My battery ran out while I was away for a month. When I jumped it, it started acting really weird… The idle was really lumpy, so I figured that the ems calibration got erased. I re-uploaded the calibration that I made a backup of as soon as I got the car tuned but it was still doing it. I’ve included some logs I recorded, as well as the calibration file…

Immediately after taking those logs the car wouldn’t even idle. I have to give a little gas constantly for it to stay on… So I did a compression test and they were all within 60kPa of each other (the range was 580-640kpa but the manual states that the standard value should be 1128kPa... maybe due to the extensive internal mods???).

The plugs were extremely black, so I replaced them with some new bpr7es gapped to .6mm and now it idles again (albeit still lumpy).
Cams are 264/272, for a full list of mods, please see this page: https://www.evolutionm.net/forums/sh...d.php?t=102480

I noticed that in the logs, the o2 sensor readings don't change... could this be related to why it's running really rich?

Can somebody please tell me if you see anything in the logs and calibration that might be the problem?

I would really appreciate it!! I'm stuck over here for a few years, and they're not familiar with the EMS at all, and it's really rare and expensive to find anybody that knows anything about this stuff here.

 

If the O2 sensors are not reading correctly and you are using O2 feedback, it is likely the problem. Turn off O2 feedback and the engine should run fine (assuming the O2 feedback was not being used to correct for a poorly tuned map). If that fixes it, then figure out the reason your wideband is not working properly.

 

Thanks for the reply.
It was tuned by a reputedly good tuner, but he tuned it very conservatively to keep in mind that the car was going to be shipped halfway around the world to a different elevation and climate.

Did you check out the logs? Was I correct about the O2 sensors being stuck? I'm new to interpreting all that stuff... How would I turn off the O2 feedback?

And could a stuck coolant sensor produce similar results?

 

Actually, I think O2 Feedback was already turned off...
Under the "Options - O2 Sensor FB" window, "O2 FB Control" was unchecked.
Is this what you were referring to?

 

Hello Arpad,

i replied to your post @ AEM Forum.

I want to believe , that there is something wrong with the O2 sensors, but in your map you didnt use it. so thats not the reason.
Look at the post @ AEM Forum, there are a few hints.
Its really cold in germany right now, so that can also a problem.

I having sensors in stock in germany, but it looks like there is an problem with the O2 controller.

So contact me by PM.

 

Yeah, that is what I meant. I didn't have a chance till now to review some of your logs and cal file.

Are you sure your compression test was accurate? 580 to 640 kPa is really low. Is the cam timing and everything ok? Sensors are all reading accurately? If the O2 feedback is off and the engine runs badly, then either the tune changed, or something on the car has changed (mechanical issue, sensor malfunction, etc). Or perhaps the tune was never correct for those conditions to begin with, but that doens't sound like the case.

Your compression could be low if the engine has been washed with a lot of fuel.

 

german_evovii: thanks for the reply! I replied to you on the AEM forums.

John Reed: Yeah, the compression test seemed accurate, all cylinders were within that range. Unless the compression measuring device is bad? But that was also the readings that the shop got when I first got the car and had it tested by them since I didn't have a compression tester available. It should be fine as long as it runs and they're within 98kpa of each other, right? About the sensors: I'm not sure what the normal is since I'm new to this. I did notice that the O2 sensor #1 and O2 sensor #2 seem to not change from a certain value (18V and 10V correspondingly) but would the car even run if that were the case? Do you see anything odd in the sensor logs? I checked the alternator output with the car running and it was only about 3v. I think that's why the battery has been dying constantly, but would a faulty alternator somehow cause it to run really rich?

 

Do you run that map daily? And your car runs fine ?

 

I was... until all this happened. Since then, I've only taken it for test drives to see if it's changed. I'm waiting for a new alternator to get here, maybe that might solve something? Can you think of anything else? I think I'm about out of things that I can think of...

 

Well according to your compressoin test values...seems like you are losing compressoin?? The only way to tell if everything is okay is to do a compressoin test...and since your values are low - you should think about pulling your cylinder head and taking a look at those pistons

 

When I first bought the car, I had it compression tested and got those exact same values... it had just been completely rebuilt by Buschur. I then had the EMS tuned and it has been running perfect for 8 months now, it's only been since this battery thing that anything has changed.

What would make the compression identically low across all four cylinders?

 

Are you sure the MAP sensor is calibrated correct now? It could of changed and it would cause a rich condition. Something just to check out. I wouldn't worry too much about the compression test if its the same as it was when you bought it.

 

The logs you provided aren't telling me much, other than you definately have a problem with your map sensor. I would also look at your coolant temp and make sure it's not defaulting to some crazy warm up value. You have a TON of fuel on warm up.

 

Sorry about the delay in response, I don't know why evom didn't tell me that there had been replies...

GTVEVO: Thanks for the suggestion, I will look into recalibrating the MAP sensor. Would it be something that I could do easily?

Jason Siebels: Do you think recalibrating the MAP sensor like GTVEVO suggested will solve the problem? I will check coolant temps and post results. Is there anything else that could also cause too much fuel on warm up?


I just received and installed the new alternator today (what a PITA!!) and the voltage readings from it seem to suggest that it is now running correctly, yet the idle is still lumpy and it's still running rich. It's running so rich that brand-new plugs got so fouled on a 20 minute trip to my buddy's house (driving very conservatively) that I stalled on the autobahn after 15 minutes and had to put some fresh plugs in (lucky foresight that I brought some).

In thinking about the cause of these problems: could they from the possibility that when I jumped the car I reversed the polarities by accident since I was in a hurry and it was dark? Would that fry the alternator and potentially other things? The fuses in my stereo and amp were blown and I had to replace them... Could reversing the polarities during the jumpstart have caused a short somewhere that would be causing these problems?

The more I think about it, the more I think that I might have reversed the polarities since I am colorblind (the worst kind) and red and black have a tendency to flip-flop in my vision especially under low-light conditions. I am kicking myself harder than Beckham...

 

Np, The first thing you can do is just simply turn on the key and see what the MAP sensor reads. If it reads 0psi +/- 1 psi you are probably ok on the MAP sensor. To test it further though I would get a hand pump and start checking the PSI to voltage range on the sensor. The defaut setting on mine was .5v - 4.5v and after I tested it the right setting for me was .8v - 4.8v to have it read correctly.

There is several things that would cause the car to be rich, it sounds like it is rich all the time though and not just during warmup. Could be several things but the MAP sensor would be the first thing I checked. Fueling would be the second, maybe the high pressure relay is triggered and the fuel pump is now always in high pressure mode? Don't know it is just another though.

Be aware connecting cables in reverse will cause some very ill affects with electronics. It would be very hard to tell what all was bad but it could be serveral more items and it could of damaged the ECU as well. You might have to send it in for sevice or to atleast have it checked out.