S60 Sputtering on acceleration?

wooshybum · Post by **wooshybum** » 28 Mar 2018, 05:33

Hey guys, I'm not sure if this has already been discussed but I was reading a thread similar to this issue. They said it was the MAF or throttle body. I'm really hoping it's not the throttle body. So my issue started a couple days ago. I went to to turn on my car and the first thing i hear is a loud clapping. Almost like an engine knock but the car has been fine since I got it, and I havent been dogging it at all. So that was the first thing I noticed along with a high idle. Normaly when I turn my car on it idles high for about 10 seconds and goes back down on a cold morning. But this was different because my whole car started vibrating. I let the car warm up a bit and I drove to school. On the drive home, no lights came on the dash but I got a "try slow down or shift up" message. The whole ride felt really roguh which is unsusual because this car rides very smooth.
The problem went away when I got in my car to drive back home. But then it came back. And now it's still here. I got the codes pulled for it and it came back with a long list of codes whihc is also strange because when I checked the codes about 2 weeks ago, I didn't have any. So here's the codes and any help at all would begreatly appreciated.

My main reason for thinking it's the throttle body is because when I was driving home last night, I was coasting about 50mph when all of a sudden my gas pedal wasn't adding speed. My speed was dropping so I just down shifted the car until I got to the red light. Once at the light I did a quick restart of the engine and we're back to normal. Drove home since I wasn't too far but ever since then my car has been very rough.

wooshybum · Post by **wooshybum** » 28 Mar 2018, 07:17

Update: I disconnected the Mass Airflow Sensor to test it out and see if things would go back to normal, and the only thing that changed was the high idle on cold start up. It would drop immediately with the MAF disconnected. The car still felt really rough. I'm thinking it could be a spark plug failure, and hat may be why I'm getting so many fuel related codes?

Post by **chrism** » 28 Mar 2018, 07:37

Before spending a dime on parts, I would try two things:

Clean the throttle body (if you haven't done so already).

Unlatch the ECU, spray the contacts with electrical cleaner, and re-install. A special (inexpensive) tool is required to unlock/relock the ECU.

wooshybum · Post by **wooshybum** » 28 Mar 2018, 07:52

I haven't gotten to cleaning the throttle body. I'm going to do that today, I just have to locate it.

Post by **cn90** » 28 Mar 2018, 08:22

- For Throttle Body Cleaning, I wrote DIY in the XC90 forum. All the tricks are there. Very easy.

Post by **regent** » 28 Mar 2018, 11:44

If I may chime in, since codes read misfire on #2 for lean conditions (either too much air or too little fuel), I would look into these two:

1. Injector # 2 not firing - quick check wiring first (unplug connector and then re-connect, inspect wires visually) or bad/clogged injector (check continuity); wiring issue could be intermittent
2. A significant air leak - disconnected or ruptured vacuum hose

Just ignore that 'Recommended MAFS Replacement' from Autozone

wooshybum · Post by **wooshybum** » 28 Mar 2018, 12:51

So I replaced the coil and the Spark Plug but it was still giving me issues after I restarted The car. When I came back inside to check the forums, I read what regent said and I unplugged the conection for the fuel injector for cylinder 2 and lo and behold, engines running like perfect again. All I did was unplug and plug in the fuel injector connection, now I'm worried because idk what the issue was after having spent all this money.

Post by **erikv11** » 28 Mar 2018, 17:40

The issue was probably just a loose connection on the fuel injector connector. Keep an eye on it, if it doesn't come back over a couple weeks then pretty much for sure that was it.

If you swapped in a cheapo coil I would put the factory one back one, save the new one for troubleshooting purposes.

Post by **abscate** » 29 Mar 2018, 05:46

Clear all those codes and see what comes back when/if the check engine lights comes on

When you have a ton of codes, you will get led astray for sure

Post by **regent** » 29 Mar 2018, 06:35

Glad you sorted it!

Just for good measure, when putting the factory coil back in - like erikv11 advised - I would replace all plugs as a set while at it.