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-   -   Stutter on idle (http://www.wranglerforum.com/f274/stutter-on-idle-239274.html)

MI JeepSkate 04-30-2013 01:48 PM

Stutter on idle
 
I like to have my RMP below 1000 on a start up (cold or warm) before I engage to drive and get on my way. This afternoon I did exactly what I do every start up but this time I got a stutter. It went down below 1000 like a bog and went back up to 1000 before it did the same thing and then nothing but a smooth idle. I didn't have my foot on any pedals, and there's only 36K on the jeep. Any ideas?

Raziel 04-30-2013 02:37 PM

Are you some how forcing it to start below that at start up? Because it goes that high when cold to get to OP temp faster.

WatchThis! 04-30-2013 03:24 PM

Quote:

Originally Posted by Raziel (Post 3702048)
Are you some how forcing it to start below that at start up? Because it goes that high when cold to get to OP temp faster.

They don't actually do that to get up to temp faster, it is because a cold motor runs ruff and misses at low RPMs when cold. The programs are set to keep it at an RPM that it won't spit and sputter.

Say you bust it off and the markers are set at 120, 160, and 180.
While the engine temp is below 120 the programming might be set to keep it at 1200 RPM. Once the temp gets up to 160 the RPMs migh drop down to 1100 and then down to what ever you have your OP temp idol at when you temp gets over 180 degrees.

The last value is what sets the idol of an engine, so if you want to change you idol you just change the last value.

The OP's computer might have just had a hiccup and missed one of the marker points.

MI JeepSkate 04-30-2013 06:01 PM

an old mechanic friend of mine told me to never start up and drive. give the motor time to get oil inside if it and warmed up and be on your way. so thats why i do it. maybe i worded it wrong, i always let the RPM drop below 1000 before i start driving, and today out of the blue it just about stalled on its own but re caught itself and idled fine

JKWrangler2012 04-30-2013 06:18 PM

God love our crappy gasoline. Might wana run some Lucas fuel lube. It's not a detergent, rather a lubricant replacing what is stripped out for emissions and such. Early build 2012 23k and going strong! Lucas every 1k for me. I've seen the pictures of the engines that have had head jobs and I'm astonished at the carbon build up at just 10k! Unreal!

GotNet 04-30-2013 06:22 PM

Mine did that twice a couple weeks ago. New left head fixed it. Can't see on my phone what motor you have.

Raziel 05-01-2013 12:49 PM

Which in turns, it's set that way to get the OP temp up faster.

WatchThis! 05-01-2013 01:11 PM

Quote:

Originally Posted by Raziel (Post 3706331)
Which in turns, it's set that way to get the OP temp up faster.

Nope. It is to keep the engine running smooth till it gets up to temp, not get it up to temp faster. A few hundred RPMs don't make a huge difference in how fast the temp comes up anyways.

MI JeepSkate 05-06-2013 09:24 PM

its the 3.8, i put seafoam it on friday, and now it makes a whine noise? getting better mileage but it just sounds different


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