Author Topic: Chip with low octane aftermath questions!? (Read 5905 times)

n.wesl · « **on:** January 15, 2011, 10:23:00 AM »

So yesterday I installed my performance chip. It's supposed to be run on no less than 92 octane. I had maybe 5 gallons of the low octane stuff in there. I started her up and it ran fine. Smooth smooth smooth, so I figured if I babied it I could get her the mile to the gas station. Got there, filled her up to a little over half tank with 92. I figured all that 92 mixed with just the few gallons of low octane would give me an octane of somewhat okay levels. I start her up again and all is good. At this point the car is warmed up and I take her for a couple more miles winding it out to at most 6k. I arrive back home and all is good. A couple hours later I go to drive her again and it's giving me rough idle, a little surging, and just real rough up to about 2k. After about a mile or so I get worried I might have messed something up so I swap the stock chip back in. The weird thing is that even when I put the stock chip back in it's still rough now. Even more, it gave me the check engine light a couple times that then went off after I accelerated. Did I mess something up? I only went maybe 4 miles with the performance chip in there and wasn't even really pushing it hard. What do you guys think?

318lotis · « **Reply #1 on:** January 15, 2011, 10:57:54 AM »

did you do the stomp test with the check engine light?

i

n.wesl · « **Reply #2 on:** January 15, 2011, 01:20:42 PM »

I'm not familiar with the "stomp test", but the check engine light hasn't come on since. I've been told that perhaps this is because I didn't "reset" my ecu by unhooking the battery and then running for ten seconds then turning off. Also, apparently when you switch your ecu you need to drive it like ten or so miles to have it calibrate to your driving habits and since I haven't gone far that might just be it? Can anyone attest to this?

pdxmotorhead · « **Reply #3 on:** January 15, 2011, 09:02:36 PM »

Most chips have some static ram that holds some of the dynamic tuning data on the engine. You should have disconnected the battery cables before installing the chip, then when you restart the car, turn off ALL the electrical accessories. Start the car without touching the gas. Let it idle for about 5 minutes. Then drive it for at least ten minutes normally. Then drive it on the high way. It usually takes anywhere from 10 to 30 ignition on/off warm up driving cycles for the computer to fully calibrate. Depending on vehicle make and model.

Dave

n.wesl · « **Reply #4 on:** January 15, 2011, 11:33:13 PM »

Thanks Dave, I wish I would have known more about that procedure. So do you think my engine and everythimg is still okay? do you think this new found roughness will go away with time? It seems to be getting a little beyter with use (or is that just me getting used to it haha) and if so do you tthink it'd be safe to throw the new chip back in there but just follow all the correct procedure this time or?

Ryann · « **Reply #5 on:** January 16, 2011, 10:58:27 PM »

I'm betting your chip install and symptoms are unrelated.

n.wesl · « **Reply #6 on:** January 16, 2011, 11:08:00 PM »

What do you think it is? And I gave that a thought as well but they didn't start until after I put in the chip. It is odd it would run great then two hours later mess up though.

n.wesl · « **Reply #7 on:** January 17, 2011, 09:19:22 PM »

I did a stomp test and first came up with 1444. I've heard that's the no error found message. I turned it off and did it again and got 1241, air mass sensor. I consistently get 1241 now. Where is my air mass sensor? How should I go about cleaning it etc? I've read on other forums you use electrical contact cleaner.

n.wesl · « **Reply #8 on:** January 19, 2011, 02:03:12 PM »

Anyone?

inarticulate is · « **Reply #9 on:** January 20, 2011, 01:00:38 AM »

Its in the air intake past just past the air cleaner. Mercedes I was looking after had similar problems, solved with new sensor. Hope its just dirt but if not very easy to swap out.

n.wesl · « **Reply #10 on:** January 22, 2011, 12:27:54 PM »

Thanks. I'll try that. If I do end up swapping will one off a 325is work? I've got a parts one out back I could take one off of. And I put some fuel system cleaner in it the other day and it seemed to have helped a bit. My gas mileage has been HORRIBLE though ever since these problems arose.

Warsteiner · « **Reply #11 on:** January 22, 2011, 04:20:21 PM »

Which model and year car do you have? Did someone do a motor swap or is it original to the car?

Which "Performance chip" did you put in?

Why did you switch your ECU and was it the same ECU #?

For your air metering, all had AFM's (Air Flow Meter), until '96 and that point is mute becuase you'd have to flash your ECU at that point but you said you had a chip.

If you have a 318 why would even think that a 325 AFM or such could work?

You have not given us any reasonable information to even begin helping you. So much wishy washy info doesn't work. Go back to the basics and retrace your steps!

Give us a real synopsis of what you did and what you have changed and then we can start to point you in the right direction.

Where are you located? NOBODY ever puts where they are in there info�.I don't get it?? :confused: Maybe someone is local that could look at it for you??

Cheers,
~Ralph

n.wesl · « **Reply #12 on:** January 22, 2011, 11:48:39 PM »

I have a 91 318ic. The motor is original to the car. The chip was an ebay chip. I didn't switch my ECU, just put the chip in it. The # is 175. I do have a 318 but you never know, oftentimes different model cars have interchangeable parts and before I went and spent money on a part it's worth a shot just to ask if the one I have in my backyard would work. Sorry I'm not as knowledgeable as you. I didn't think my information was "wishy washy". I've told you what I know. If I knew what was going on I wouldn't be asking for help. I'm located in Louisville, KY. I know a lot of the BMW guys around town and have been to local meets but most of those guys deal with 325's if they are into e30.

Warsteiner · « **Reply #13 on:** January 23, 2011, 12:44:50 AM »

Hey I'm just trying to help:)
So you have a stock M42 with AFM. Ebay chips can sometimes be complete garbage and you have no idea what you're getting. In post #3 you say you switched the ECU? I agree that a lot of parts are interchangeable, but you have to kinda stick with 4-4cyl and 6-6cyl unless you're doing custom stuff. One, two or many things can cause your symptoms..... your O2 sensor, and now you have multiple issues due to a bad O2 sensor. A bad sensor will trigger your check engine light, give you a rough idle and surging. Did you by any chance unplug your AFM and forget to plug it back in? You're AFM not working correctly can give all symptoms also. Ryann can also be correct in that this just happened at the same time as something else and they are completely unrelated.
I would go back to your stock chip as you said that you have and start checking outside of that. If you can find another #175 ECU try that too. Check your connections on the AFM and the O2 sensor. That's where I would start.

HTH,
Cheers,
Ralph

n.wesl · « **Reply #14 on:** January 23, 2011, 10:30:44 AM »

I have heard this about ebay chips. I will say though that when the ebay chip was in there I did seem to notice smoother response at higher rpm and it was faster to get to the high rpms as well so I don't think it was complete garbage. Yeah I see where I said that now. Sorry, I meant to say that I just put the ecu back in. I have thought about the o2 sensor being a culprit. Who knows how old it is haha. Excuse my ignorance again, but would the o2 sensor off the 325 work or should I just try cleaning mine? The AFM has never been messed with to my knowledge and I have never unplugged it. I am back to the stock chip now and have been for a while. I'll check the AFM and then O2 sensor like you recommend. Thanks! Nolan