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I have a 2000 Kia Sportage with 2.0L engine that I am fixing up to resell. It had a bad ignition coil so I replaced both and also new wires and plugs. It runs good at idle and around town, but on the freeway I can barely get it to the speed limit of 75 mph and when I come to a long incline it drops to 60 mph. With my scan tool, found the MAF sensor was reading too high, from .25 lb/s at idle to .42 lb/s at full throttle. I replaced the MAF and now it reads .01 to under .10 at WOT. (I compared this to another vehicle I own and its MAF reads the same range). I also noticed the Throttle position sensor appeared to read incorrectly, showing 11% open at idle and only going to 83.4% at WOT while driving, so I got one of those too. Now it reads 5.9% at idle and only goes to 81.4% at WOT.

It looks like some work was done to this car before I got it. ONE front caliper and brake pad set was replaced, along with new belts. I opened the timing cover and peeked inside and it appears the timing belt was replaced too so I am wondering if it was installed correctly, perhaps the timing is off? Does anyone have the specs what the timing should be at idle, vs WOT or at a certain RPM range? I can check this with my scan tool and perhaps solve my problem. If the belt was installed one "tooth" off, would the engine still run and if so, how far off would the timing be?
 

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'96 Camry v6 XLE, '00 Camry LE
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I have a 2000 Kia Sportage with 2.0L engine that I am fixing up to resell. It had a bad ignition coil so I replaced both and also new wires and plugs. It runs good at idle and around town, but on the freeway I can barely get it to the speed limit of 75 mph and when I come to a long incline it drops to 60 mph. With my scan tool, found the MAF sensor was reading too high, from .25 lb/s at idle to .42 lb/s at full throttle. I replaced the MAF and now it reads .01 to under .10 at WOT. (I compared this to another vehicle I own and its MAF reads the same range). I also noticed the Throttle position sensor appeared to read incorrectly, showing 11% open at idle and only going to 83.4% at WOT while driving, so I got one of those too. Now it reads 5.9% at idle and only goes to 81.4% at WOT.

It looks like some work was done to this car before I got it. ONE front caliper and brake pad set was replaced, along with new belts. I opened the timing cover and peeked inside and it appears the timing belt was replaced too so I am wondering if it was installed correctly, perhaps the timing is off? Does anyone have the specs what the timing should be at idle, vs WOT or at a certain RPM range? I can check this with my scan tool and perhaps solve my problem. If the belt was installed one "tooth" off, would the engine still run and if so, how far off would the timing be?
The ECU will automatically compensate / and adjust timing, even if physical mechanical timing is off, "up to a point", so trying to verify static mechanical timing using electronics only -will not work-.

You need to physically verify (static) mechanical timing positions on the Cam and Crank gears, to ensure correct alignment. Remove the timing covers, align to #1 TDC, (pull #1 spark plug, insert a thin screwdriver or dowel, and watch piston rise/fall to ensure TDC / doubly verify) and check all marks match up.

Yes, the engine -will run- even if the Intake or Exhaust cams are one "tooth" off - it will not "run well" though.. see above.

Regards, GottaCruise
 

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The ECU will automatically compensate / and adjust timing, even if physical mechanical timing is off, "up to a point", so trying to verify static mechanical timing using electronics only -will not work-.

You need to physically verify (static) mechanical timing positions on the Cam and Crank gears, to ensure correct alignment. Remove the timing covers, align to #1 TDC, (pull #1 spark plug, insert a thin screwdriver or dowel, and watch piston rise/fall to ensure TDC / doubly verify) and check all marks match up.

Yes, the engine -will run- even if the Intake or Exhaust cams are one "tooth" off - it will not "run well" though.. see above.

Regards, GottaCruise
Sounds like I need to check that out next as I have tried everything else. I was wondering though, if it would affect compression. I did a compression test when I first started on this car and had 150# - 160# per cylinder. Judging by the "quality" of work done by the previous owners so-called mechanic, I can easily imagine that the timing belt was not installed correctly.
 

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09 kia spectra ex,04 Neon,04 Chry. T&C, 08 Pontiac G6 gt
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Any CEL codes? This would go a long way in determining what's going on.Also if motor was running so poorly and when before you got your hands on it, it could have a bad cat. converter. They can run fine at idle and flat running...until higher speed loads sand hills.
 

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Any CEL codes? This would go a long way in determining what's going on.Also if motor was running so poorly and when before you got your hands on it, it could have a bad cat. converter. They can run fine at idle and flat running...until higher speed loads sand hills.
I should have added - I gutted the cat thinking that might be the problem. I also checked the operation of the throttle plates to make sure they were opening and closing properly. Since I replaced the MAF there are no codes. I also put a new muffler on, but I don't think that would cause it would it? It is an OEM style with pipe attached, so I know its not on backwards.
 

