"aftermarket sensor" is enough for me to go down that rabbit hole. Is it the correct application? Are the two sensors reversed? Is it designed with the correct scale? Was it carved from the finest Chinesium, and has no hope of being correct?
"aftermarket sensor" is enough for me to go down that rabbit hole. Is it the correct application? Are the two sensors reversed? Is it designed with the correct scale? Was it carved from the finest Chinesium, and has no hope of being correct?
Looks like I misremembered the voltage from yesterday. Here are the readings KOEO.
I'm having trouble sanity checking myself from my phone, but...
Why are raw throttle position voltages 1 and 2 so far off? Are they supposed to agree, or is it something funky like one counting up and the other down and sanity checking is that they should sum to reference voltage?
Whatever it is, I see it doesn't apply to driver demand...
Those MAP values don't make any sense to me. Engine off, you've got half an atmosphere upstream and .169 bar manifold.
Our is that actually KOER?
I do not like the KOEO etc acronyms. Grumble.
That was engine off.
This is engine on (running rough, throttle has no affect and doesn't change map values much).
One TPS voltage goes up while the other goes down.
Compared to the same running condition with full throttle.
Accelerator pedal sensor values:
The values for the two internal sensors are:
Hall Sensor 1 - approximately 0.5 to 4.5 volts Driver Request
Hall Sensor 2 - approximately 0.5 to 2.0 volts Plausibility Check
This is the manifold air pressure when it is running rough:
What does "set point" mean?
I'm trying to read those as just... current pressure values. And that shows the manifold as being under boost? At idle?
The only thing I'm really sure if is that I don't trust my understanding of the fields. But I can't think of any way those MAP values are sane, can you?
That is another confusion of mine. It can't be the actual reading but I don't know what it would be adjusting.
Based on how the ignition angle set point value behaves I assume it is the amount of correction it is requesting.
Example: Running rough, ignition angle set point is maxxed at +72.
Once it gets into closed loop and smooths out the set point fluctuates between -2 and +2 or so as it idles smoothly.
.
I have not noted what the air pressure set point values do when it is in closed loop.
Jesse Ransom (FFS) said:I'm having trouble sanity checking myself from my phone, but...
Why are raw throttle position voltages 1 and 2 so far off? Are they supposed to agree, or is it something funky like one counting up and the other down and sanity checking is that they should sum to reference voltage?
Whatever it is, I see it doesn't apply to driver demand...
Throttle position voltages are always on a different scale from each other, for error checking reasons.
MAP sensors will be different readings because the sensors have different scales due to the forced inductionness. It looks like it is more like what most manufacturers would call a manifold pressure sensor and a barometric pressure sensor.
Pete. (l33t FS) said:MAP sensors will be different readings because the sensors have different scales due to the forced inductionness. It looks like it is more like what most manufacturers would call a manifold pressure sensor and a barometric pressure sensor.
That makes sense, but it seems weird to me that they barely differ between off and running.
EDIT: to remove all the blithering because the "set point" stuff must means something other than usable data, otherwise we wouldn't see it moving around a bunch while the voltages barely move, right?
The MAP values not changing much from engine off to running rough is the very low vacuum while it is running rough.
On first start when it runs well both MAP voltages drop down then when it starts running rough they are closer to atmospheric. When I had the other scan gauge on it that just displayed vacuum it was around 2.5inHg. Once it starts adding fuel in closed loop and runs well it has a more normal vacuum reading.
I'm going to try adding more fresh gas to it since I am out of other ideas.
I may also go to the junkyard and pull an OEM coil since the one on it has been replaced but is aftermarket.
How difficult is it to remove the valve cover?
In reply to Pete. (l33t FS) :
Shouldn't be too difficult. Is there a way to verify the cam timing is correct like that or would I be doing that to look for something else?
In reply to EvanB (Forum Supporter) :
That's the direction I'm thinking, as something to check.
My only experience is with the non forced induction cars. And to be honest I don't remember if it was even running poorly but setting a cam position fault.
It's worth a shot to see if anything looks amiss.
It has started to try to clear up, before it would start and die/almost die. Now it starts, almost dies, and tries a second time before going into the low idle or shutting off.
These plugs certainly don't look like it is running lean. Bad picture both they are all very black and sooty.
Compression from Cyl 1-4:
158
164
156
166
So maybe once it enters closed loop and fuel trims go up it is actually running so rich that it reads lean which is why the o2 sensors are nearly at 0.0v. That is still confusing since that is the only time it idles well except initial start. It will rev fine on initial startup but after a couple seconds it won't take throttle, doesn't matter if it is idling at 1500rpm and then just drops down or if the throttle pedal is pressed and it is revving at 4-5k rpm it will just shut down and not respond.
I did go to the junkyard today and pull an OE coil off the mini there and there was no change.
After more digging through old threads on forums searching for a variety of things I found one reference that the "ignition angle set point" maxed out at 72 is just the default when the DME isn't controlling it and it runs on the base map. That explains why it is always maxed when it is in open loop.
