[kemosabe421]

Running the car on the track today and the check engine light came on. Checked code and it said "P0107 minifold pressure/B". No loss of power or performance. Cleared the code, went back out, check engine light came back on. Toggled DIC to % of boost and it showed zero boost. Ran the car hard and it still showed zero boost with no feeling of lack of performance. Suggestions appreciated.

Kemo

 

[TomatoSoup]

Some information, first please. Do you have a tune? Is it the GMPP tune with swapped (and crimped connection ) sensors? If so you prolly need to solder those connections.

If not, it's something wrong with either wiring (maybe worn insulation and shorts) or the sensor itself.

Here's another thread with info: http://www.skyroadster.com/forums/f5/p0107-fault-code-40275/

And a post with more: boost problems!! Help!! - Pontiac Solstice Forum

 

[kemosabe421]

TomatoSoup. Thanks for the reply. My Red Line is stock.
Something I didn't put in my original post, I notice a
faint smell of gas.

Kemo

 

[atr32]

I am having the exact same problem. First I got the P0139, but that went away when I checked the outlet pipe from turbo to ic. Then I went out and floored it and going 135kpa uphill the light came on. Checked it and had one missfire on thrid cylinder and P0107. Now P0107 is lit constant.

When hooking up to obd it looks like its sending 101kpa barometric pressure constant, I am thinking the sensor is toast and is sending this just to make the car run at all.

Now, witch one of those bad boys goes first, the one on the inletpipe from turbo or the one on the manifold?

I am running BSR tune, K&N internal filter and somekind of 4 pipe ****ty ebay catback. Oh, and its an Opel GT.

 

[atr32]

So I went out, ran a couple of runs and I deffo think its the sensor on the manifold for me. It is supposed to variate in airflow but doas not, barometric pressure stays the same no matter the load.

Tried cleaning it and no go. Although it was pretty clean from the start.

 

[atr32]

Changed the MAP on the intake manifold, code gone, car runs smooth! Boost comes on early and no stuttering during launches!

 

[Robotech]

atr32, glad you found the problem. Keep in mind that while the sensor in the cold side charge pipe is a MAP, the ECM in the LNF only uses it for air temperature (Intake Air Temp2 value...this is checking the temp of the air entering the engine after being compressed and cooled by the intercooler. Intake Air Temp 1 is taken at the MAF in your air intake to the turbo). For your issue, only the sensor in the manifold reads the air pressure.

So what kind of Kpa are you seeing now? Should be much higher than 135.

 

[TomatoSoup]

atr32, glad you found the problem. Keep in mind that while the sensor in the cold side charge pipe is a MAP, the ECM in the LNF only uses it for air temperature (Intake Air Temp2 value...this is checking the temp of the air entering the engine after being compressed and cooled by the intercooler. Intake Air Temp 1 is taken at the MAF in your air intake to the turbo). For your issue, only the sensor in the manifold reads the air pressure.

So what kind of Kpa are you seeing now? Should be much higher than 135.

This is not what *I* understand for the LNF operation. AFAIK, the ECM uses the 'first' T/MAP sensor (nearest the I/C) for both pressure and temperature. It then uses the 'second' MAP sensor for pressure-only as a backup/confirmation. If the two pressure readings differ by a certain amount, the ECM throws a code/goes into limp mode.

 

[Robotech]

This is not what *I* understand for the LNF operation. AFAIK, the ECM uses the 'first' T/MAP sensor (nearest the I/C) for both pressure and temperature. It then uses the 'second' MAP sensor for pressure-only as a backup/confirmation. If the two pressure readings differ by a certain amount, the ECM throws a code/goes into limp mode.

That's the first time I heard this. It would make a lot more sense but everyone I've ever talked to said the one in the pipe only does air temp and the one in the manifold does pressure. I always wondered if the one in the pipe did just temp then why would GM change it out with a three bar in the GMPP tune upgrade? Thought there was more to it but could never get confirmation on it so I ASSuMEd I was wrong.

So, to clarify with the LNF, the MAP reading in the ECM is generating from the MAP only sensor in the manifold and the MAP/IAT sensor in the cold pipe is feeding IAT2 and another reading we don't see for comparison purposes to the MAP in the manifold?

This is much like the downstream O2 sensor after the cat that is only there to verify catalytic converter function by comparing the emissions coming out of the cat versus the emissions going into the cat as read by the upstream O2 which also plays a role in closed loop fueling, correct?

 

[TomatoSoup]

That's the first time I heard this. It would make a lot more sense but everyone I've ever talked to said the one in the pipe only does air temp and the one in the manifold does pressure. I always wondered if the one in the pipe did just temp then why would GM change it out with a three bar in the GMPP tune upgrade? Thought there was more to it but could never get confirmation on it so I ASSuMEd I was wrong.

So, to clarify with the LNF, the MAP reading in the ECM is generating from the MAP only sensor in the manifold and the MAP/IAT sensor in the cold pipe is feeding IAT2 and another reading we don't see for comparison purposes to the MAP in the manifold?

This is much like the downstream O2 sensor after the cat that is only there to verify catalytic converter function by comparing the emissions coming out of the cat versus the emissions going into the cat as read by the upstream O2 which also plays a role in closed loop fueling, correct?

In addition to your '3 bar swap' argument, if both MAP sensors were not used for pressure, then there'd be no reason to wire the pressure sensor signal wire up on both!

