the 2005 kia amanti is misfiring does not accelerate properly , where should i began to troubleshoot

if the engin light is on start there. some parts stores will scan it for free.

diagnostic was done twice ,the first report stated probable causes catalyst efficiency low bank 2,the oxygen sensors monitor the catalyst converter ability to store oxygen,engine misfire,large vacuum leak, engine oil leakage into exhaust valve guide, seals piston rings.

mechanic recommended a complete tune-up the car still wasn't performing properly.took it to the kia dealer and they did a diagnostic and stated that the car needed a tune-up and flush throttle body

is the engin light on now, if so do you know the new codes? has a compression test been preformed? if your getting a cat. preformance code, that tells me the misfire is has left over fuel during misfire.

2005 Kia amanti. For the past 3 months my car has been losing power and had gotten worse. Here is what I did so far and nothing has fixed the problem. replaced 2 o2 sensors, wires, plugs, coils, throttle body, fuel injector, front catalytic converter still getting engine 3 misfire code car loses power. Checked timing belt and that is fine

have you check the compression yet?

yes the compression is fine

how about the wiring from coil to ecm?
just what codes are setting?

My "Colleagues" have given you some excellent "Repair" and "Troubleshooting" advice.

IT'S TIME TO TAKE YOUR ISSUE TO THE NEXT LEVEL !!!!

THAT'S WERE YOU COME IN !!!!

Post the "Actual" error "Code Numbers" so we can help you further.

p0303 engine 3 misfire. didn't change any other wires except for plugs. Fixed Cat today and gained more power since the clog is gone but I'm sure you know it will get ruined again if I don't fix misfire. Was getting a code for o2 sensor and cat then I fixed o2 sensor and it went away. a few days later light came back on with the same code. changed a different o2 sensor but didn't get power back. code went away then came back with P0303. changed throttle body, plugs and wires no improvement. took it to Kia dealership they ran diagnostics and said coils were bad. replaced coils no improvement. Took it to another garage to see if the cat was clogged. they said fuel injector was bad which I replaced along with 4 gaskets. no fix same code. they checked timing belt said it was fine even though it has 125,000. finally they found a clogged cat which they replaced I have not drove it yet but they said it got back a lot of power but still misfire. 4 different garages no fix yet.

Thanks for your last post. Do the following and post the results.

Use a "Noid light" to confirm that the "Third" fuel injector is firing.

"Swap" the "Number 3" ignition cable with "Any" other ignition cable. Does the "Misfire" follow to the "Swaped" cable?

"Replace" the "Number 3" spark plug.

i'd do a running compression test on it, you may have a valve not opening all the way, witch would pass a stagnet test.
some times it's just a carbon build up on the valves.
chrysler has a lot of problems with carbon setting misfire codes.

thank you. at this time the garage is closed, but I will call them in the morning with your suggestions. here is what I know about your comments. I replaced the number three plug (and the other 5) and injector. i disconnected each of the three front coils and the engine did lose power while idling. which tells me the coils and plugs are working since I did it one at a time. I'm not sure if the car was running or stagnet, but I was told that I had 150 compression if I remember correctly. I read on another thread that maybe the crank and cam shaft sensors could be bad? here is a link to that http://www.fixya.com/cars/t6878775-05_kia_amanti_diagnostics. i'm in to well over a $1000.00 in total repairs since most of the work was done by my friend who runs a garage around me, and nobody seems to know where to go next.

i'd say stop replacing things, way too many already.
if your chasing a p0303, stick to it.
a misfire is just fuel that didn't get burned correctly, so lets stay with the combustion chamber for now.

Just a reminder, and you can mention this to your mechanic as well.

“Vacuum Leaks Cause Misfires”. So doing an “Engine Vacuum Pressure Test” could reveal something.

Not for nothing, but just make sure the “Firing Order” is correct.

Also and just for the sake of “Curiosity”, if “swapping” ignition cables makes no difference, then try “Swapping Coils” to see if the misfire “follows”.

The list below may be off the “Top of my head”, but its “Short and Sweet” and to the “Point”. Basically speaking, anything below could be causing your “Misfire”.

