My Honda J-series engine (2007 V6) has rough idle and sometimes misfire DTC. I noticed that the idling engine "Intake manifold absolute pressure" is around 27 kPa. During normal highway driving at constant speed, I see fast fluctuations without reason (going up to 75 kPa or 85 kPa for a fraction of a section and then drop to around 27 kPa). When engine is not not running, I get 100 kPa (close to 1 atm), My LTFT is +14% or sometimes +20%. Is my MAP sensor bad? If so, why do I get 100 kPa and 27 kPa which are considered normal for non-running engine and idling engine? Overall fuel economy is around 20 mpg on par with similar cars. I hope someone can shed a light on this. Thanks.
I did a computer relearn after cleaning mine. Took about 50 miles of a semi limp mode to calibrate itself. I'd recommend looking into how you initiate a relearn in your vehicle. With mine, I had to do some specific presses on the start button to initiate it.
Below are the approx math figures of MAF values, for my 1.8 litre supercharge engine, running at manifold pressure at 0 psi. 3000rpm = 41 g/sec, 2500rpm = 34g/second, 2000rpm = 27g/second, 1500rpm = 20g/second. These MAF values can increase by 1.5 times when supercharger kick in an ramps up manifold pressure to 8psi. These figures is on a sticker which I place on the dashboard for occasional quick check when I put the car on auto cruise mode to required rpm. Whenever the manifold pressure is within -0.5 to +0.5psi the MAF readout given out by OBD2 matches closely with these value value. The on-the-dashboard mounted OBD2 could could also show throttle body position, IAF, injection advance, short or long fuel trim, etc etc. At hot engine idling rpm of 750, without air conditioner switch on, on P position, the MAF is about 4.5 to 4.7g/second vs throttle body at 14.9% open vs MAP at -7.3psi. This value is useful if there is a partial vacuum leak or MAF is dirty etc etc. BTW, to me, this video is really not deep enough for it to be really useful to anyone.
Good job🤝💯🔥💪👍
Thanks 🔥
Damm Rick and his air fuel mix. Knock it off Rick dmmmit 😂
My Honda J-series engine (2007 V6) has rough idle and sometimes misfire DTC. I noticed that the idling engine "Intake manifold absolute pressure" is around 27 kPa. During normal highway driving at constant speed, I see fast fluctuations without reason (going up to 75 kPa or 85 kPa for a fraction of a section and then drop to around 27 kPa). When engine is not not running, I get 100 kPa (close to 1 atm), My LTFT is +14% or sometimes +20%. Is my MAP sensor bad? If so, why do I get 100 kPa and 27 kPa which are considered normal for non-running engine and idling engine?
Overall fuel economy is around 20 mpg on par with similar cars. I hope someone can shed a light on this. Thanks.
Hi there!I have got exactly the same situation with my car.Was it the map sensor?Thanks in advance!
👍🏾👍🏾👍🏾🔥🔥🔥
🔥
I juat changed mine, do you need to drove a few miles for it to adjust?
I did a computer relearn after cleaning mine. Took about 50 miles of a semi limp mode to calibrate itself. I'd recommend looking into how you initiate a relearn in your vehicle. With mine, I had to do some specific presses on the start button to initiate it.
Below are the approx math figures of MAF values, for my 1.8 litre supercharge engine, running at manifold pressure at 0 psi.
3000rpm = 41 g/sec, 2500rpm = 34g/second, 2000rpm = 27g/second, 1500rpm = 20g/second. These MAF values can increase by 1.5 times when supercharger kick in an ramps up manifold pressure to 8psi.
These figures is on a sticker which I place on the dashboard for occasional quick check when I put the car on auto cruise mode to required rpm. Whenever the manifold pressure is within -0.5 to +0.5psi the MAF readout given out by OBD2 matches closely with these value value.
The on-the-dashboard mounted OBD2 could could also show throttle body position, IAF, injection advance, short or long fuel trim, etc etc.
At hot engine idling rpm of 750, without air conditioner switch on, on P position, the MAF is about 4.5 to 4.7g/second vs throttle body at 14.9% open vs MAP at -7.3psi. This value is useful if there is a partial vacuum leak or MAF is dirty etc etc.
BTW, to me, this video is really not deep enough for it to be really useful to anyone.