Yet another update!
I worked on the Kia out of frustration today, and noticed the following: when it starts up, INSTANTLY there is a smoky/hazy vapor coming out of the front coolant passage. Like it runs for 3 seconds and vapor is oozing out (where the coolant hose and sensor housing bolt to.) So I smell the smoke and it is STRAIGHT exhaust smelling, which made me start thinking that the head gasket may be blown, despite the good compression test.
Anyways, I pulled the head off tonight, and there's a few fishy spots that look to have been leaking, both into the coolant passages, and between the cylinders, which may have contributed to the multitude of problems this thing is experiencing. The rear piston (#4) is very dark in color, and the pistons get ever so lighter until you're at piston #1. Seems really tell tale of a head gasket.
Can't hurt to have a new on one anyways! The pistons look beautiful, the bore still has full hone marks, and the head is undamaged. No nicks on anything, or any signs of crap being sucked through. Since this thing had a new radiator in it, I'm wondering if it was ever overheated, and blew the head gasket. It would explain the new rad, and why it has run worse, and worse the more I've run it. Also, the head bolts were REALLY REALLY loose when it took them off. I didn't even need a breaker bar. A few almost spun right out (the two front ones.)
Having the head out also lets me get the all the connections in the back of the block, and de-grease and clean them WELL.
You have been busy.. Glad to hear you have located the issue, and agree w/ your suspicion that the previous owner had a head gasket issue, given the new replacement radiator..
Before reinstalling I would highly recommend checking the cylinder head for warping: based on your findings of the condition of the head gasket when pulled,
This youtube video may be helpful to you:
If you have access to a reputable machine shop in your area, you may want to consider bringing the head to them to check: a (true) machinist straight edge should be used to check, it may be less expensive to bring to a shop to check, vs. purchasing the straight edge,
Please keep us posted, looking forward to hearing the Sporty is repaired,
*Still checking for those wiring harness items: I have them archived (somewhere), will get posted ASAP / this weekend..
Sounds good! A good friend of mine runs a high performance engine company that decks heads and blocks, I'll let him look at it and see what he thinks. Hopefully it isn't warped, but if it is then it'll be getting milled or a new one will be sourced. I'm hoping it's the headgasket, but a new one can't hurt! (and eliminate one more potential issue)
Have you checked fuel pressure while engine is running?
What if the regulator is stuck and over pressurizing the fuel rail?
Did you check the ECT splice (as mentioned above)?
And to answer your question about testing wiring harness... just make a long set of test leads and check resistance from corresponding ECU pins to sensor plugs. One at a time and have a helper wiggle/shake harness to see if it changes reading.
I have never seen this SB but it could be the cause of a lot of early Sportage problems with sensors and ECM related problems that show up on these forums.
Quite a "find"...
We might consider start asking "if" there is a "SC014 Campaign" label attached under the hood of 97~99 Sportages and if not forward this SB to those owners...
We see a lot of early Sportages with intermittent "no start" and "dies" in the thread titles... I wonder how many are still out there that this problem hasn't been addressed when they were new to a couple of years old?