My understanding (could be wrong) was as I said, the primary sensor for BOTH pressure and temp, is the first one on the charge pipe. The secondary (confirmation) sensor is the one on the manifold.

 

[Robotech]

In addition to your '3 bar swap' argument, if both MAP sensors were not used for pressure, then there'd be no reason to wire the pressure sensor signal wire up on both!

Yea but GM does do weird stuff on occasion. Had a short that was blowing the fuse for the MAF on my Grand Prix. Looked at the factory wiring diagram and it showed that wire being the only wire on the fuse so I traced it from the MAF back to the fuse box and found no short...but I DID find a second wire connected to that fuse. Followed that back all the way through the entire engine harness to find out it was tied to the rear O2 sensor which had been hit by something and was causing the short...but no mention of this shared circuit in the diagram. LOL

My understanding (could be wrong) was as I said, the primary sensor for BOTH pressure and temp, is the first one on the charge pipe. The secondary (confirmation) sensor is the one on the manifold.

This would be odd as the LE5 uses the same manifold sensor in the same general location for the manifold air pressure reading. Since manifold pressure could be different from charge pipe pressure (since you have the throttle body in between the two) I would think the manifold sensor would be your primary Manifold Air Pressure reading and the charge pipe sensor would be for comparison purposes mainly under boost.

 

[atr32]

atr32, glad you found the problem. Keep in mind that while the sensor in the cold side charge pipe is a MAP, the ECM in the LNF only uses it for air temperature (Intake Air Temp2 value...this is checking the temp of the air entering the engine after being compressed and cooled by the intercooler. Intake Air Temp 1 is taken at the MAF in your air intake to the turbo). For your issue, only the sensor in the manifold reads the air pressure.

So what kind of Kpa are you seeing now? Should be much higher than 135.

Ty! Have to say its easy working on the kappas compared to the double of everything rb26dett.

Yeah I figured that out on the go, had not yet made any logs when I wrote that. Also ty for the ECM open/closed loop / boost control illustration, that was very nice explained and illustrated!

I did log some runs with ScanXL professional but somehow I doubt the data. It says max intake manifold pressure was 217kpa and max rpm was 10926. That makes me doubt any kind of numbers. Speed 232km/h. I am pretty sure max speed was 130 tops. Even the logged spark map has logged -17.5 @ 8000RPM and 200kpa.

I´l make some more runs tonight unless it pours.

I had some missfires aswell I think it was gasoline quality the sparks looked fine (had some gasoline smell to it since tha car was going rich) other then that :cheers:

DIC reads 170kpa in 2nd gear around 7k rpm, and then 160 in 3rd. I think thats how BSR tuned it, conditions where perfect for high boost (high moist and 15degrees C)

 

[atr32]

This is not what *I* understand for the LNF operation. AFAIK, the ECM uses the 'first' T/MAP sensor (nearest the I/C) for both pressure and temperature. It then uses the 'second' MAP sensor for pressure-only as a backup/confirmation. If the two pressure readings differ by a certain amount, the ECM throws a code/goes into limp mode.

I am just gonna say thats not what happend to me.

I got the P0107 and no intake manifold pressure and was not in limpmode. Car ran to max rpm on wot, the trouble was cruising and idle where the car went very rich.

They did indeed differ but no limpmode.:surprise:

 

[TomatoSoup]

I'm not sure what the actual symptom/result would be. My statement "the ECM throws a code/goes into limp mode." was meant to imply either/and/or

 

[atr32]

I'm not sure what the actual symptom/result would be. My statement "the ECM throws a code/goes into limp mode." was meant to imply either/and/or

Oh! Gotcha !:cheers:

 

[Robotech]

Yeah I figured that out on the go, had not yet made any logs when I wrote that. Also ty for the ECM open/closed loop / boost control illustration, that was very nice explained and illustrated!

Glad they helped. Just keep in mind those illustrations are highly simplified as to what is really going on inside the ECM. They are meant to give the average Joe a basic idea of hour our ECMs manage the engine's fuel and spark operation.

I did log some runs with ScanXL professional but somehow I doubt the data. It says max intake manifold pressure was 217kpa and max rpm was 10926. That makes me doubt any kind of numbers. Speed 232km/h. I am pretty sure max speed was 130 tops. Even the logged spark map has logged -17.5 @ 8000RPM and 200kpa.

I´l make some more runs tonight unless it pours.

I had some missfires aswell I think it was gasoline quality the sparks looked fine (had some gasoline smell to it since tha car was going rich) other then that :cheers:

DIC reads 170kpa in 2nd gear around 7k rpm, and then 160 in 3rd. I think thats how BSR tuned it, conditions where perfect for high boost (high moist and 15degrees C)

You need to look and see what your KPA is immediately after shift. The K04 generally peaks in the lower RPMs then tapers off as RPMs increase. Thus your KPA value at near redline would be much lower than the KPA value around your post-shift RPM. Either way, some of those figures are WAY off...10K rpm? I wish! LOL

 

[slobalt09]

So I went out, ran a couple of runs and I deffo think its the sensor on the manifold for me. It is supposed to variate in airflow but doas not, barometric pressure stays the same no matter the load.

Tried cleaning it and no go. Although it was pretty clean from the start.

Barometric pressure should stay the same unless you're going up in elevation (being sea level to the mountains for example)