97 ZJ V8 JGC Wont idle when cold

Greetings,

My 1997 ZJ will not idle when cold.

It happened 2 weeks ago and we cleaned the battery terminals, checked grounds, and it all seemed good. After the cleaning truck ran fine. it has about 75,000 miles on it an i take good care of it.

But this morning it was about 37 degrees, and it wont idle unless you run it at about 1500 RPM.

After warming up , engine would idle normally. Have checked the alternator voltage, no codes appear other than the 55 code.

Any pointer appreciated, regards,

james

Reply to
jamest
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Excerpt from the '96 ZJ manual engine diagnosis 'Rough Idle"

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While not required a thorough cleaning of the throttle body assemble, Idle air passages, fuel system and injectors wouldn't hurt and only costs $12-$20 depending on brands and how thorough you need or want to clean.

Reply to
billy ray

billy ray is the man!! - Thanks

$10 - Poured in a bottle of fuel system/injector cleaner into a full tank of gas . Seemd a little better... $10 - Sprayed in TB cleaner and took it out for run on the freeway. Better yet... $80 - Picked up a new IAC Motor and changed it ( the old one was carbon city ). Sprayed a little TB cleaner in the IAC air passage and wiped out a lot of carbon from there. WOW..

It didnt run this smooth the day I bought it. Amazing, best $100 i ever spent on it.

Thanks Aga> Excerpt from the '96 ZJ manual engine diagnosis 'Rough Idle"

Reply to
jamest

Reply to
Will Honea

Thanks, I got the truck in 2000, its a 97, i figured a new IAC motor wasnt to gross an indulgance. How long a drill bit?

I will look up the Idle bypass port/Jet screw in the shop manual/Alldata. I am not a mechanic so things take a little longer:-)

thx, james

Will H> You could probably have saved $80 by cleaning the old IAC and the

Reply to
jamest

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