misfire no power?

Hello, and thanks for your question!

If you had O2 sensor codes, there is a possibility there was a problem with the exhaust system and not the sensors themselves. Sure, the new sensors will function better brand new, but it most cases it only buys time. Do you by chance have the codes that were present, or can you do a scan of the vehicle now?

Please check out this link on how to perform a CAN scan:
https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Being a 2021 model, I would not be so concerned about clogged fuel lines or fuel pump assembly. Actually, the fact that it will not go above 2,000 rpm is the computer putting a limit on the system. Despite doing all of those things that you did; the computer still detects a problem somewhere.

Please let me know what you find,
William

Got a P0340 code after changing back sparkplugs. Driving 3 hours round trip to a dealer to get a camshaft position sensor, got it back to install and discovered I didn't plug the sensor back in. Embarrassing! Here are the codes I wrote down. I will go out today and get which are pending, permanent etc.
P0088
P0306
P0305
P0300
P0304
hopefully this will give a pattern
again, starts and idles. start driving and it misfires, can't get it above 2,000 RPMs. goes in reverse well. :-)

I can't tell you how much I appreciate you communicating with me. If you are in the East TN area let me know. I own a pub/restaurant on the Appalachian trail and have airbnb's.

I sprayed starter fluid around to check for vacuum leaks, none.

Okay, one current code today. check engine light came back on. P0088

Hello,

P0088 = Fuel Rail / System Pressure Too High

This of course can throw off fuel trim / air ratio and ruin O2 sensors, as well as cause misfires and result in the computer limiting the engine performance. I will attach the chart below on the plausible causes for this. Does your scan tool see live data? I would like to know the actual fuel rail pressure as reported by the sensor, as well as the ECT (Engine Coolant Temperature) sensor, and the exact RPM the engine is running at idle. We can try to pinpoint the issue to see if it is a sensor issue or a regulatory issue, and worst-case scenario being an ECM issue.

Hope this helps and let me know what you find.
William

screen shots live. idles well.

have a video of it running idle and pressing gas but too big to load and send.

Not good if you are stumped.

Did lose you William? More than happy to compensate you to finish this thread.

Hello,

Sorry for the delay. Using that scan tool, can you see the live fuel pressure reading? And when the engine is at operating temp, what does the ECT read? Please refer to the chart above, and make sure the conditions are met. We need to get past this before we dive into electrical diagnostics or replacing parts.

Thanks,
William

Bummer, I thought I screen shot it all. I will do it fitting tomorrow.

Real quick what is ECT?

Electronically Controlled Transmission?

ECT reads 30 degrees C. Do I need to let the car warm up more?

fuel level input 48.2%.

the rest I will check tomorrow.

Hi,

I would like to know what the ECT reads during normal vehicle operation, when the temperature gauge settles in the middle. It should not be more than 60 C. Fuel level input is only a display of how much fuel is in the tank. We need to see the fuel pressure in PSI. If we cannot see this then we will need to take a fuel pressure reading with a gauge at the fuel rail.

Let me know,
William

Okay, new data, new codes. outside temp 37 degrees. Warmed van up so the temperature gauge was 1/2 way. Idle was great. press gas no hesitation or skip. backed up smooth, put in gear and pressed gas no power. After trying to drive the traction control light came on the dash, pressed button and it wouldn't go off.

60 degrees Celsius is only 140 degree Fahrenheit btw. So, the ECT (engine coolant temperature sensor) could be off, but I see from the scanner it is at 94% which is good. I have seen a broken primary catalytic converter cause strange issues like this. Can you hear any kind of rattle in the exhaust when the engine is idling/revving? You might want to take a rubber mallet and tap the exhaust to see if you can hear any loose material inside. Here is how to remove the cats for a physical inspection. Check out the images (below). Please upload pictures or videos of the problem so we can see what's going on.

I changed the O2 sensor on the front exhaust already. Took it off and ran engine as well to check catalytic converter. Fact that it idles great but won't go when press gas is leading to fuel pressure control valve or pressure sensor on rail. Wish I knew which one before spending the big money.

So, no sense in changing out the ECT since you think 94% and it's good? I will go under and tap the converter as well. Which two O2 sensors do I take off and run engine? I think I heard you do something like that to test the catalytic converter.

we might be barking up the wrong tree, the P0088 code "Fuel Rail/System Pressure - Too High." Which means the high pressure pump pressure regulator has gone bad or the sensor is bad, lets try replacing the sensor and if that doesn't help the high pressure pump will need to be replaced. Here are the instructions to help us fix the problem. Check out the images (below). Please let us know what happens.