Spark plug or ignition cable issues

Ignition wiring, circuit, or connection issues

Ground wire issues

Coil pack issues

ERG issues

Issues with one or more oxygen sensors

Fuel injector issues

Burned, stuck, or defective exhaust valve

Issues with one or more defective catalytic converters

Issues with fuel pressure and volume

Cylinder compression issues

Defective computer, or the need for a “Re-Flash”.

Good Luck and keep in touch
Sam

Talked to garage they said they can't do a running compression test because they have to take the header off to get to the back 3 valves. They are doing the vacuum test now. they don't have the equipment to re-flash the engine. Car doesn't misfire in the idle position only when accelerating. problem is worse when the car tries going up a hill. also we swapped coils and plugs and the misfire continued.

did the misfire stay in #3after swapping?

yes

try having a carbon clean done.
you can pick up a kit and do it yourself.

List everything that has been "Positively" ruled out to "This Point".

garage says carbon clean usually fixes idling problems and better gas millage. he said he will do it for the cost of the chemicals which is $20-$25 but he doesn't think it will work. They just called and said they give up and can't fix the problem. Could it be the computer? He thinks doing a running compression would be great but can't do it. Firing order is correct and doing test came out good when they did a Vacuum Leaks.

there is a flash for the computer, but it's not that that code, i'll post it and let me know what you think.
it says it for better driveability improvement, it may or may not help, here's what it says:

Engine Controls - ECU Update for Driveability Issues

Model Amanti [GH]

Group: Fuel System(14)

Number: KT2007030801

Date: Thursday, March 08, 2007

Area: N. America

Subject
ECU Upgrade - Driveability Improvement (Engine - 029)
(Updated 2007-03-12)

- Description

This service bulletin provides information regarding an ECU upgrade for Powertrain Control Modules (PCMs) of 2005-2006 Amanti vehicles. This upgrade will improve driveability while accelerating during cold engine
operation or after starting the engine.

I’m not the type to bash another individuals efforts or another mechanic.

Based on your last posting, it’s clear to me that you need to find another mechanic.

When you do have him (or her) have that individual retrieve the “Live Data”, then “Post” the data for us see.

If the individual has “Solid Skills” the term “Live Data” shouldn’t be a problem.

In the “Mean Time” you can do the following yourself:

“Clear” the code and then simply the car. Let us know if PO303 “Sets Again”, along with “Any Other” codes that “May Set”.

Ok, so you “Swapped” the number 3 coil and plug with others and it made no difference,

WELL !!!!

Now I want you to “Swap” the number 3,

“FUEL INJECTOR” with “ANOTHER INJECTOR” and post the results.

I will have to take the car to Kia to flash the computer correct? I have cleared the code several times and so has the current mechanic and the same p0303 keeps coming back. that is the only code I have received in several weeks. I had them swap the number 3 fuel injector with a brand new part I bought from NAPA. That was their first suggestion, and didn't fix the problem. I have taken the car to 4 different mechanics and here is what happened. driving on a long trip from PA to SC and when I hit VA I noticed my car came out of cruise control and began to lose speed. It felt like the transmission was slipping I had no top end speed. I took the car and got a free diagnostics done which said bad o2 sensor or cat. Took it to a local mechanic and he replaced the O2 sensor in the front middle of the engine block closest to the fan belt. Car ran fine for another day or two and then on my way to GA same thing happened with the loss of power. got another free diagnostics done same codes as before o2 sensor and cat. Drove the car home took the car to my friend who is a mechanic and works on all my cars and he ran diagnostics and replaced a second 02 sensor and that didn't fix the problem. Ran diagnostics again which said P0303 no longer anything about the o2 sensor or cat. I continued to drive the car and the problem got progressively worse losing more and more power. He suggested we change the throttle body, plugs, and wires which we did. cleared the codes car ran the same and same code appeared. Took the car to a Kia dealership they ran diagnostics and said p0303 and something about a bad #3 coil which I may have broke when I was replacing the plugs. I put new coils on cleared codes car ran the same P0303 came back. took the car to a fourth shop because they specialize in cat problems which my friend seemed to think was clogged. from there everything else is listed above. You are very helpful with your suggestions which I have been relaying to my mechanics and friend, but I don't know what else to do besides send the computer out for repair if it is broken.

it's hard for me to say with out checking it myself, i'm still not sure if it's mechanical or eletrical, but belive that it can be narrowed down to the cause with out replacing any more parts.
as far as that flash goes, it's not to fix a misfire in one cylinder, just over all improvement of performance, mostly in cold weather.
did the dealer diag. and replace the coil?

yes the dealer diagnosed the coil problem. I fixed it myself and I have confirmed that it is correct and working.

