new to me, 98 M3

[Bassboy3313]

Very cool setup with but cars

[cpandrewschmidt]

New euro steering wheel installed!  

[cpandrewschmidt]

Hi all, So some small updates and much frustration.  Put a new Alcantara headliner in, looks great.  Don't have any pics yet.

Now onto the trouble, and where I need some experts on here help.  Check engine light came on a few days ago.  Codes P1188 at first, now both P1188 and P1189. Reading online this could be a slew of things from Vacuum leak, o2 sensor, injector, MAF, fuel delivery, etc.  Car for the most part feels OK.  I just haven't had enough time with it to tell if it's running more poorly than normal.  

Here's what I've done so far.  Searched tubes for vacuum leak found a crack in the throttle body boot, patched it real well with JB so I do think that's fixed.  Code still came on.  Had spare O2 and spark plugs so I changed those out last night, cleared codes and reset battery.  Codes both came back this AM.  Kind of out of cheaper ideas to check.  I would think injectors are OK as they were new with the SC about 22,000 miles ago.  I hate to throw money at parts just guessing unless they're routine maintenance items.  I have a fuel filter coming next week I'll be throwing on.  

Anyone on here around the Madison area that has an e36 M3 I could try their MAF to see if it's that before buying a new one? 

I also took some "live" data from my code reader.  I have no idea what any of this means.  Most of the numbers jump around and what shown is only just because I snapped a picture at that time.  I'm not sure if I'm relaying what's showing correctly.  

Thanks for the help.  Afraid this car might not have been a great idea.....

[B C]

DTC_CNT  is Diagnostic Trouble Code count, so you have 2 codes stored.
FUELSYS1 = Fuel System 1 is running in Closed Loop

FUELSYS2 = Fuel System 2 is running in Closed Loop. Not sure what the question mark denotes or what constitutes Fuel System 2 since Motronic doesn't control open/closed loop on bank 1 and bank 2 separately.

LOAD_PCT is the commanded fuel load. I suppose this value may be of use to see if your injectors are maxing out at full boost/high rpm. This is a low number since presumably you are at idle

ECT is engine coolant temperature. Good assuming you are at operating temperature/gauge is reading near the middle.

SHTFCK1 is anyone who vapes

SHRTFT1 is your short term fuel trim, how much fuel is being added or subtracted from the base fueling map during your current running session. This number being negative likely means a slightly rich condition is requiring fuel to be pulled for this trim. The numbers are reasonable. no alarms here.

LONGFT1 is your long term fuel trim (this is what gets reset when you reset the ECU) which is the stored value for the fuel being added or subtracted from the base fueling map based on the driving initially done after the last ECU reset

Same thing for Bank 2, you notice that the LONGFT2 is the same as LONGFT1 because its a universal fuel addition/subtraction.

RPM is RPM so 708 RPM is good assuming this is at idle

VSS is vehicle speed sensor (located in the diff) you are presumably parked so a value of 0 is good

Short Term Fuel Trim, Bank 2, Sensor 1 is  0.8%

Spark Advance is 13 degrees BTDC which is a typical range for idle advance.
IAT is intake temperature, 73 is a reasonable temperature so no alarms here.

*****PROBLEM MAF is showing a flowrate of 0.01 lb/sec. my math says that 10 lb/min should be roughly  1hp. At idle your engine should be creating at least 15-20hp.   So your MAF is borked, your wiring has an issue, or there is a SEVERE air leak somewhere.

Throttle Position is at 17% which tells me that you have to keep your foot on the throttle a bit at idle to keep it alive because of the presumed MAF problem

*****PROBLEM Bank 1 o2 sensor is reading 0.94 V which is somewhere in the neighborhood of 10.5:1 AFR, far too rich

*****PROBLEM Bank 2 o2 sensor is reading 0.125 V which is somewhere in the neighborhood of 18.0:1 AFR, far too lean
If you are confident that your upstream O2 sensors are good, you should consider checking the resistance from the ECU harness to the O2 Connectors. The Bently manual should cover that test and tell you which pin it is.

*****PROBLEM SHRTFTB2S2 short term fuel trim is way too high. this combined with the bank 2 sensor voltage seems to point to an injector/fuel delivery problem on bank 2. Perhaps a bad injector or bad injector harness wiring.