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Update - when I drive it with my scan tool connected, it will go into Open Loop anytime I exceed about 1/2 the gas pedal travel, such as hard acceleration or climbing a hill. If I "keep my foot in it" it will lose communication link with the scan tool; if I back off, it will go back into Closed Loop until I accelerate again. It runs great around town under light acceleration. Also, the old Throttle position sensor always reads 10% open at idle, and only 82% at wide open throttle. I installed a new one, but it still reads 6% at idle and only 81.4% at WOT. Both tests were done with both the engine running and while driving. I plugged my scan tool into another car I own to verify its accuracy, and the TP on the other car reads 0% at idle and goes to 100% at WOT.

If my scan tool is reading correctly, it appears that the PCM on my Kia is being overloaded with information and/or cannot process the info it is receiving so it defaults into open loop but I want to check everything else before I spend money on a new PCM. Any suggestions?
 

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2011 Forte SX 2.4L (thankfully MPI) A/T 144K miles
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…. I want to check everything else before I spend money on a new PCM. Any suggestions?
Computer is always last on my list of possible suspects, and your case would IMO be a complete waste of $$. On most of my family's vehicles, the idling TPS reading is somewhere around 10%, so I highly doubt the readings your seeing is the issue with yours. Also, I've watched vehicles switch back and forth between OL and CL on the OBD datastream, so that doesn't sound abnormal either.

Two things that come to mind that you haven't mentioned are the upstream O2 sensor and the fuel system. A 'slow' upstream O2 might account for the symptoms you're seeing, but unfortunately it takes a scope to positively diagnose that. Although I don't normally hang parts, some folks replace them as routine maintenance, and perhaps you might consider trying that (instead of paying a shop to diagnose with a scope).

The other possibility is something not being up to par with the fuel system. Injectors would be the first suspect, with fuel pump/filter in the race as well. Fortunately you can DIY all of the testing on fuel system. Perhaps just put a bottle of Techron through it first to see if there's any improvement from doing that.
 

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'96 Camry v6 XLE, '00 Camry LE
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Check to make sure the viscous radiator fan clutch is not 'locked', causing you to lose coolant temp (ECT temp), in conjunction w/ a lazy or partially stuck open thermostat.

Monitoring ECT temp while driving after bring up to operating (closed loop) temp., any major drop in temp - suspect thermostat issue.
 

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Discussion Starter #9
Computer is always last on my list of possible suspects, and your case would IMO be a complete waste of $$. On most of my family's vehicles, the idling TPS reading is somewhere around 10%, so I highly doubt the readings your seeing is the issue with yours. Also, I've watched vehicles switch back and forth between OL and CL on the OBD datastream, so that doesn't sound abnormal either.

Two things that come to mind that you haven't mentioned are the upstream O2 sensor and the fuel system. A 'slow' upstream O2 might account for the symptoms you're seeing, but unfortunately it takes a scope to positively diagnose that. Although I don't normally hang parts, some folks replace them as routine maintenance, and perhaps you might consider trying that (instead of paying a shop to diagnose with a scope).

The other possibility is something not being up to par with the fuel system. Injectors would be the first suspect, with fuel pump/filter in the race as well. Fortunately you can DIY all of the testing on fuel system. Perhaps just put a bottle of Techron through it first to see if there's any improvement from doing that.
I hadn't thought about the O2 sensor, since it didn't throw a code but I will look at that next. When I first bought this car, I went through and did basic maintenance including new plugs and fuel filter. I also ended up replacing the two fuel lines that connect to the filter as the old ones were so brittle they snapped when I tried to remove them. I used genuine Kia lines, but the filter is an aftermarket item. I also replaced both ignition coils and the two plug wires as one of the coils was burnt. The last thing I checked was the timing belt as it appeared to have been replaced recently. The marks lined up properly but it was loose across the top of the cam gears, so I tightened up the adjustment. I had also replaced the muffler, so I even tried putting the old one back on after I gutted the cat.

I bought this car from my brother and the funny thing is that in the sad condition it was in, he drove it 1700 miles when he moved here from Minnesota and said he had no problems running 80 mph on the freeway. I bought it a few weeks after he moved and now after replacing all the parts, I can't get it over 65 when climbing a hill. I also replaced the MAF as it was reading extremely high air flow rate and setting a code. Thanks for the advice.
 
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