jgaz 750 Posted October 13, 2015 Does your 4.0L have an IAC control motor that consists of a stepper motor and a pintle valve? I don't remember what your throttle body consists of. On my 01 4.7L Dakota I was able to cure an erratic idle my removing the above type IAC motor and spraying throttle body cleaner into the orific that is regulated by the pintle valve. I found throttle body cleaner seemed to work better then carb cleaner for this type of work. May not be applicable to your situation just thought I'd share. Share this post Link to post Share on other sites
In-A-Rut 3 Posted October 14, 2015 Just by some sea foam and follow the instruction. Share this post Link to post Share on other sites
theksmith 5,778 Posted October 14, 2015 i'm partial to the DIY combustion cleaners that you use while the engine is running: http://offroadpassport.com/forum/showpost.php?p=27955&postcount=776 Share this post Link to post Share on other sites
scottL 185 Posted October 14, 2015 Does your 4.0L have an IAC control motor that consists of a stepper motor and a pintle valve? I don't remember what your throttle body consists of. On my 01 4.7L Dakota I was able to cure an erratic idle my removing the above type IAC motor and spraying throttle body cleaner into the orific that is regulated by the pintle valve. I found throttle body cleaner seemed to work better then carb cleaner for this type of work. May not be applicable to your situation just thought I'd share. Thanks for sharing. I believe it does, here's a photo from when I replaced the MAP, TPC & IAC three weeks ago They were all dirty with brown sludge on them. I also cleaned out the throttle body with a can of "Air intake & throttle body cleaner" from Autozone. I did not remove the throttle body though, just sprayed cleaner all over it and down the open throttle blade. Share this post Link to post Share on other sites
scottL 185 Posted October 14, 2015 Just by some sea foam and follow the instruction. Think I will have to try this, have you done this to your new(er) Cherokee yet? i'm partial to the DIY combustion cleaners that you use while the engine is running: http://offroadpassport.com/forum/showpost.php?p=27955&postcount=776 The Mopar ccc was only $10 on Amazon & I had leftover gift credits from a survey I did at work so free w/ free shipping is bargain enough for me to give it a shot. Should arrive this Friday and I will report back what happens. K, do you remember noticing a difference in RPM after cleaning yours? Share this post Link to post Share on other sites
jgaz 750 Posted October 14, 2015 I found it necessary, on my Dakota, to remove the throttle body unit and spray cleaner into every passage on the unit that I could get the straw into. Use eye protection! Share this post Link to post Share on other sites
scottL 185 Posted October 15, 2015 I found it necessary, on my Dakota, to remove the throttle body unit and spray cleaner into every passage on the unit that I could get the straw into. Use eye protection!Ok, assuming i'll need to pick up another throttle body gasket too just in case. I will try removing the throttle body after doing the combustion chamber cleaner. If neither of those two fix the situation, I guess I'll move on to the fuel system service. Share this post Link to post Share on other sites
theksmith 5,778 Posted October 15, 2015 so is it still idling too low every day, or irregular idle or what? Share this post Link to post Share on other sites
scottL 185 Posted October 15, 2015 still idling too low every day Everyday after a good heat soak the tach needle still hovers somewhere between the 2nd & 3rd hash mark, closer to the 1st. Still trying to figure out what rpm's the factory set those hash marks to represent, but yeah, closer to the 1st thin hash mark above the thick white one that I've always considered to be zero. Guessing maybe 300-450rpms? Since I'm usually just driving around town short distances the hypochondriac in me is concerned that it very well could die again out on the trail or out in the middle of nowhere or both. Say for example on a trail in the area between Moab, Monticello & Tuba City. That's almost the land equivalent of The Bermuda Triangle speaking in terms of civilization. I require solid reliability on the trail & especially in the middle of native indian reservation land, where the only thing you'll see on certain stretches of highway are stray dogs. I'm keeping my fingers crossed this combustion chamber cleaner works. Do you remember if it affected the idle qualities after running it through your WJ? Share this post Link to post Share on other sites
theksmith 5,778 Posted October 15, 2015 Everyday after a good heat soak the tach needle still hovers somewhere between the 2nd & 3rd hash mark, closer to the 1st. Still trying to figure out what rpm's the factory set those hash marks to represent, but yeah, closer to the 1st thin hash mark above the thick white one that I've always considered to be zero. Guessing maybe 300-450rpms? Since I'm usually just driving around town short distances the hypochondriac in me is concerned that it very well could die again out on the trail or out in the middle of nowhere or both. Say for example on a trail in the area between Moab, Monticello & Tuba City. That's almost the land equivalent of The Bermuda Triangle speaking in terms of civilization. I require solid reliability on the trail & especially in the middle of native indian reservation land, where the only thing you'll see on certain stretches of highway are stray dogs. I'm keeping my fingers crossed this combustion chamber cleaner works. Do you remember if it affected the idle qualities after running it through your WJ? i don't remember it affecting idle, but i don't think i had idle problems when i used it. what is the factory spec on yours for idle after warm-up? Share this post Link to post Share on other sites
