Bimmerfest BMW banner

Injectors or maf?

  • Injectors

    Votes: 0 0.0%
  • Maf

    Votes: 2 100.0%
  • Sell lol

    Votes: 0 0.0%
1 - 20 of 38 Posts

·
Registered
Joined
·
107 Posts
Discussion Starter #1 (Edited)
Ok so ongoing issue. 2001 530 133000 miles. Been having ses light with bank 1 and 2 over limit lean condition. Found and repaired. Cracked valve cover by cylinder 5. Or so I though. Hooked up my creator 310 now have short term reading of -.06 on 1 and -.09 on 2 with long term hovering around 11.0 on 1 and 12.0 on2. How can fuel be taking away and adding at same time. Makes no sense. I have smoke tested this thing to no end only leak was valve cover. Other than that u name it I have replaced it trying to end my rough morning idle and lean condition. What do u make of these fuel numbers. My fuel pressure was perfect as well running and holding pressure engine off. Battery numbers perfect aswell.. o2 sensors cycling perfect and after cat holding steady at .74 as well.
 

·
Registered
Joined
·
4,055 Posts
Simple way to think about it:
-short term is what it is adjusting now
-long term is the sum of what has been needed in the past

Not really the way it works but overall valid.


2001 750iL DD74441
Stock

RIP: 2003 540iA Sport GS56111
H&R front springs, Ultimate Cup Holder, Euro Dash & Armrest, Grom, BavSound Stage1
 

·
Registered
Joined
·
107 Posts
Discussion Starter #4
That is an informative video. But nothing explains how stft could constantly be negative(reducing fuel) and the ltft well into the plus(lean or adding fuel). I have yet to find a valid conclusion for this. What broken part is giving these false and misleading readings?. Injectors? Maf?. Bad rings? Anyone ...bueler????
 

·
Registered
Joined
·
4,055 Posts
You measured it once.
Fuel trims constantly vary based on inputs, environmental conditions, and where you are on the map.
You had enough of a lean condition that it set off the SES. Unless you clear the trims it will take time to normalize.
It normalizes by subtracting from the fuel it has added.


2001 750iL DD74441
Stock

RIP: 2003 540iA Sport GS56111
H&R front springs, Ultimate Cup Holder, Euro Dash & Armrest, Grom, BavSound Stage1
 

·
Registered
Joined
·
107 Posts
Discussion Starter #6 (Edited)
I have my code reader constantly plugged in. I reset it every few days. After about twenty minutes of driving. My stft is taking away fuel on a constant basis but my long terms jumps to 12.0 lean condition and climbs as I go faster. This is impossible to subtract and add at same time lol. I have been monitoring this obsessively for weeks and I drive on the same god forsaken l.i.e. everyday. Variables don't change. I just don't want to throw parts at it anymore
 

·
Registered
Joined
·
265 Posts
That is an informative video. But nothing explains how stft could constantly be negative(reducing fuel) and the ltft well into the plus(lean or adding fuel). I have yet to find a valid conclusion for this. What broken part is giving these false and misleading readings?. Injectors? Maf?. Bad rings? Anyone ...bueler????
Have you ever replaced any of these parts, crack in the piping will cause the same CEL.
 

Attachments

·
Registered
Joined
·
107 Posts
Discussion Starter #8
Completely new ccv system. New intake mani gaskets. All new orings everywhere. Plugs. Cleaned idle control valve . Rebuilt vanos. Rebuilt diss. Newer battery.new v valve cover gasket. New solinoids for vanos. Dropped subframe for oil pan gasket.new intake air sensor. This actually all sounds ridiculous just to find why my trims are way off and kinda rough idle
 

·
Registered
Joined
·
4,055 Posts
Completely new ccv system. New intake mani gaskets. All new orings everywhere. Plugs. Cleaned idle control valve . Rebuilt vanos. Rebuilt diss. Newer battery.new v valve cover gasket. New solinoids for vanos. Dropped subframe for oil pan gasket.new intake air sensor. This actually all sounds ridiculous just to find why my trims are way off and kinda rough idle


I have my code reader constantly plugged in. I reset it every few days. After about twenty minutes of driving. My stft is taking away fuel on a constant basis but my long terms jumps to 12.0 lean condition and climbs as I go faster. This is impossible to subtract and add at same time lol. I have been monitoring this obsessively for weeks and I drive on the same god forsaken l.i.e. everyday. Variables don't change. I just don't want to throw parts at it anymore


So Bmw uses a slightly different model of lambda integrator than normal. Bmw uses load so stft is lower loads and ltft is higher load. So they can be directly adjusted independently. They still interact but can be independent.
If it is a vacuum leak then proportionally the leak will be smaller at higher loads/rpms and the trim should be adjusted less. If you are seeing the opposite then something else is probably going on: fuel pressure, clogged injectors, incorrect throttle reading, or many more.


