High idle. Just swapped my 2.5 TB for a 4.0 TB - Page 2 - JeepForum.com

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post #16 of 23 Old 01-19-2012, 07:11 PM Thread Starter
ROTTEN
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Sprayed all around with carb cleaner and no difference
Installed a new Tps no difference
Reset the computer no difference

BUT when I turn the wheels while idling the rpms quick jump up 600 and back down
What is that?

Tomorrow im putting the 2.5 tb back on

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post #17 of 23 Old 01-19-2012, 09:35 PM
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The jump in idle comes from the computer. It's the same mechanism that makes your idle jump when you turn the air conditioning on.

As for your high idle, I agree with the previous poster that it probably is a result of you not opening up the hole in the intake manifold. I don't see the point in putting on a 4.0 TB if you don't open up the intake. You won't flow any more air (which is the whole point of the swap). More airflow = more HP.

“The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed.” ― Robert M. Pirsig, Zen And The Art Of Motorcycle Maintenance: An Inquiry Into Values
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post #18 of 23 Old 01-19-2012, 10:13 PM Thread Starter
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Fair enough!

Off she goes tomorrow
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post #19 of 23 Old 01-19-2012, 10:26 PM
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Quote:
Originally Posted by GrantYJ View Post
The jump in idle comes from the computer. It's the same mechanism that makes your idle jump when you turn the air conditioning on.

As for your high idle, I agree with the previous poster that it probably is a result of you not opening up the hole in the intake manifold. I don't see the point in putting on a 4.0 TB if you don't open up the intake. You won't flow any more air (which is the whole point of the swap). More airflow = more HP.
I did nothing to my manifold, that is not the problem.

Back Road Jeepin

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post #20 of 23 Old 01-19-2012, 10:55 PM
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post #21 of 23 Old 01-20-2012, 09:26 AM Thread Starter
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Ok we can let this subject sleep the rest of the winter. 2.5 is back on and it's running fine

Few thoughts
I did not change the iac housing. I didn't understand until I took the tb off what the housing was
Also I did not grind the intake

So one of those two things is the culprit


One big change is loss of power. The 4.0 tb Definantly makes a difference.
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post #22 of 23 Old 01-20-2012, 09:57 AM
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So power increase?

I go to college and I drive a Jeep.
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post #23 of 23 Old 01-20-2012, 10:06 AM Thread Starter
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The power increase is noticeable

I really suggest it. 75 in 5th with new 32s. Before I could barely do 65
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