What’s the mileage on the car?

It “Sounds” like when the “Engine” is under a “LOAD” the “Timing Belt” is “Slipping” causing the engine to “Jump Time”. If that’s the case, that would “Definitely” cause a “Misfire”. This is especially “Problematic”, because the “Engine” in your “Amanti” is the “Interference” type. If you don’t know what “Interference” means, let us know and we’ll explain it to you.

Has the timing belt been changed recently?

If not, is it due for a change?

The “Timing Belt” covers should be removed, so that the “Belt” can be “Physically” evaluated, by a professional for “Wear and Tension”.

Has the fuel filter been changed recently?

Using a “FUEL PRESSURE GAUGE” confirm the “FUEL PSI” values below.

At an “Idle” and at normal “Operating Temperature”, and with the vacuum hose:

“CONNECTED TO THE FUEL PRESSURE REGULATOR” (Fuel PSI should be 46 to 49 PSI).

ALSO:

“Fuel PSI” should be (39 PSI) with the vacuum hose (“DISCONNECTED”) from the fuel pressure regulator.

What’s the mileage on the car? 125,000

It “Sounds” like when the “Engine” is under a “LOAD” the “Timing Belt” is “Slipping” causing the engine to “Jump Time”. - they checked the timing belt and it is not slipping.

Has the fuel filter been changed recently? no it has not to my knowledge

They did a vacuum test today and it came back normal.

Thanks for your last posting. I read the part were you stated; "The vacuum test came back normal".

In my posting, where I mention "Fuel PSI", I'm referring to a "Fuel Pressure Test" that is done with a "Fuel Pressure Gauge".

This is a "COMPLETELY DIFFERENT" test from the "Vacuum Test" that was done.

The "Fuel Pressure Test" is necessary, because "Issues" with "Fuel Pressure and Volume"

"CAN CAUSE MISFIRES".

With 125.000 miles if the fuel filter "HASN'T" been changed ????

IT SHOULD BE !!!!

Keep In Touch
Good Luck
Sam
fvacuumom complete

did they test the coolant temp sensor? If you want to have it done, check the price they charge and compare it to the price of a new sensor. If sensor is cheaper, just replace it.

coolant sensor would effect all cylinders not just #3, they need to take it some where that will stand behind thier diag. and repair.

I have the same problem. It was like water in the gas tank or something. Originally it only happened accelerating around 50mph and didn't matter if I came up a entry ramp on a highway or hill. I could step on the gas & it would buck, but eventually take off like a rocket. A hill was the worst though, I will admit. I have 95k miles on mine. Now, after months of this problem, mine will shutter and shake sitting at a stop light sometimes. I'm a cheapscape & was scared of the same expensive(lets try this) approach your mechanic is pulling on you. The timing belt thing crossed my mind, but after trying out some fuel cleaners I think it is fuel related only. Most fuel cleaners, and I must have tried 7 different brands over the months, made no difference whatsoever. But, if I used Gumout High Mileage Fuel System Cleaner then the change was dramatic. The regular gumout didn't do anything. Just the high mileage version works. Don't ask me why - No idea.
So, even though Kia says the Fuel Filter is a lifetime part, I say bull crap. Get some bad gas & it will clog. I think the ethanol does it. I'm getting a fuel filter this week & try it out. Only $18 and some time to change it. After that - I'll be scared of what it might be & how much it will cost, again.

let us know the out come.

good idea.

you could also swap the #3 ignition coil with another cylinder and drive the car for a while and have the computer scanned again. if the misfire is now on the cylider which recieved the #3 coil; then the coil is bad.