2000 Sephia Rough Idle, Engine light on, no error code?

[TxDriver]

Hi,

First I am new to the forums, glad you have them!

I have a 2000 Kia Sephia, with 99,xxx miles on it. Really not many issues, mostly plug wires and coils.

Then one day, about 10 miles after stopping to get a 12gal fill-up the car starting idling rough, loss of acceleration and the check engine light came on. The RPMs "seem" to stay at a constant x750 RPM, but the the Engine is rough, really rough. maybe knocks too, but I cannot tell. It may be my car rattling :-)

Now, I do not think it is a bad tank of gas, but that is one possibility. I am not sure how a bad tank of gas would cause the these issues...especially the check engine

The problem happened in Houston. So I went to Auto zone and Advanced Auto parts to get the code read, but neither place could retrieve a code. They said the reader was connected, but there was not an error code.

So I live in Austin, and wanted to get back home. The problem happened 5PM on Sunday not many places open...so I decided to make the 160 mile hike back home.

Made it back ok, with the check engine light on( I know, not the smarted thing). I then had the code checked at a local Austin store, and no luck.

I am clueless as to what the problem is.

No error code when connecting the obd-II reader.

According to BAT Auto Technical-Professional mechanics giving advice-An Educational Site w/ OBD2 Trouble Codes and Technical info & Tool Store.

"Trouble Code Interpretation

The ECM indicates stored fault code by flashing the malfunction indicator/check engine lamp. Fault codes 1 through 9 are indicated by individual short blinks and fault codes 10 and above are indicated by long and short blinks. One long blink is equivalent to 10 short blinks. The fault code can be determined by adding the long and short blinks."
of course my engine light does blink, but I am not sure what is a "long" blink. Any ideas?


I had an rough idle issue before, but that was a #3 misfire and plug wires took care of the issue.

Now, I looked at one of my coil packs and one of them seem discolored. One is the normal light khaki color, but the other is a darker khaki color. I am not sure if this is the issue, but I really do not wanna spend $60 on a coil if that is not the problem. Plug wires are about 30k old

Anyone have any suggestion?

Ever see an engine light on with rough idling/knocking, loss of acceleration and not giving error codes?

Ideas?

thanks

[ron1004]

Cant understand why the codes cant be read.

The codes can be read by connecting a jumper on the Diagnostics Test Plug then counting the number of short and long pulses of the CEL light with the ignition sitch turned on.
http://www.kia-forums.com/do-yoursel...ble-codes.html

Your problem could be a bad O2 sensor, and when this happens the ECU uses a 'limp home' value in place of the O2 sensor signal, and this results in a rich mixture , sluggish, and rough idle.

[TxDriver]

Ok, so how much are oxygen sensors?

I see them ranging from $20 to $100?

Site has a

#USOS-1000 Oxygen Sensor Replacement $28.38

Vehicle:
1995 – 2001 Kia Sephia

Fits Engine – Chassis:
1.8L, 4 Cylinder — Sephia

Description:
OXYGEN SENSOR -- Oxygen Sensor. Univeral Type, 1 Wire 20cm Long, w/o Connectors, Ground Shipping Only

and there are some that are 4x that price?

AutoZone appears to be selling them for $85 plus? what is the difference? Also, there appears to be an oxygen sensor for before the cat and after the cat?

PartsTrain.com - Hard to Find Auto Parts and Truck Parts
has them from $20 on up?

thanks

[1fastkia]

Im gonna go out on a limb and say plug wires are bad. An oxygen sensor usually throws a cel but not a blinking cel...

[TxDriver]

1fastkia,

I think you were right,

I change the plug wires and spark plugs and problem was solved. $30...not bad.

I am not sure which one it was, but figured while I am change plug wires, what is an extra 5 minutes to change plugs ...

I noticed that the one plug was pretty messed up. It was all fouled up and looked like it has some oil on it ...

I looked around the gasket and notice I could get some oil on a rag in the "spark" plug cylinder area( at the top of the cylinder, not bottom) ..not sure what the real name for it is. So i think when i have time i will replace that gasket.

anyone have a engine diagram so i know what the name of the gasket is?

thanks

[1fastkia]

the valve cover gasket

[TxDriver]

thanks man!