Possibly something is messed up with the stock maps and causing it to not run right? I haven't found any good info yet on if it is possible to reflash a stock map on it.
Back to the MAP sensors: We believe one to be actual MAP, and one to be barometric reference. Er, right?
We also think that they (understandably) could be on different scales because barometric/upstream shouldn't need to get significantly above 1 bar.
BUT, the software clearly shows them both on a 2.4 bar scale.
AND it shows them reading very differently from one another KOEO, when different voltages could be explained by different scales, but they're disagreeing on *pressure in hPa*. And KOEO should be about atmospheric everywhere, but whether it's the car misunderstanding the sensors or INPA misunderstanding the car, both sensors are showing significant (and differing) vacuum.
I'm back to thinking that Set Point must have some meaning, but that enough items give a sane-ish value that I think these are still nominal readings of the sensors.
The voltages look... plausible, even if they don't hit Pete's targets for normal 1 and 2 bar sensors (again, INPA scale is 2.4, Evan mentioned 2.5?), but the actual pressures suggest... what? That the car is expecting different voltages than we are for a given pressure?
Having a remarkably hard time finding a definitive answer about whether these sensors are the same or differ; one is used as MAP/Temp, but at least one source specifically states that both are TMAP sensors with temp ignored in some locations/on some models. Napa shows one entry for Barometric and three for MAP, and different part numbers for the one brand that shows in both categories, BUT items in both categories have the same "Located On Thermostat Housing" note, and one of the MAP sensors' note is "upstream sensor."
EDIT: To add that this all makes me think that there's a bad/incorrect sensor or sensors going on here. Or, of course, wiring/grounding. I think it's likely they're supposed to be the same sensor, it seems even more likely that they're both 2.4 bar sensors even if not identical, even though baro shouldn't need that, and I think they should probably agree on voltage KOEO, but should almost certainly agree on pressure KOEO.
The MAP sensors should be different. Everyone that sells the OE sensors sells them as Pre or Post supercharger. The Post supercharger (in the intake) is the one that is 2.5 bar and has the temp sensor. I sent out to check yesterday to see if the temp was correct and it was reading 0°C while that was the ambient temp so I assume that is right, it changes as the engine warms up.
I haven't found any good reference on what the manifold air pressure set point is doing. One forum post (about an audi) had similar readings and was questioning why calculated load was reading as 40% at idle. My calculated load also reads 40-50% at idle while alternator load is 100%. I am assuming it is because it is running so poorly that it is trying to keep it alive. As is customary on forums the thread had no resolution so I don't know what the fix was for that.
Have you cleaned all the grounds? Dumb question, but im wondering if the ecu or sensors are seeing wrong stuff due to wonky resistance values to ground
In reply to Dusterbd13-michael (Forum Supporter) :
Some, not all. I know that should have been one of my first steps but I've just been so hung up on the fact that it starts and runs so good then just shuts down that I haven't tried some of the easier stuff.
I did verify that based on the part number on it the TMAP sensor is a Facet replacement for the correct application.
It may be a heat related ground issue. As stuff warms up, it expands juuuuussst enough...
EvanB (Forum Supporter) said:The MAP sensors should be different. Everyone that sells the OE sensors sells them as Pre or Post supercharger. The Post supercharger (in the intake) is the one that is 2.5 bar and has the temp sensor. I sent out to check yesterday to see if the temp was correct and it was reading 0°C while that was the ambient temp so I assume that is right, it changes as the engine warms up.
I haven't found any good reference on what the manifold air pressure set point is doing. One forum post (about an audi) had similar readings and was questioning why calculated load was reading as 40% at idle. My calculated load also reads 40-50% at idle while alternator load is 100%. I am assuming it is because it is running so poorly that it is trying to keep it alive. As is customary on forums the thread had no resolution so I don't know what the fix was for that.
"Calculated load" is basically VE, but mass. So if the cylinder can hold 100 milligrams of air under some standard-day type conditions, and the calculations/measurements say 40 milligrams of air are going in, that is 40% calculated load.
That is about normal for idle, by recollection, for most engines.
Still no progress. I unplugged the MAP sensor and was excited initially because it idled well longer than normal but went back into the same routine.
The manifold air pressure set point when it is running well is around 300-400hpa. Then when it starts to idle low with extremely low vacuum it goes back to the 1000+.
When it is running rough the calculated load is 90-100%.
I'm not thinking any of those numbers mean much to me, probably more a reflection of it barely running.
I smoke tested it again for fun and found no leaks.
I'd plug everything in, clear the codes, start it and see what it does.
If it runs like crap until it starts ratcheting up the fuel trims, start flowing propane into the engine to see if it will run well AND drop fuel trim back down.
If BMW had their hands in the engine controller, it may run poorly until you clear codes (and therefore adaptive memory).... AND you may need to go into manufacturer specific, and generic OBD-II, and clear everything out, because BMW engineers were obstinate and had "their" computer controls AND "American" controls in the same computer and they would get kind of schizophrenic. Like when the corpus collosum gets severed in a brain.
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