20 Most Recent 1999 Kia Sephia - Page 8 Questions & Answers

PO121 : TP Sensor Performance = The PCM supplies 5V to the TP sensor(throttle position). The TP sensor is a variable resistor that drops the voltage to about 4 volts at WOT(wide open throttle) to less than 1 volt at closed throttle. Some TP sensors are adjustable. others have a learn procedure to determine closed throttle. PO171 Fuel Trim System Lean = In closed loop the PCM adjusts fuel delivery based on H2OS 1 readings and is indicated by long & short fuel trim values. If lean the PCM will add fuel (fuel trim above 0%) & if rich the PCM will reduce fuel(fuel trim below 0%) PO128 ECT Below Thermostat Regulating Temperature = possible failed thermostat, low or empty on coolant, Engine Coolant Temp Sensor, Poor connection/Harness/Wires, faulty PCM Connection. I think you hit the nail on the head , the ECT Sensor ( which is different than the temp sensor for the dash gauge)

Thanks for choosing FixYa and welcome.

no they auto ajust as they were if your clutch is slipping you going to need to replace it i would also
recommend replacing the pilot bearing throwout bearing and pressure plate while your in there not to hard to do


if i have help would you mind leaving positive feedback thanks

well first check transmitton fluid when the trans is at normal operating temps if that is normal
look at the color of the fluid it should be bright reddish color then if it is brownish or any other color than bright reddish or smells burnt you have an internal trans problem.

now if the color is reddish and does not smell burn there are numerous other things that can cause that such as clogged trans filter , shift linkage is loose or needs ajustment , or faulty shift sensors ,
or trans speed sensor that tells when to shift

Can you post which two your referring to?

Get the cooling system pressure tested to pin point the problem.Check color of oil and traces of water from exhaust or on spark plugs to eliminate a failed head gaskit (and should be fixed if still under warrenty)

perhaps the engine is seized ?? so it will not turn over ,or the battery was duff one when bought it ,i have had three duff batteries from the auto factor in teh last month or so

check the fuel filter it may be dirty. and not letting enough fuel threw under engine load.

if you put shifter in nuetral and you start car and release clutch does it go? If yes then there is a trans or linkage problem. If you can shift car and the clutch disengages yet car wont roll i would check the brakes for broken hardware or frozen calipers.

This can be caused by plugged PCV Valve, Or plugged oil passage return ports in the head.

you have to get the computer scanned and see what code is being stored, this will tell you what area to diagnose.

check both fuses? one in car one under hood called a fuel relay. good luck.

Unless there is some sort of a block from getting stuff shipped in from the US, Why don't you click here Autozone and see if they will ship you one over. Not sure how it works but I would think they would do it. This is just a suggestion and I hope this helps. good luck

Take Kia to Auto Zone, thay offer free diagnosing on check engine lights

check with code scanner for fault code/bring to garage to scan

It should be located under the hood, center, rear engine area, mounted on upper firewall. I hope this helps and good luck.

All fuel pressure regulators located on the fuel rail.

The idle is not adjustable. It is computer controlled..

reach under the front wheel and tap on the starter with a small metal something... see if the starter is the problem that way.