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Hey guys! Im working on this Mazda CX7 and i checked fuel pressure and my gauge is jumping all over the place, Has anyone experienced something similar? Here's the link to the video I recorded
youtube.com/shorts/2rHfV8wRR9o?feature=share
Interesting. I can't say that I have seen anything quite like that! Does the gauge become stable when the engine is not running?
"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer." I have learned more by being wrong, than I have by being right.
Hey Chad. Yes, when the engine is not running the pressure is at 60psi and I did another test too. So the gauge is connected between the inlet of the HPFP and the hose which comes from the fuel tank, when I blocked the high side after the gauge and before the HPFP the pressure in the low side stabilize at 65 psi. I have to codes for fue pressure but I do have codes for a lean condition but im a little confuse because the upstream O2 sensor PID reads -0.030mA. This cx7 uses a wideband o2 sensor. STFT and LTFT shows 20-23% both and no matter the rpm the fuel trims and o2 pid data doesn't change at all, idle or underload they are the same. O2 sensor is new.
This cx7 stalls randomly at idle or when you getting to a stop but, put on N or P and cycle the key and starts normal.
I'm not sure but this could be multiple different issues but honestly I hope they are related.
Thanks for the answer Chad
Looking at scan data, what are your "actual" and "desired" Fuel Rail pressures? Does the actual pressure align with the desired pressure?
I have to codes for fue pressure but I do have codes for a lean condition
What codes are you getting?
"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer." I have learned more by being wrong, than I have by being right.
I dont remember if my scan tool shows the desired pressure but i remembered watching the high pressure PID. I will get those numbers and i will post them tomorrow! about the codes i got:
P2187
P2177
P2006
P2009
P0131
P0113
I already know why P2006 and P2009, the connector of the switch is broken and the plastic bracket that activates the switch is broken too, i tried to weld a metal piece to make it work but i didn't work (i think we need to replace the whole intake manifold) and I don't know how that might affect it, but in any case, Should this problem result in a rich mixture? I'm not sure if I'm correct, but if this system doesn't work, the runner flaps are normally open. This fault probably won't affect my fuel trims?
P0113 i checked and I couldn't see any out-of-range data; I assume this code might be a consequence and not the root cause.
Mazda says that when accelerating to 3000 rpm and releasing the accelerator, the sensor should read a peak of 0.25 mA during deceleration, but that never happens in this case; the signal doesn't change from -0.030 mA.
This vehicle is a perfect case study, and I'd love to be able to solve it. I've searched extensively for information and help from others, but I haven't found much from other workshops or online. Most of the technicians I've consulted have simply told me it's a problematic vehicle. At some point, this vehicle was very poorly maintained and had numerous turbocharger issues, vacuum leaks, and cylinder misfires. The wiring harness near the alternator was damaged three times due to belts damaged by oil leaks.
As soon as i get the fuel pressure PID i will post them in here, Thanks have a good weekend!
Also i apologize i reply and post 3 times the same by accident.
I got the live data from this Mazda and i couldn't find a PID for Desired Pressure it only show me the Actual pressure which stays around 900-1000 psi i know the pressure is higher than normal but the engine wasn't fully warmed up, and the trims are at 20 and 25%. The high pressure could be the computer trying to compensate for the lean mixture. I checked the live data with a TOPDON scanner, but it's not showing the desired pressure either.
"P2187
P2177
P2006
P2009
P0131
P0113
I already know why P2006 and P2009,"
Please include the code definitions for anyone who may wish to assist. No body just knows what all these codes mean. You may get more help if every one who is reading this knows what you are dealing with.
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