Bank 1 = Lean, Bank 2 = Rich
#1
Bank 1 = Lean, Bank 2 = Rich
Vehicle - 2004 Infiniti G35 sedan with a 6 speed manual transmission.
I had my motor swapped and I came across two codes - P0171 (Bank 1 lean) and P0113 (Intake air temperature high input).
Fuel trim data shows bank 1 is running lean while bank 2 is running rich.
Short term fuel trim in bank 1 = 25% and Short term fuel trim bank 2 = -25% at 2500 rpm. At Idle, these percentages are lower but equal in magnitude.
I have always had an intake and exhaust installed. I put a JWT lightweight flywheel and clutch while the engine was being replaced.
This is really odd and no one knows whats going on. I would really appreciate any help or advice.
I had my motor swapped and I came across two codes - P0171 (Bank 1 lean) and P0113 (Intake air temperature high input).
Fuel trim data shows bank 1 is running lean while bank 2 is running rich.
Short term fuel trim in bank 1 = 25% and Short term fuel trim bank 2 = -25% at 2500 rpm. At Idle, these percentages are lower but equal in magnitude.
I have always had an intake and exhaust installed. I put a JWT lightweight flywheel and clutch while the engine was being replaced.
This is really odd and no one knows whats going on. I would really appreciate any help or advice.
#2
I'd try cleaning your MAF and/or running the car without the MAF it should run in limp mode in a default rich condition I think. The P0113 stands out first at me, since that's integrated with it.
What are your long term fuel trims reading as well?
Then double check if you have any vacuum leaks.
What are your long term fuel trims reading as well?
Then double check if you have any vacuum leaks.
#3
#4
Did you still get the P0113 after you changed the MAF? If you got that code back then I'd check the wiring going to the MAF. Did you try running the car with the MAF unplugged? It should default to like +25 I think..
Try introducing something to get the fuel trims to respond and see what happens. Spray some carb cleaner or unlit propane into the intake (after MAF) and see if the computer starts taking away fuel. Pull a vacuum line and see if it starts adding fuel.
Try introducing something to get the fuel trims to respond and see what happens. Spray some carb cleaner or unlit propane into the intake (after MAF) and see if the computer starts taking away fuel. Pull a vacuum line and see if it starts adding fuel.
#5
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I would pull the plugs and make sure they all look the same, my suspicion is you will find one black plug (or wet plug) from a cylinder with an injector that's stuck open causing that bank to run EXTREMELY rich, OR the exact opposite, one scorched plug from an injector that's basically not working... OR BOTH!
#6
Hello All,
I appreciate the feedback and had some time to look at the car this weekend. Compression test showed all 6 cylinders can hold 120-150 psi. So that's a relief!
Changing the MAF and the connector plug triggered the IAT sensor code. I think there is a problem with the IAT sensor wires. I should have left this alone.
The fuel trim at idle is 0% on bank 1 and -15% at bank 2. When I start driving the car both banks show +25% and -25%. We checked for vacuum leaks but couldn't find any.
All three spark plugs on bank 2 were black. So does this mean all three injectors are stuck open? The spark plugs on bank 1 seemed fine.
I replaced spark plugs in bank 2 but I fear as I drive the car these too will turn black.
My heated 02 sensors show minor fluctuation in voltage. The lean side shows 0.1 V and rich side 0.9 / 1 V.
Could this also mean I have a bad pressure regulator or damper?
I appreciate the feedback and had some time to look at the car this weekend. Compression test showed all 6 cylinders can hold 120-150 psi. So that's a relief!
Changing the MAF and the connector plug triggered the IAT sensor code. I think there is a problem with the IAT sensor wires. I should have left this alone.
The fuel trim at idle is 0% on bank 1 and -15% at bank 2. When I start driving the car both banks show +25% and -25%. We checked for vacuum leaks but couldn't find any.
All three spark plugs on bank 2 were black. So does this mean all three injectors are stuck open? The spark plugs on bank 1 seemed fine.
I replaced spark plugs in bank 2 but I fear as I drive the car these too will turn black.
My heated 02 sensors show minor fluctuation in voltage. The lean side shows 0.1 V and rich side 0.9 / 1 V.
Could this also mean I have a bad pressure regulator or damper?
#7
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I think you have a compression issue, I'm pretty sure the numbers you want are between 150-180 with no more than 10% difference between the highest and lowest value.
Make sure you crank the motor over 7 times to get the correct value.
Retest compression to verify you are within spec, if not then there's your problem.
Make sure you crank the motor over 7 times to get the correct value.
Retest compression to verify you are within spec, if not then there's your problem.
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#8
Did you change just the MAF or the connector as well? The IAT is pretty important, since it tells the ECU what the air temp is.
I believe there are two dampers on the engine one per bank. The passenger side on the top is bank 1 and bank 2 if I remember right is on the driver side buried underneath some stuff. I'm not sure how to test that, since there is not vacuum line going to it if I remember correctly. You might have to tie in a fuel pressure gauge on that side or something to see if it's bad. I know to get an overall reading you tie into the fuel damper on the passenger side.
I'd try replacing that first and make sure you get a new o-ring. I highly doubt all those injectors are bad, you want to look for something that will affect the whole bank and that damper does come to mind.
Minimum compression is 142 and standard is 184.
