'06 Optima Stalling issue

[Sprocketus]

Daughter's '04 Optima, replaced the motor about a year ago after a broken timing belt trashed the motor. Has been running great ever since until recently. It will stall with no notice, still has vehicle power and will turn over but not firing. Wait a little while then it runs, till a while later then it stalls again. Shop replaced the crank position sensor and it ran ok for a week, then failed again. Same shop said cam position sensor was bad, replaced that twice since the first one appeared to be bad out of the box. Anyway, now it will run ok till it warms up again, then starts running very rough and then dies (still in the shop). Tech told me that the scanner still calls out the CPS but also something about the injector firing order is way off, causing it to run rough. He is recommending that I take it to a Kia dealer and have then re-flash the ECM and then it will work ok. I am waiting for him to call me back with the current scanner codes before I call the dealer. Timing belt was checked, crank sensor as well, not sure where to go with it, as I think the computer re-flash is a crap shoot. Thanks for any help you can offer, it is much appreciated.

[DavesSpectra]

Is it an "04" or an "06" ??? You said both... The engines (2.7L) are different.
You have made no mention of possible stored OBDII codes that usually are stored when an "event" happens... This would help greatly....
You are our "eyes", "ears", and "hands" and without this feedback it's hard to help you...
Needed:
Codes
Type engine (2.4L 4 cyl or 2.7L V6)
Mileage on the car (body)
Mileage on the engine (when installed and currently)

One thought.... With the engine being replaced wiring harnesses have been disturbed and moved...(and possibly replaced and/or modified). A misplaced harness or hose can/could wear through and cause intermittent "problems".. The "dressing"/"routing" (placement) of the wires during the engine change can happen. Lot's of posts on the web about worn vacuum hoses and damaged harnesses causing problems. Simple stress relieving brackets left out during re-assembly may allow wires/hoses to touch hot areas or move back and forth wearing through them.. A simple plug/socket connection in the harness left loose may also bring you problems....
There are thousands of possibilities...We need to address...Information will help.
Dave

[Sprocketus]

Originally Posted by DavesSpectra

Is it an "04" or an "06" ??? You said both... The engines (2.7L) are different.
You have made no mention of possible stored OBDII codes that usually are stored when an "event" happens... This would help greatly....
You are our "eyes", "ears", and "hands" and without this feedback it's hard to help you...
Needed:
Codes
Type engine (2.4L 4 cyl or 2.7L V6)
Mileage on the car (body)
Mileage on the engine (when installed and currently)

One thought.... With the engine being replaced wiring harnesses have been disturbed and moved...(and possibly replaced and/or modified). A misplaced harness or hose can/could wear through and cause intermittent "problems".. The "dressing"/"routing" (placement) of the wires during the engine change can happen. Lot's of posts on the web about worn vacuum hoses and damaged harnesses causing problems. Simple stress relieving brackets left out during re-assembly may allow wires/hoses to touch hot areas or move back and forth wearing through them.. A simple plug/socket connection in the harness left loose may also bring you problems....
There are thousands of possibilities...We need to address...Information will help.
Dave

Thanks for your post. It is an '06 2.4L dohc 4 cyl motor, replacement motor has been in for about 18 months. Approx 180K miles on car, approx 85K on replacement motor. I am waiting on the shop to call me back with the current codes, if any. They looked at the harnesses and said everything look ok. The crank sensor came with a new harness and they assured me that it was installed correctly. He never answered my question about fuel pressure or an injector test while the problem was occurring though. Hope that helps.

[DavesSpectra]

Check the wiring harness that connects to the crank sensor... I believe I've read where it is routed it may rub the engine block and wear through the insulation causing problems.
I may be "off base" on this one but check to be sure...
With that many miles on the "body"/fuel tank you may have a worn out fuel pump that may be becoming intermittent and dropping off line... The pump is a DC motor with brushes that will eventually wear to the point where it will quit or become intermittent.
A realtime reading of short term fuel trim when it's having problems would show the pressure dropping... An OBDII reader/scanner attached while you drive would show this.. It would still "run" with a bad injector...but poorly... There are also some KNOWN problems with engine/fuel/ignition relays under the hood causing headaches like yours.
These may or may not throw "codes"..
Dave

[Sprocketus]

Ok, here is the current status: The car will start COLD, runs fine, accelerates well, but when it gets warmed up is when it will not accelerate. Here are the following codes he gets on the freeze frame sensor (his words):

P0342 Cam position sensor voltage low
P0102 Air flow circuit low input
P0200 Intake circuit malfunction

If it is driveable I will take it to a friend's house to look it over as he is a pretty good technician.

[Sprocketus]

Just found that there is no injector pulse or spark on any cylinder after the motor warms up. Any ideas? Thanks