karayjay

So this is gotten progressively worse in the last five days. One of the issues is if I知 rolling the car will stay at 1200. RPMs if I put it in neutral it stays at 1200. She comes back down to 15 and then jumps up to 2000 RPMs. And then correct down to 1000. Issues here not sure whether we池e talking map sensor or vacuum leak.


Yesterday I did a smoke test so I didn稚 see anything come out of there other than the map sensor area, which is normal

Now I was thinking the fuel injectors, but it痴 both sides bank one and two so I知 just looking for opinions. Or if anyone痴 gone through this.

It is pretty annoying in traffic if I let go the break, the car will travel at 1200 RPMs by itself if I read the engine when she settles down in a few seconds

I do have another 2006 so I could take the maps sensor off of that one and put it on here as a test I guess

I also have an extra intake case, but I highly doubt it because it痴 been great since my last intake change a year ago.



my other suggestion could be Mass flow air sensor. Maybe it痴 that one I知 kind of going for that instead of the map sensor. I have noticed that when you start restricting or when that acts wonky, it does affect the idle greatly.

performance wise everything else is fine it痴 more of just an idol scenario. The car responds well to acceleration when I need it.

jimyj

Hey karayjay, it sounds like a classic case of either a vacuum leak or a sensor playing tricks on you. Your description of the erratic RPMs, especially in neutral, definitely raises a red flag for potential issues with the mass airflow (MAF) sensor or the manifold absolute pressure (MAP) sensor. Given that both banks are showing lean codes, I’d lean towards checking the MAF sensor as it could be giving you incorrect readings, causing the engine to compensate and lead to that high idle behavior. Since you've already done a smoke test without finding leaks, there's a good chance that the MAF is at fault, especially if it's not accurately measuring airflow.
It's great that you have another 2006 CLK for spare parts; swapping the MAP sensor to verify is a smart move. Just be careful, as getting too wrapped up in sensor diagnostics can sometimes leave you chasing your tail! If you haven’t done so already, a full system scan could be beneficial to gather more data on any underlying issues. The youcanic full system scanner works particularly well for these models, and while Xentry provides thorough diagnostics, it does come with a steeper learning curve. Good luck, and hopefully, you’ll kick that idle problem to the curb.

karayjay

So here痴 an interesting update. I reset the codes. I got my parking garage. I started it up now. She痴 barely idling. It痴 almost like a misfire scenario but it痴 only an idle. The car performs fine after you go 4 miles an hour and up. No check engine light, which is really bizarre.

looks like I値l just start swapping parts like I suggested earlier, but this is bizarre. I致e had that mass airflow sensor on me with that when you read the engine **** all the way through my car if I read the engine, it revs fine but for some reason when I知 sitting at a set of lights, it痴 bucking idling really rough. But if I throw it in neutral I can manage. Then I throw it in the light green and I no problem. So it seems more like an issue.

karayjay

So I have an update unknown good mass airflow sensor still runs crappy, but when I remove the connector and run without it, it runs a lot better


So with the MAF delete it runs fine. I gotta figure out why now
now I gotta figure that question out. Why does it run better with the MAF out?

JD-CLK

Rip off the air box and inspect all vacuum lines, and especially the EGR hoses. also clean your MAF Sensor. Vacuum lines that are cracked, worn, or overly stiff will cause issues. Go the the autoparts store and pick up a whole bunch of new vacuum line for like a few dollars and just replace it all

karayjay

I get it believe me it seems like a vacuum leak all day long and I would do that but the problem is I did a smoke test yesterday on a homemade kit that I made. We have no smoke coming out anywhere on the manifold except for the airflow sensor in the back which is normal.

No, I could do the other trick where you run the engine and you spray carburetor fluid wherever their vacuum lines and the car runs even worse. Now you know you got a vacuum leak. I haven稚 gotten there yet

I知 gonna try one last thing is take a mass airflow sensor off my other car. I had spares from a previous issue, but I remember one time and this is crazy. I had a problem with the car and I purchased a mass airflow sensor. That was complete crap in one car but in another and they are the exact make and model except three years difference.

I found that bizarre. But so far too mass flow sensors have the exact same scenario that idol.

Not to make this a story, but I know that in most cases when you have a bad mass airflow sensor, the car runs like absolute crap. I mean, you can稚 even drive it mine you could drive. It was just the idle that was a problem, stopping at a set of lights you have to throw it in neutral because it ran a little rough. The second light turned green. I put it in gear. The second I got over 8 miles an hour. Seven car ran fine plenty of acceleration.

karayjay

well, here痴 the picture to prove sometimes it痴 right in front of your face. You just don稚 see it as I said before. Remember when I said I was doing a smoke test for a lean bank one lean bank two error that I致e been getting from last three months. when I put the air cleaner, I think I hit the hose and it moved moved it enough that it popped off again. This is the hose I use for my smoke test.
by the way, if anybody痴 wondering, this is the best hose to do a smoke chest with anyways problem solved. I guess driving to work it was connected and somehow I hit a couple bumps and it popped off who knows but the problems fixed. Now let痴 see if the lean Bank one lean Bank two comes back. That might be fuel injectors.

JD-CLK

I've owned multiple different CLK models, 99% of the time lean banks is EGR related. Dirty, or Clogged EGR, or damaged hoses will cause lean codes. either on one or both sides.

karayjay

Finally, a great answer. I appreciate that a lot that can稚 hurt to clean out. I might clean that out on my other one too because I have four performance issues and I clean the fuel injectors. I just gotta find out where the EGR valve is. Maybe I値l just replace it but then again cleaning it out would be more fun. Thank you so much for this info. This is exactly why I come here.

JD-CLK

There are hoses near the end of the valve covers towards the cabin of the vehicle, they are thick rubber ones and there is two, one on each side.

karayjay

Yeah, I知 looking forward to taking these out and stick them in my car carburetor bucket but I知 soaked for about half an hour cleaning with my brushes and toss them back in. I appreciate this a lot. And I知 wondering if this is causing an issue on my other CK that, sometimes hesitates off the line and sometimes it痴 perfectly fine