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Lq4 SOMETIMES dies on idle after start, braking etc

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Old 03-04-2014, 07:13 PM
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I had a semilal problem when i disconected my battery. Cleaned the throttle body and every thing was good after that. Hope that helps
Old 03-05-2014, 03:03 PM
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Originally Posted by BlackGMC
Next time take note of the engine temp. I think it has todo with your desired sairflow table being off at lower ect temps.
Could be, but I have seen it happen when the engine is warm, but maybe not 180* warm. Temps have been below zero most nights and nothing really above freezing since November. I will have to see what happens when it warms up this spring. Its been fine for the last week, until lunch today when it wouldnt idle and would barely restart.

What could cause that all of the sudden? I've ran the same tune/set up for 4 years and the problem is new as of a few months ago. After I changed the FPR it seems to have gotten better, as it has only happened a handful of times vs every day, but it still happens.
Old 03-07-2014, 03:15 PM
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Have you checked the coil packs?

Could it be vapor locking at some point?

If its random I'm still betting it is a connection error somewhere that randomly loses signal and slowly shuts the motor down.

during the time my temp sensor was half way holding on, when it would lose connection it would choke the motor and kill it fast, also slammed the transmission like it was wanting to lock up and quit rotating.
Old 03-07-2014, 04:14 PM
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everything looks good, no misses, good everything. It runs perfect when its good, when its bad, its bad. It never happens on the fly, its always on a restart. i could drive for 4 hours and be fine, stop for gas, start it and it would run bad for that next 4 hours on idle.
Old 03-07-2014, 05:09 PM
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So some days you can turn it on and off all day and other "random" days this issue will occur?

both O2 sensors are good, able to log the fuel trims when it does this?

MAF and tb clean, sensors are good?

Fuel pump, filter, injectors?

Sorry for any obvious things to do just trying to brainstorm lol
Old 03-23-2014, 03:58 PM
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Well it ran good for a few weeks and then ran like **** again. I swapped the IAC from my other truck and i think its fixed. Wierd thing is that datalogging never showed a problem with the IAC. I've had a problem ever since i put the engine in that it would idle down low sometimes going from D to R or vice versa. This took care of that as well as my stalling. My TB is clean as hell, but when I pulled the IAC it was caked with oil and ****. Must have never taken it out to clean it. All is well now.
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