2001 750iL DD74441
Stock

RIP: 2003 540iA Sport GS56111
H&R front springs, Ultimate Cup Holder, Euro Dash & Armrest, Grom, BavSound Stage1
 

·
Wingnut
Joined
·
3,703 Posts
right around 50 PSI is correct. you may have a fuel delivery problem, that at higher rpm's or loads it becomes inadeguate. this would explain low stft, high ltft. possible, not definitely your issue. is there any way you can put together a fuel pressure gauge that you can see while driving? or fuel injectors may have a buildup that wont allow a higher rate delivery correctly.

howdy Mr TAB..long time. hope life is going well for yall.
 

·
Registered
Joined
·
107 Posts
Discussion Starter #13
I could try to watch the fuel pressure while driving. Thanks that is my next plan of attack. I have my own smoke machine will smoke it AGAIN but pretty sure i took care of all vacuum issues thank you mattmar1 and everyone else...to be continued.
 

·
Wingnut
Joined
·
3,703 Posts
and as youre monitoring the trims all the time, discount the long term readings for the moment, let us know what the short terms do over the rpm range.
 

·
Registered
Joined
·
107 Posts
Discussion Starter #15
Honestly maybe my creator is broken but the stft really never move they are locked at -.06 and -.09. I even watch graph mode they don't move it's the ltft that change drastically with load
 

·
Registered
Joined
·
4,055 Posts
That is suspect...
Undo a vacuum line and see if it moves the stft. (Of course reconnect after done with test)

Howdy Matt. New job locked in the secure basement... fun times. Hope all is well with you and the new guy is treating you well (great rescue!).


2001 750iL DD74441
Stock

RIP: 2003 540iA Sport GS56111
H&R front springs, Ultimate Cup Holder, Euro Dash & Armrest, Grom, BavSound Stage1
 

·
Wingnut
Joined
·
3,703 Posts
That is suspect...
Undo a vacuum line and see if it moves the stft. (Of course reconnect after done with test)

Howdy Matt. New job locked in the secure basement... fun times. Hope all is well with you and the new guy is treating you well (great rescue!).


2001 750iL DD74441
Stock

RIP: 2003 540iA Sport GS56111
H&R front springs, Ultimate Cup Holder, Euro Dash & Armrest, Grom, BavSound Stage1
yes this is very suspect. try what TAB says and let us know what happens. something is funky here. you did say the pre cat O2's are varying correct? did anyone happen to do any work on the car that may have possibly reversed the 2 pairs of connectors?

yeah id read about the new job in your post a while back in the nothing thread, sounded like it was gonna isolate ya...had a few tasks like that,, know how it limits ones access to the outside world when at work. yeah the new guy is awesome, one high energy beast. got the DNA back, hes about 80% american staffordshire terrier, 15% bull terrier, and 5% bulldog. he be one handsome fun beast.
 

·
Wingnut
Joined
·
3,703 Posts
Honestly maybe my creator is broken but the stft really never move they are locked at -.06 and -.09. I even watch graph mode they don't move it's the ltft that change drastically with load

one thing i use when troubleshooting is the torque app(full functional app for droid is $5.99, and youll need an ELM 327 bluetooth OBDII adapter, about $20, for apple its the dashcommand app) it gives you easier and more wide ranging access. for example, one can look at all 4 fuel trims #'s, as well as pull up rpm, temp etc data at the same time. quicker access vs having to switch screens all the time. i havent even seen my creator in quite a while, loaned it to a friend and hes still got it. tween torque and INPA ive pretty much got all bases covered.
 

·
Registered
Joined
·
1,222 Posts
I have a C310 Creator that does not function correctly on certain settings.

Oil Temperature and the 2 Engine Coolant Temperature readouts in the General settings are way high even before I start my car.
Like out of the park high, it tells me your engine is overheating and it hasn't even been started yet after sitting for 24 hours....LOL.

The Engine Coolant Temperature reading in the Transmission settings reads correctly though,
it matches the On Board Computer (OBD) reading.

I have a BAFX WiFi OBDll diagnostic interface dongle, it's a good company with great customer support and they don't use a cheap ELM 327 chip like you might run across from the inter web auto parts sales sites, you can get it for Android or Apple IOS. I paid a bit more for it cause I didn't want to get burned again like I did with the C310 Creator. $21.99 for Android, $25.99 for Apple IOS.
I use it in conjunction with the Fusion App, Android or Apple IOS.

I concur with Mattmar and Angry Bear, create a vacuum leak and see what does or doesn't happen with the fuel trims. If no change in the STFT then you might have a bum C310 unit.
Crossed up o2 connections can mess things up as well.
 
1 - 20 of 38 Posts
Top