Multiple misfires

Tiny
GFSPECTRA
  • MEMBER
  • 2003 KIA SPECTRA
  • 4 CYL
  • FWD
  • MANUAL
  • 54,000 MILES
I have misfires on cylinder 1, 2 and 3. DTC codes P0300, P0301, P0302, P0303. I have replaced plugs (properly gapped), wires, coil packs, fuel filter, fuel injectors. No effect.

Noid light shows pulse signal at fuel injectors. Compression check shows 140 on cyl #1, 150 on cyl #2-4

Thanks for your help!
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Wednesday, April 15th, 2009 AT 1:37 PM

10 Replies

Tiny
JAMES W.
  • MECHANIC
  • 2,395 POSTS
What is the fuel pressure reading? And, can you describe how it's driving going down the road? Please advise.
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Wednesday, April 15th, 2009 AT 5:05 PM
Tiny
GFSPECTRA
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  • 5 POSTS
Bought a gauge to check fuel pressure, but the reading was erratic and fuel accumulated inside the gauge. I assume the gauge was faulty, so I don't have an accurate pressure reading right now.

When cold, the car will start but then die immediately. If I press the gas, I can keep it running, and then it will idle (very rough) once it warms up for about a minute.

When I try to drive it, it stumbles up to about 2500 rpm. Above 2500 it seems smoother and accelerates decently.
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Wednesday, April 15th, 2009 AT 5:25 PM
Tiny
JAMES W.
  • MECHANIC
  • 2,395 POSTS
Well, if it were a fuel pressure problem, the symptoms would be the other way around. Good performance at low revs and poor at higher revs under load.
I'm assuming you have not had a "check engine light". A problem with the cam sensor will usually trip the CEL, but many times a bad throttle position sensor won't. I'll see if I can find the TPS test specs and attach them to this post. I now sounds like the TPS may have a dead spot in it.


https://www.2carpros.com/forum/automotive_pictures/248092_03_Kia_1.jpg



https://www.2carpros.com/forum/automotive_pictures/248092_03_Kia_1_1.jpg



https://www.2carpros.com/forum/automotive_pictures/248092_03_Kia_2_1.jpg

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Wednesday, April 15th, 2009 AT 6:17 PM
Tiny
GFSPECTRA
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  • 5 POSTS
I do have CEL, codes P0300, P0301, P0302, P0303. Just misfire codes. Would a bad TPS cause misfires like that? Thanks for the spec sheet, I'll test the TPS as soon as I get some daylight.
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Wednesday, April 15th, 2009 AT 7:58 PM
Tiny
JAMES W.
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The term "miltiple missfires" mean that a given cylinder is not firing. This isn't just limited to spark. A lean condition can also cause a misfire. And, a possible cause of this could be the TPS. Let me know what you find.
AND, what do you mean, "get some daylight", it's still daylight here. Pardon my twisted humor.
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Wednesday, April 15th, 2009 AT 8:14 PM
Tiny
GFSPECTRA
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  • 5 POSTS
Sounds good, I'll check it out. My work schedule doesn't allow me much daylight :)

I'll post my findings.
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Thursday, April 16th, 2009 AT 9:57 AM
Tiny
GFSPECTRA
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Ok, TPS was slightly off the numbers you posted. I replaced it and cleared DTC codes. Started it up and it ran (didn't stall immediately like usual), but still very rough. After a couple minutes the misfire codes came back (cyl 1 & 3)

Side note, I can hear what sounds like sparks arcing to the block intermittently. It will do it for 30 seconds, then stop for a minute, etc. I started the car in the dark and couldn't see any arcing.
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Wednesday, April 22nd, 2009 AT 10:19 AM
Tiny
KINGROCK
  • MEMBER
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Did you ever find the problem? I'm having a misfire on my car and figured your solution may help me if you could just post the result.

Thanks!
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Tuesday, August 11th, 2009 AT 4:36 PM
Tiny
MATT BEAUCHAMP
  • MEMBER
  • 1 POST
Working on my parents 03 kia spectra that has same misfire issues. The more I messed with it the more random the misfires became, especially on cylinders 1 and 3. Started looking at the coil pack harness connector and noticed one wire wasn't pushed in as much as the other wire. Come to find oit the connector has deteriorated and is falling apart. Hoping that will fix my misfires
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Monday, February 18th, 2019 AT 7:07 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 42,554 POSTS
Yep it sounds like it will. here is a guide that can help. I have seen a bad MAF sensor cause this issue as well, check out the diagrams below.

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

and

https://www.2carpros.com/articles/how-to-replace-a-mass-air-flow-sensor-maf

Check out the diagrams (below). Please let us know what happens.
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Monday, February 18th, 2019 AT 10:04 AM

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