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Unread 12-08-2011, 05:36 PM   #1
Registered User
1996 ZJ 
Join Date: Nov 2009
Location: michigan
Posts: 969
RPM at engine start

My 4.0 ZJ has generally ran up to 1500 rpm upon starting and settles down to 700 within about 2 seconds. The last couple weeks, it just starts up and is at 700 RPM without the run-up after firing. The engine has 300K miles and I doubt the IAC has ever been looked at. Was it starting normally before, or is the new startup correct? Is this caused by the IAC?

96 ZJ Laredo, 4.0, 242, 230K
95 ZJ Limited, 4.0, 242, 140K
98 XJ Sport, 4.0, 231, 140K
All work well
bigbill888 is offline   Reply With Quote Quick reply to this message
Unread 12-08-2011, 05:41 PM   #2
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1998 ZJ 
Join Date: Aug 2011
Location: The Abyss, Italy
Posts: 18,554
Clean or replace the IAC/ throttlebody and run some seafoam through the engine.
PolkaPower is offline   Reply With Quote Quick reply to this message

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