Overall I get the feeling you have more than 1 problem. I would check the injectors and injector wiring first. Use a stethoscope to listen for each injector firing as the engine runs and better yet, pull the injectors and fire them into a container while attached to the rail to see the flow for yourself.

Check the MAF and MAF wiring, then if it is still acting up (showing a very low value in the live data) then perform a smoke test to rule out vacuum leaks.

If the O2 voltage and fuel trim is still far off at this point then check the O2 sensors and O2 sensor wiring as well as check for ignition problems.

If it is misfiring at all you can disconnect individual coil packs one at a time to see which cylinder the misfire is on (when the engine doesn't react to the coil pack being disconnected that is your problem cylinder) to help isolate the misfire.

FWIW: This is just my armchair mechanic input trying to help you out and I could be completely wrong.

[cpandrewschmidt]

Thanks Snap.  Useful info for sure.  I'll check the wiring again around everything.  The car does have an open air cone filter.  Would that effect the MAF readings as an "air leak"?  

Both upstream O2 sensors are brand new Bosch so I think those are OK.  Going to grab some injector cleaner and see if that helps. 

I'm going to try rigging up a DIY smoke test this afternoon.

[B C]

Open element filter will only cause grief with a MAF if its an oiled element like an ITG or K&N style filter, or if its a Spectre brand.
The oil can get whisked into the intake stream and coat the MAF element with a thin layer of oil which can damage it or cause bad readings.
Spectre brand filters are just horseshit and don't belong on anything nicer than a Cobalt.

Remember to cap off the intake and exhaust. Plastic grocery bags work unless you only ever BYO canvas bag to Whole Foods because one time I saw a fish choking on a plastic bag and  the Almond Milk at Pick N Save is low quality and don't get me started on Piggly Wiggly.

[jc43089]

cpandrewschmidt said:

Thanks Snap.  Useful info for sure.  I'll check the wiring again around everything.  The car does have an open air cone filter.  Would that effect the MAF readings as an "air leak"?  

Both upstream O2 sensors are brand new Bosch so I think those are OK.  Going to grab some injector cleaner and see if that helps. 

I'm going to try rigging up a DIY smoke test this afternoon. 

The filter should not affect the reading of the MAF.  Unless it sheds oil.

Could the wiring have gotten switched and the o2 sensors are adjusting the wrong bank?  I am not sure if there is only one fuel trim value or one for each bank so this might be bogus but it seems odd that one is low and one is high if they are both new.

[damnboy037]

Been looking for a TS for a while, wanted to get one for my s50b32 once I figure out how to get it running, good find.

[GunMetalGrey]

I feel sick after looking at those pictures long enough...
I'm with Brian on this one as your flow rate is very low, and I don't know if you were on the throttle to keep it alive or if that is a bad reading.

Do you have the air filter directly attached to the maf? I have head that doing that can eliminate the laminar flow that is usually maintained the stock intake. Would it be enough to cause that low of a reading? Not sure.

[i_love_cars]

cpandrewschmidt said:

Thanks.  Yeah I did a bunch of research on that SC before getting the car.  It's pretty highly regarded on the bimmerforums forced induction page.  Made me feel more comfortable about buying someone else's mods.  The SC only has about 20k miles on it.  It is due for an oil change before I really start driving it.  Its definitely a different type of feeling compared to the turbo 135i, In a good way, very linear power.       

what, you mean you don't like the instant, always-on blast of torque trying to kill you in the 135 ?!?!?! Say it isn't so 

Seriously, my 1er tried to kill me a lot. 

Glad to hear you are close enough to Lake Mills to make it out to some C&C this year. The C&C there is actually how most of us who are normally too busy to connect get an excuse to meet up and hang out for a few hours. I also really enjoy it

[i_love_cars]

Snap said:

SHTFCK1 is anyone who vapes

seen it 

i'm dead 

[patsbimmer1]

I know you said you JB welded that boot really well but do yourself a favor and replace the boot if it's been torn at all.  This may or may not be your issue but the boot is already weak if it's torn where you could see it.

