Remove the B1S1 O2 and install a low pressure gauge, >2psi @2000rpm N/S.

If that checks OK, revisit MAF, best to check the ST/LT fuel trims and compare with B1S1

Report back

... Philip

 

Thanks for the response. I assume by installing a pressure gauge in the 02 port you are checking for exhaust restrictions. I currently haven't put the exhaust back on the car other than the new exhaust manifold and new converter which bolts directly to it. I've been pulling parts off of a wrecked 2000 sportage. The one thing I haven't swapped out is the MAF, although I unplugged it and took it down the road and had no change in performance. When I get back to the wrecked sportage Thursday, I will pull the MAF and swap it with mine. To add some history, I did get a tank full of bad gas in the car about 6 or 8 months ago. Had about 3 gallons of water in the tank. I pumped and cleaned the tank out and changed filter, and after a couple days it finally quit sputtering and has ran fine until now. This thing just won't rev. In park at WOT in only hits about 4500.

 

.... I did a compression test and was 140, 128, 130, 128. ....

I'm not familiar with this vehicle, but generically even 140 sounds low to me. However, I certainly could be wrong about that. Do you have the compression range specified by Kia? If not, perhaps someone else knows what it is. In any case, the high/low differential is pushing the generally acceptable 15%, so that's a bit of a red flag. Did the values change wet versus dry? (assuming that you did that extra test).

 

PSI is PSI regardless of gauge brand.. I too believe the compression is low, would expect ~180psi...

Low comp across the board points to poor cylinder/valve timing, or general poor engine health..

I would do a cylinder leak test...

... Philip

 

I'm going to redo the compression test. Was raining and I was working on it outside and was rushing. I don't have the long metal tube adapter to get all the way down through the valve cover to the plug holes, so i was trying to turn the rubber line to tighten it up enough to get it to seal. I had to make several attempts on some cylinders before I got readings above 50 psi. Also not sure I let the motor turn over 5 times on each cylinder. I'm hoping for better results this time. With the fuel problems I had in the past, I'm going to pull the fuel rail and test, clean the injectors while I can get to them also. This thing has 170K on it, but its in better condition than most of these that I've seen, and it's been a really dependable little SUV right up until this started. I'm sure a lot of people wouldn't put much effort into a Kia this old with this many miles, but I like this little ride and I'm not going to give up on it yet. I hope to get all this done as well as get the other MAF put on Thursday. Will post results, and once again, Thanks.

 

Just a hunch, but did you check the air inlet & tubing from the radiator to the air filter? I had some acorns in there one time, in went the mothballs!

 

I had the underhood insulation block the intake and car wouldn't go faster than 45mph. Trimed the insulation and fixed the problem.

 

Update. Bought a new compression tester. Results with cold engine dry test. 176. 60, 175, 172. I made several tests on number 2 cylinder. First test was 110-115. Then 3 consistent of around 60 psi. So now to find out where its going. I don't have a leak down tester, So this will be a good excuse to buy one.

 

On the bad cyl, test it again with a squirt of oil. If it doesn't change much, I'd check the valve stem seals and valves. If it drastically improves after several attempts, could be a piston ring.