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97' Losing power under load at 3000rpm

Posted: Thu Dec 22, 2016 2:35 pm
by boomguy
Hello all, I have had an ongoing issue with my Pathfinder losing power from pulling timing under load once the engine hits about 3000rpm. I had a faulty knock sensor which tripped a code so I replaced that the hard way and the code has not shown back up. I've hooked it up to a autel and watched it bump the timing from 30* to 60* as soon as it hits that 3000rpm threshold. I've cleaned the stuffings out of the MAF sensor and have new plugs, wires, distributor cap and rotor. After getting everything back together I now have a P1105 code for the map sensor solenoid which I will be looking into. Any ideas? I'm at a bit of a loss.

Posted: Thu Dec 22, 2016 5:04 pm
by smj999smj
The P1105 code is fairly common on these vehicles. There is a good article on how to test this here:

http://www.checkenginetroublecode.com/p ... ap-sensor/

I have replaced a few of what they describe as the "Baro Sensor" in the article due to sticking (I've always referred to it as the MAP/BARO solenoid valve). I would address this issue first as it can cause sluggish performance/lack of power.

Once that is done, I would check the ignition timing using a timing light. Warm up the engine and make sure the coolant gauge needle is around the middle (if it is too low, you may have a stuck open thermostat). Run the engine between 2000-3000 RPM for about two minutes. Let idle and turn off the engine. Unplug the harness connector on the throttle position sensor and re-start the engine. Rev the engine a few times and let idle. This will put the ECM into timing set mode. Check and adjust the timing, as necessary, with a timing light. Adjust the base idle to spec. Shut off the engine, plug the TPS back in and you're done. Hope this helps.

Posted: Sat Dec 24, 2016 5:10 pm
by boomguy
Thanks for the advice, I'll definitely look into the sensor when I get a chance after the holidays. The thermostat isn't an issue as it warms up quickly and stays consistent with the temp. The fast idle circuit is the only other wonky thing.