[m42b32]

Snap said:

****PROBLEM MAF is showing a flowrate of 0.01 lb/sec. my math says that 0.15 lb/min should be roughly 2hp. At idle your engine should be creating at least 15-20hp.   So your MAF is borked, your wiring has an issue, or there is a SEVERE air leak somewhere.

Throttle Position is at 17% which tells me that you have to keep your foot on the throttle a bit at idle to keep it alive because of the presumed MAF problem.

At idle with my foot off the gas my '99 M3 sits at 17%/18% throttle. Not sure on the rest of the numbers though. When I get back from my trip I can see what my car reads for the rest of the parameters you posted to compare

[cpandrewschmidt]

hi all, back from the weekend.  Update.  Hooked up a DIY smoker.  Paint can with some tubes hooked up to a compressor at 4 psi then blew smoke into the chamber.  Worked well except I couldn't introduce enough smoke with just a cigar.  Didn't really need the smoke I was able to hear one small leak out of one of the SC tubes.  Fixed that and checked again couldnt hear any air leaking out of anywhere else and pressure definitely built up.  Intake tube fix held fine.  Drove car again and light still came on, this time only code P1188.  

Filter is a K&N that probably needs to be cleaned and lightly oiled again.  But not sure that would be my problem.  Next step is to check injectors I suppose.  I put some injector cleaner in the tank.  Also tried to clean MAF.  For the O2 sensors I only unplugged 1 at a time so I know I put those back in the correct spots.

Car still seems to run just fine, drove it about 250 round trip up north.  who knows on this one!  Kind of stumped at this point.

[cpandrewschmidt]

Did a little more testing on the code reader.  For my MAF reading i watched it while driving home.  At 55 mph it would hover between .04-.05 lb/s  Not sure if that's normal or low.  Under reasonably heavy acceleration it'd get to .11 lb/s.  So, it appears to at least be reading something.  I unplugged it at idle and the car started to spit and sputter badly, so it's regulating a little bit I assume.  Would software for the SC mess with this?  No one on here around Madison I could swing by to test a known good MAF before dropping a couple hundred on one?  I'll also be around brookfield this Friday about 2pm and heading back to Madison   

I tried the screw driver on the injector trick to see if they're ticking properly.  Couldn't really hear crap over regular engine noise.  You'd think they'd be OK since they're only 20K miles old when the SC was put on.  Haven't flow tested them yet.  I suppose that's next. 

Happy to entertain other ideas!  New fuel filter comes Friday as well, maybe its not getting the fuel it needs?

[Daggerty]

What's the part number on your maf, I might have one.

[cpandrewschmidt]

Daggerty said:

What's the part number on your maf, I might have one.

Real OEM is saying 

13621703275

but I'll double check what's actually on mine since the SC kit supposedly came with a new one. 

Another note, I see my reading is .01 lb/s. I'm looking online for normal readings and see readings are all recorded in lb/hr.  Not sure if that makes my reading OK.

[B C]

thanks for pointing that out, lb/min is the most frequently used unit for engine airflow (besides CFM) and I totally overlooked the fact that your scanner outputs lb/sec.  .05 lb/sec is roughly 30hp which is reasonable for cruising.  "reasonably heavy acceleration" at .11 lb/sec is only 60hp which is only considered reasonably heavy acceleration in an air-cooled beetle.

if you can get a WOT reading and give an approximate RPM  during the reading we can get a better gauge as to whether the MAF reading is reasonably or not. So far it appears reasonable at low throttle openings  but not heavy acceleration.

[cpandrewschmidt]

thanks SNAP, i'll do that today!

[cpandrewschmidt]

OK, took out for lunch.  A bit hard to read while driving and going to WOT but I noticed it as high as 24.1 lb/s.  If I had to guess my rpm around 4500-5000 range at that point.  Again hard to drive and not crash while watching three things.  So, it may have peaked higher I just didn't catch it.  I also took some revised data while cruising at 55 mph.  Not sure if that tells anymore of a story.  

One other little thing I've noticed.  When I come off throttle and into neutral from stop and go traffic the rpm will dip very briefly to about 400 rpm and recover immediately to normal idle. Only does this in stop/go.  Doesn't do it if I come into neutral from higher gears like 4 and 5 and drop into neutral.