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  #16  
Old September 24th, 2019, 09:47
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Re: Low idle while coming to complete stop?

Quote:
Originally Posted by MickeyS View Post
that's almost exactly my attack plan once the weather cools down here. get that damn manifold off swap the mounts and super deep clean the fuel/intake system. I will order a can of that bk44. looks like good stuff the injectors are 180k miles old, but I have run chevron and seafood through it before.
That is your problem... they are not made for seafood, they are made for gas.
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  #17  
Old September 26th, 2019, 16:13
MickeyS MickeyS is offline
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Re: Low idle while coming to complete stop?

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Originally Posted by old_man View Post
If it is an automatic transmission, the clutch in the torque converter could be staying locked.
How would I figure out if this is happening? I'm a bit dense and don't know much about the transmission. It happens only when coming to a dead stop and then idles up to 740ish in D, and nicely in park 750-800.

I confirmed the maf vacuum elbow was good today and spent a good ten minutes spraying carb cleaner all around the throttle body/injector area and whatever other vacuum lines I could see in the engine bay, and found no leaks whatsoever.
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  #18  
Old September 28th, 2019, 15:23
lawsoncl lawsoncl is offline
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Re: Low idle while coming to complete stop?

A quick check of the t/c unlock would be to drive along steady at highway speeds, and lightly hit the brake with your left foot. You should see the converter unlock and the rpm jump up a bit. Pretty rare to have it not unlocking though, and the usual problem is that it's not locking in the higher gears due to a bad solenoid or bad switch on the brake pedal, or sometimes a bad TPS.
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  #19  
Old September 28th, 2019, 23:33
MickeyS MickeyS is offline
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Re: Low idle while coming to complete stop?

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Originally Posted by lawsoncl View Post
A quick check of the t/c unlock would be to drive along steady at highway speeds, and lightly hit the brake with your left foot. You should see the converter unlock and the rpm jump up a bit. Pretty rare to have it not unlocking though, and the usual problem is that it's not locking in the higher gears due to a bad solenoid or bad switch on the brake pedal, or sometimes a bad TPS.
I understand now how it should work. Just took it for a jaunt on the freeway and the converter unlocked properly. I still have a suspicion this is a fuel/injector/wiring/voltage issue. at night with lights on, cigarette accessories going, voltage can dip to 13.4-13.5 where the rpms can go as low as 650.
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  #20  
Old September 29th, 2019, 07:38
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Re: Low idle while coming to complete stop?

I am still wondering if you installed a Cheap crappy Chinese IAC or a genuine Jeep IAC ?


Quote:
Originally Posted by MickeyS View Post
...... voltage can dip to 13.4-13.5 where the rpms can go as low as 650.
That is normal. The alternator typically does not achieve full voltage until about 1500 rpm.
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Last edited by Tim_MN; September 29th, 2019 at 07:42.
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  #21  
Old September 29th, 2019, 08:35
MickeyS MickeyS is offline
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Re: Low idle while coming to complete stop?

no genuine iac now
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  #22  
Old September 29th, 2019, 13:06
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Re: Low idle while coming to complete stop?

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Originally Posted by MickeyS View Post
no genuine iac now
There are plenty Chevy's that uses the same IAC. That would be a good place to look.
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  #23  
Old October 29th, 2019, 12:57
MickeyS MickeyS is offline
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Re: Low idle while coming to complete stop?

Replaced injector o rings, super deep cleaned throttled body and IAC, OEM IAC and NEW TPS... no change. ran bk22 through. One time idled super low coming to a stop, into the 500s, wouldn't recover until I hit the gas. since then, idle at stop drops to 690 and then recovers. then vacillates between 720-750.

Assuming the issue is with the transmission or the engine at this point and will be doing compression this weekend.
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  #24  
Old October 29th, 2019, 16:15
Down under Down under is offline
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Re: Low idle while coming to complete stop?

Sounds silly, but I had same once.
Ended up being loose battery terminal!
Ran fine under load!
Died in the bum at idol.
Clean and see what happens.
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  #25  
Old October 29th, 2019, 16:49
MickeyS MickeyS is offline
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Re: Low idle while coming to complete stop?

thanks. I wish it was that simple, but I've replaced the battery and terminals this year.
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  #26  
Old November 17th, 2019, 13:28
MickeyS MickeyS is offline
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Re: Low idle while coming to complete stop?

Well my vacuum at the manifold is fluctuating pretty good. I don't have any reason to think the gauge is broken but I borrowed it from a friend who had never used it.

https://youtu.be/gnb12BEDUfI

Low and erratic, web search seems to diagnose valve springs. I will try to get ahold of another gauge to do a dummy check.

hottest (#6) plug looks like/there is a bit of oil on the first threads. these have about 4k miles on them.

https://youtu.be/K5qyzRsDhlc
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  #27  
Old November 17th, 2019, 13:37
MickeyS MickeyS is offline
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Re: Low idle while coming to complete stop?

Fuel pressure is a perfect 49

another view of a plug with what looks like oil on the threads. it does read as oil on paper towel. I don't seem to be visibly burning any or missing much oil from the crankcase, not sure if this is from a previous leaking valve cover or what.

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  #28  
Old November 17th, 2019, 14:23
MickeyS MickeyS is offline
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Re: Low idle while coming to complete stop?

In edition to the rapid fluctuation on the vacuum needle I'm noticing a good amount of exhaust pulsation and some spray out of the tailpipe but no smoke.
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  #29  
Old November 17th, 2019, 15:07
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Re: Low idle while coming to complete stop?

I wonder if #6 injector isn't opening.
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  #30  
Old November 17th, 2019, 15:16
MickeyS MickeyS is offline
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Re: Low idle while coming to complete stop?

they all kinda look like that. 6 just looks a bit hotter.
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