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Old 06-08-2009, 08:11 PM   #22 (permalink)
The Atomic Ass
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Join Date: Oct 2008
Location: Mason, OH
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Overland - '24 Nissan Versa S 5MT
90 day: 37.88 mpg (US)
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Quote:
Originally Posted by theunchosen View Post
Thats interesting.

So you've already looked at the throttle body and it snaps shut after you release the throttle, but it continues to stay revved up. I'm not entirely sure how thats possible. The ECU is going to inject roughly a gram of fuel for 15 grams of air. . .and if the throttle is closed it just means you get the same power as you would at idle(it wouldn't rev high) but you inject a ton of fuel most of which gets burned in the cat. If the air isn't getting in somewhere somehow it won't stay revved up like that, you can't burn more fuel than air allows.

Next suggestion I think Christ already said, watch the throttle body after someone shuts it down and watch to see if it moves after they let up and after it "snaps" shut. If it twitches to a less open position the ECU is telling it to hold open for some reason or another.
From working on the '90 Pontiac I used to own I know, the IAC has enough control to hit redline in neutral. Not like I can find the IAC in this truck, though.

Also, the choke on my Ninja 250 was not a choke at all, but an enriching circuit. With the throttle fully closed it could be revved to 5-6K RPM. Just from dumping fuel into the engine.

I've also tested without the CC cable attached, no change. (the CC module is the only way I am aware that the computer can directly control the TB)
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Last edited by The Atomic Ass; 06-08-2009 at 08:19 PM..
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