may be something else. But, cleaning the IAC would be a good idea since it always seems to need it. Just buy a couple of extra bolts and a gasket before you try and reinstall it, you'll probably lose at least one bolt down in the engine trying to get to it to put them back in.
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Joined: Jul 2002
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From: Long Island USA
Check for vacuum leaks. High idle is usually caused by unlimited intake air, and not restricted exhaust.
The PCV plumbing elbow right at the throttle body is known to crack.
The PCV plumbing elbow right at the throttle body is known to crack.
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FTE Leadership Emeritus
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The IAC is on the back of the throttle body.
The PVC elbow is on the passenger side of the throttle body. Follow the tubing from the PCV valve in the passenger-side valve cover to the throttle body. The elbow where that tube connects to the throttle body usually cracks.
The PVC elbow is on the passenger side of the throttle body. Follow the tubing from the PCV valve in the passenger-side valve cover to the throttle body. The elbow where that tube connects to the throttle body usually cracks.
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