[Chaoscoordinator]

2004 Nissan Pathfinder
286k miles

The original issue

• the 4wd would engage while driving causing it to jolt then stall out. There was no issue restarting it after it died.

Initial Repair:

• unplugged relays going to 4wd so it won't engage - then the car would die out as driving and had a hard time starting.

Other things I've done to solve the issue:

• installed new fuel filter
• changed oil
• installed new air filter
• installed new fuel pump
• replaced valve covers
• replaced gaskets
• gutted catalytic converters
• installed 2 cam shaft position sensors -installed crank shaft position sensor
• installed spark plug anti foulers connectors (drilled out 1/2")
• extended rear o2 sensors

Problem I'm still having:

• Starts and idles without issue
• Once engine gets hot the RPMs jump and the car starts to spit and sputter giving it more gas doesn't make a difference

Any suggestions?

 

[Oldcivicjoe]

You are going go need a scan tool with access to live data, watch iat, ect, o2, map and maf data, see which one isn't corresponding to variables. Is the iat reading a few degrees above ambient temp? Does the ect increase as it warms up? Is o2 switching lean rich frequently? Does it go rich or lean when the sputtering starts? Does the map value change under load? Does the maf data correspond to engine rpms as it should?

 

[Chaoscoordinator]

You are going go need a scan tool with access to live data, watch iat, ect, o2, map and maf data, see which one isn't corresponding to variables. Is the iat reading a few degrees above ambient temp? Does the ect increase as it warms up? Is o2 switching lean rich frequently? Does it go rich or lean when the sputtering starts? Does the map value change under load? Does the maf data correspond to engine rpms as it should?

Thank you for responding. I just ordered a scan tool with live data. I'll check the numbers on what you recommended.

 

[Chaoscoordinator]

You are going go need a scan tool with access to live data, watch iat, ect, o2, map and maf data, see which one isn't corresponding to variables. Is the iat reading a few degrees above ambient temp? Does the ect increase as it warms up? Is o2 switching lean rich frequently? Does it go rich or lean when the sputtering starts? Does the map value change under load? Does the maf data correspond to engine rpms as it should?

I finally had time to run the test using the live data reader. The results are shown on the image. It's also pulling up the following codes, that I'm looking into now. Do any of the results from the live read stand out to you?
P0345, P0335, P0340

 

[rogoman]

I finally had time to run the test using the live data reader. The results are shown on the image. It's also pulling up the following codes, that I'm looking into now. Do any of the results from the live read stand out to you?
P0345, P0335, P0340

The P0345, P0335, P0340 codes point to a problem with the cam shaft position sensors and the crank shaft position sensor. Possible causes:

• - Weak battery.
• - Bad crankshaft position sensor or bad camshaft position sensors. When replacing sensors, always use Nissan OEM parts from a Nissan dealer; aftermarket electronic items generally are not reliable, don't last long, and many times are DOA. Inspect the harness connectors on all the sensors for any oxidation or loose connections; circuit may be open or shorted. Insure that any water resistant connector is in good condition; if the seals have been compromised, then any water intrusion can cause intermittent problems.

 

[Chaoscoordinator]

The P0345, P0335, P0340 codes point to a problem with the cam shaft position sensors and the crank shaft position sensor. Possible causes:

• - Weak battery.
• - Bad crankshaft position sensor or bad camshaft position sensors. When replacing sensors, always use Nissan OEM parts from a Nissan dealer; aftermarket electronic items generally are not reliable, don't last long, and many times are DOA. Inspect the harness connectors on all the sensors for any oxidation or loose connections; circuit may be open or shorted. Insure that any water resistant connector is in good condition; if the seals have been compromised, then any water intrusion can cause intermittent problems.

Thank you, for your reply. Prior to running the code test I've already installed 2 new cam shaft position sensors and installed new crank shaft position sensor. This weekend I plan on checking the sensors recently installed, make sure there are no problems. These sensors were purchased at O'Reilly's (supposed to be OEM). Other than this being an option does any codes pulled from the Live Data mean anything to you that can be helpful?

 

[rogoman]

2004 Nissan Pathfinder
286k miles


Other things I've done to solve the issue:

• installed spark plug anti foulers connectors (drilled out 1/2")
• extended rear o2 sensors

/QUOTE]Why did you add these two mods? Maybe they are creating your problem.

 

[Oldcivicjoe]

The intake air temp reading is well above the coolant temp reading, was this on a cold start when it was very hot outside? Id be looking for corrosion on those sensors and their connectors. The iat is likely built into the map sensor.

 

[VStar650CL]

The intake air temp reading is well above the coolant temp reading, was this on a cold start when it was very hot outside? Id be looking for corrosion on those sensors and their connectors. The iat is likely built into the map sensor.

Yep, the IAT on an '04 is definitely built into the MAF (I assume MAP is a typo, very few Nissans after '00 have one). However, the IAT is a "balance" circuit that reads higher voltage at lower temperature, so any sort of corrosion or open circuit will make it read Alaska and not Miami. The same is true of the ECT. I think your assumption about a cold start on a hot day is probably right, that doesn't look like a sensor issue.

 

[Oldcivicjoe]

Yes, auto correct got me, maf to map, lol.