5.9L Gas, will just randomly shut off while idling. Usually is fine, tried to let it run the other morning and came back outside to a non running truck, haha. Also seems to be stalling at lights and such, not always, just sometimes. Truck sat for 5 years, but seems to run fine. Also, last night revved it up a bit to see if it would do anything weird - seems to stutter at just about 4k RPM.

NEW:
Fuel Pump Assembly
Dist. Cap / Rotor
Plugs
Wires
IAC
Air filter
Upper and Lower TB Gaskets
Cleaned the TB real well
And tons of other unrelated crap.

I have 0 plenum symptoms, cat does not seem to be clogged, no power loss on driving. I'm leaning towards CKP or CMP, or partially failing coil. Surprisingly, Upon doing the wires, I found an old coil bolted to the motor, and the one that is currently being used, just sitting up in the intake valley. I still need to remove the old, and bolt the 'new' one to the motor. Surprised it works at all without being case grounded. Since it does run so well with it the way it is, I'm going to say that is not the problem.

Anyone else have this issue? TPS shows about 12.5% at idle, which is a little weird. Though, I don't think these problems would present with a bad TPS, since its only at idle, and apparently - 4k RPM (regardless of where the throttle is).

No codes are presenting.

 

What brand IAC did you get? Connections back there look good? Clean and tight?

 

Good question - I have no idea. Whatever the parts store had in stock - I presume I went with the cheapest option available (hahah). And yes, clean and tight. It was originally idling HORRIBLY. Replaced the IAC, and did the full tune up and now it runs like a champ (save for these little.. episodes...)...

 

I would try and do some data logging if you can, paying attention to TPS values, and IAC counts when it acts up. Might be intermittent TPS...... or, might just be a bad IAC.

 

Good thinking - I'll take some rips this afternoon with the wife logging. I'm sure she'll love that! Always forget about my live data features.

 

UPDATE!

Replaced the TPS, MAP sensors, still no good. Picked up a CKP and CMP (pickup), and new Coil - but have since returned the CKP and CMP in favor of front and rear o2 Sensors. After datalogging, it looks like the events are happening as soon as the fuel system goes into a closed loop state - indicating o2 issues - and funny enough, I'm getting an o2 code (P0132) now. I had it early in the process, but it went away.

https://docs.google.com/file/d/0B6tT...it?usp=sharing

^^ Datalog, red is trigger, orange is event (so far as I can tell... no idea how long each frame is, but this is when it felt like it was happening, numbers confirming), yellow is maybe event, prob not - and green is all good in the hood.

If anyone sees something odd other than what I'm describing, please let me know.

 

Short term fuel trims do seem excessive. I think O2's are a good start.

What's range on the O2 sensors? 0 to 1? or +1 to -1?

 

Having a bitch of a time removing these things. PB isn't helping, heat isnt helping, o2 sockets aren't helping (neither is the limited amount of room to work in). I might have to actually bring this turd to an exhaust shop and let them deal with it.

o2's in general, or these specific o2s? I think a general range is 0-1.5V. Or close to it. Probably should be more like 0-1. Obv. the closer to 0 the more o2 present.

 

try the 50/50 acetone and ATF mix as a penetrating oil.

 

Will do -- Also, after looking at that datalog, it appears I drive this truck like a grandmother. If it were my WRX, MPH would be like 55-60, RPM 4-6k, hahaha. Maybe the wife was right, I should become a truck guy - less trouble on the road.