DTC's P1140 and P0170, and a DISA q

[familytruckster]

So I have the 1140 and 0170 codes. So far I have replaced:

Intake boot
Injector o-rings
PCV valve
All of the Vaccum lines
Cleaned the MAF
Intake gaskets
Checked for vacuum leaks with carb cleaner, found none.

The LT fuel trim is at -22%, but does that mean lean or rich? The O2 sensors seem to be fine, I watch them change, same with the MAF. (though I need to check what the flow is supposed to be) Any ideas? Anyone have the flow data from a scanner for the MAF?



The other issue I seem to be having is an intermittently working DISA. The car pulls great sometimes under 2500, and is a complete dog other times. From what I've seen, the DISA is normally in the open (high rpm) state, and at lower RPM an electric vacuum pump closes the valve. I'm thinking the hoses need to be replaced, and I did notice a check valve on it that could also go bad. Anyone ever mess with repairing one?


and lastly, I had the OBC beep at me and go to the temp display and the *F was flashing, what does that mean?

[tiFreak]

Originally Posted by familytruckster

and lastly, I had the OBC beep at me and go to the temp display and the *F was flashing, what does that mean?

it does that below 37 degrees to let you know there might be ice on the road

[familytruckster]

Ah, that's interesting! I thought something else broke.

Well, I guess I'm going to check some more sensors, and run some fuel system checks now.

[familytruckster]

Ok, from the reasearch I've done the car seems to think it's running rich and is cutting fuel. I've checked the injectors and the fuel system, they all check out. It's possible the O2 sensor is toast, but getting it out has proved troublesome (not surprising) I think its also possible the cat is clogged from all of the coolant from the multiple head gasket failures. I tried to take the 02 sensor out to check the pre and post cat pressure....but getting the 02 sensor out has gotten tough. I've heated the bung and the sensor only moves a little bit. I'm getting a bit frustrated.

[familytruckster]

Well, new 02 sensor, new crank/cam sensors, new plugs...Exact same issue.

[familytruckster]

Anybody?

Some MAF readings at various RPM's would help, most OBDII scanners can display that info...

[xxxJohnBoyxxx]

PM me your email and I will send you LM-2 logs of my MAF. You will need the reading program which I will send a link for. John Smith

The Logs have. RPM, MAF, Knock sensors & wide-band O2 real time on multple pulls and normal city driving

[familytruckster]

Pm sent, Thanks!

[xxxJohnBoyxxx]

Did that help? PM me or email if you need help. All values can be converted to volts or % or graphed from those logs. John Smith

[familytruckster]

Haven't had a chance to drag out my windows laptop and look at the logs.

Those logs are FI though right? At a given rpm or load value the there will be a bit more air going through the maf on your car. except no load and idle, I would imagine.

[familytruckster]

Well, it was the MAF. Even though it looked good on the scanner, the MAF was bad.

[Fab]

Hi All,

I have a 316I 1.9L E36 year 2000 and have a P0170 code. Initially had a o2 sensor code, O2 sensor has been changed and now have P0170 "Check Fuel supply system".

Vacuum leak and PC valcve done 9 month ago, check for any other air leak with smoke machie, nothing. the garage checked the fule pressure, all good. The car runs great, no problem with IDL

Thinking of the following:
-Change oile filter
-Check if air filter has oiled and could dirty teh MAF
-Clean the MAF

any ideas ? thanks in advance

[familytruckster]

If you have a scantool look at the fuel trims. If it's lean (negative number) , it's the MAF.

Other thing you can do is toss another MAF on there and see what happens. Which is what I ended up doing.

[Fab]

Thanks for the tips much appreciated

[Fab]

Hello, well looks like th code is still coming up...

I have done the following so far

-changed pre catalytic ox sensor
-check catalytic converter- ok
-check vaccuum leaks- ok
-checked fule pressure- oK
-Put a MAF test unit (before replacing) nothing changed code still back up
-Change couple of hoses at fuel pressure reg that at a tiny tiny sweat with smoke machine on, code came back after 200 Kms
-Smoke machine, no leaks
-Cheched harmonic balancers (just in case too much vibration, replace the serpentine belt was due anyway even if not related)


The car is running fine, no probs at IDLE just under 1000 rep but steady, fuel consumption seemed improved since o2 sensor changed.

Not sure what to do next apart from taking it to BMW official dealer an geting charge 250$ an hour and start all over again from sratch...


any ideas would be greatly appreciated guys

Fab