NCSU90XJ
NAXJA Forum User
- Location
- Wilmington, NC
I am trying to diagnose a high idle situation on my 90 XJ Cherokee. When ambient air temps are above about 80 degree, it idles fine (around 700-800 rmp) after warm up. When ambient air temps go below 80, the idle speed increases with cooler temps. The idle speed can be upwards of 1700 rpm when it is below say 40 degree ambient air temp. I have rulled out the IAC valve because I have started the engine and let the idle settle down then unplugged the the connector to the IAC and then engine slowly starts to idle faster and faster as the engine warms up (so the IAC valve is not opening further, which would be letting more air through the IAC port). Could unmetered air be somehow be entering the engine after the warm up period to cause the increased idle speed. What is throwing me a curve is the the idle speed is direcly realated to air temp. Thanks for any suggestions.
Andy
Andy