I believe there are two dampers on the engine one per bank. The passenger side on the top is bank 1 and bank 2 if I remember right is on the driver side buried underneath some stuff. I'm not sure how to test that, since there is not vacuum line going to it if I remember correctly. You might have to tie in a fuel pressure gauge on that side or something to see if it's bad. I know to get an overall reading you tie into the fuel damper on the passenger side.
I'd try replacing that first and make sure you get a new o-ring. I highly doubt all those injectors are bad, you want to look for something that will affect the whole bank and that damper does come to mind.
Minimum compression is 142 and standard is 184.
#9
Yes, the pigtail/plug and the sensor were replaced. My mechanic tried to match the colors on the pig tail to the wire harness but this resulted in two new MAF codes.
He later matched the wires based on wire position and using the old plug/pigtail as reference. This led to the IAT sensor code. The plug/pigtail is made by Nisformance. I used the torque app to read the temperature stuck at -40 deg C. I think the wire mismatch we had earlier caused this.
I will redo the compression test but I am sure I won't see over 150 psi. This motor came from an AWD G35 sedan that had 100k miles on it. My car is a RWD 6MT. The ECU was re-flashed right after because of this fuel delivery issue.
I checked the parts store and they have one fuel pressure regulator and 2 dampers (driver and passenger side). Based on what I have seen so far this has to be a fuel delivery problem.
I was considering swapping the injectors (left to right) to see if lean / rich gets reversed.
What's the o-ring for?
He later matched the wires based on wire position and using the old plug/pigtail as reference. This led to the IAT sensor code. The plug/pigtail is made by Nisformance. I used the torque app to read the temperature stuck at -40 deg C. I think the wire mismatch we had earlier caused this.
I will redo the compression test but I am sure I won't see over 150 psi. This motor came from an AWD G35 sedan that had 100k miles on it. My car is a RWD 6MT. The ECU was re-flashed right after because of this fuel delivery issue.
I checked the parts store and they have one fuel pressure regulator and 2 dampers (driver and passenger side). Based on what I have seen so far this has to be a fuel delivery problem.
I was considering swapping the injectors (left to right) to see if lean / rich gets reversed.
What's the o-ring for?
#10
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#11
Yes, the pigtail/plug and the sensor were replaced. My mechanic tried to match the colors on the pig tail to the wire harness but this resulted in two new MAF codes.
He later matched the wires based on wire position and using the old plug/pigtail as reference. This led to the IAT sensor code. The plug/pigtail is made by Nisformance. I used the torque app to read the temperature stuck at -40 deg C. I think the wire mismatch we had earlier caused this.
I will redo the compression test but I am sure I won't see over 150 psi. This motor came from an AWD G35 sedan that had 100k miles on it. My car is a RWD 6MT. The ECU was re-flashed right after because of this fuel delivery issue.
I checked the parts store and they have one fuel pressure regulator and 2 dampers (driver and passenger side). Based on what I have seen so far this has to be a fuel delivery problem.
I was considering swapping the injectors (left to right) to see if lean / rich gets reversed.
What's the o-ring for?
He later matched the wires based on wire position and using the old plug/pigtail as reference. This led to the IAT sensor code. The plug/pigtail is made by Nisformance. I used the torque app to read the temperature stuck at -40 deg C. I think the wire mismatch we had earlier caused this.
I will redo the compression test but I am sure I won't see over 150 psi. This motor came from an AWD G35 sedan that had 100k miles on it. My car is a RWD 6MT. The ECU was re-flashed right after because of this fuel delivery issue.
I checked the parts store and they have one fuel pressure regulator and 2 dampers (driver and passenger side). Based on what I have seen so far this has to be a fuel delivery problem.
I was considering swapping the injectors (left to right) to see if lean / rich gets reversed.
What's the o-ring for?
Was the sedan manual or AT? I think you'd get a code, but the MT model has two extra sensors that are for exhaust timing.
I'd try to get a fuel pressure reading if you can. I had to buy an adapter kit for like 60 bucks to tap into the system and that way you can at least see if you are within spec (51 PSI).
The o-ring goes over the damper, so if you disconnect it for testing or replacement it will leak if you don't have one. I bought a kit from Harbor Freight and matched them up.
I think the regulator is located in the pump housing itself and the dampers just reduce the noise. If you can get reading from the pump before it hits the rail (at pump itself), bank 1, and then bank 2 that would probably give the most info for a proper diagnosis. Try adding unlit propane into the vacuum line and see how it affects your short term fuel trim or pulling a vacuum line and see what the values are.
I think you're correct with the idea about fuel being a possible issue as well, but just not sure if it's bank specific or affects everything. I had a regulator fail in my Audi and it caused my fuel pressure to run at 100PSI and both banks to be rich.
If you still get low compression trying adding oil to see if it improves.
#12
#13
I would get rid off all other problems that exist before trying to figure this out also. The IAT sensor is pretty important it will affect the fuel trims also.
The exhaust sensors in the manual are like the IVT solenoids for the intake, but deal with exhaust cam timing. You need a Consult or have to go to the dealer usually to reset the exhaust timing setting.
You said the ECU was flashed, so I'm assuming it was flashed to run an AT engine?
The exhaust sensors in the manual are like the IVT solenoids for the intake, but deal with exhaust cam timing. You need a Consult or have to go to the dealer usually to reset the exhaust timing setting.
You said the ECU was flashed, so I'm assuming it was flashed to run an AT engine?
#14
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