If you have a part number handy it would save me a ton of time. If not, no big deal. I'm extremely grateful for your help!!!

So, from what I see it's called the rail pressure sensor.

looks like I'll be down near the injectors. Do anything to them, clean?

yup, not a clue which part I'm looking for. Sorry for being such a rookie.

I'm pretty sure this is it https://www.amazon.com/Injection-Pressure-2006-2022-Compatible-0281002863/dp/B0CHFXBYNR

Kia 353422E610

Here is what the sensor looks like which is the one you found on Amazon. I would change that out and if that does not fix it, I would change out the high-pressure fuel pump.

I have that part arriving tomorrow. I've been searching for two hours for a video or diagram that makes sense of where this thing is located. I know it's on the fuel rail, but there are no videos showing how to do it. Not sure what to remove. I even tried to get a video on how to get to injectors which would get me to the rail.

Hello,

Sorry for the delay, I've been a little under the weather. I see you want to tackle the fuel rail pressure sensor (RPS). I will write the instructions below, the intake manifold will need to come off.

1. Release fuel line pressure.
(I like to pull the fuel pump relay and crank the engine over a couple of times)
2. Remove the engine cover.
3. Remove the air cleaner assembly.
4. Remove the surge tank.
5. Remove the low pressure fuel line.
- careful, there still may be residual pressure here when you crack the nut, put a towel over is as you turn-
6. Remove the intake manifold (A).
(See image 1)

-Note, try to protect the intake ports with the manifold off, as engine coolant may run into them, causing some issues when starting-

Now you should be able to see the fuel rail pressure sensor (See image 2). It should have a nut on it and be fairly straight-forward at this point.

Installation is the reverse of removal, torque for the intake manifold is below, and order of tightening is in image 3.

Tightening torque
Step 1 (a - h) : 3.9 - 5.9 N·m (0.4 - 0.6 kgf·m, 2.9 - 4.3 lb·ft)
Step 2 (1 - 8) : 26.5 - 31.4 N·m (2.7 - 3.2 kgf·m, 19.5 - 23.1 lb·ft)
Step 3 : Repeat 2nd step twice or more.

Let me know how it goes,
William

Awesome! Thanks so much. I hope you feel better and I will give you an update tomorrow night.

Thanks, I'm looking forward to some good news!

-William

pulled it all apart, replaced the sensor on the rail, put it all together, started it and gas was gushing from the bottom of the engine. nothing coming out of the top. Taking a quick time out and then going back to tear it all apart again and try to find where the leak is coming from. Maybe I didn't tighten the sensor enough, not sure.

Hello,

Oof, that's not good. Make sure the o-ring is seated well on the sensor and compare it to the old sensor. Before starting, let the car prime fuel pressure and check for leaks during that time before you decide to send the fire.

Let me know,
William

That wasn't it. Had more help from my neighbor who is an old school mechanic and his friend stopped by. They discovered the new ignition coil I bought wasn't working and they decided to do a compression test. Both said it is the injectors. So I will change them out.

Hello,

I'm sorry, but I don't follow what you're saying. Certainly, a bad coil can cause issues, but not about leaking gas. Most definitely a bad injector can leak gas, but a compression test would not lead one to believe an injector is bad.

Likewise, a fuel leak would not cause the code P0088 you were having about high fuel pressure. However, I could see too high of pressure cause an injector to leak, and at that point I would replace the high-pressure pump.

Could you give us some more insight on the problem?

Thanks,
William

The fuel leak was my fault. I didn't tighten the fuel injection sensor enough. It was loose and that's where the gas was coming from. Put it back together again and still same issue. The boys did a compression test and told me it is most likely injectors, but after reading your post it probably isn't. I've ordered injectors to arrive Wednesday. I guess I should put it back on the tester and see what codes I get. I am hoping that the dealership will have an ignition coil in stock so I don't have to wait for shipping. I wish I knew for sure injectors or pump. can't really afford both. Wanted to take this van to Florida end of the month. Hope you are enjoying some Christmas time off and thank you for keeping up with me!

Hello,

No problem! If the fuel injectors are not leaking, I wouldn't replace them without knowing they are clogged. You can take them out and clean them if you want. A compression test will not tell you anything about injectors considering you are required to cut fuel supply to do the compression test, for safety reasons and because you only need the car to crank.

If you can use your scan tool and read the fuel pressure readings (should be kpa, bar, or psi units), it may lead us in the right direction. The scan tool should also be able to tell the voltage received by the sensor. If the pressure is too high at the rail, then it will need a high-pressure fuel pump. If it looks normal, then we need to start doing some electrical diagnostics.

Have a great holiday!
William