Intermittent Code 12 - RPM Signal - with loss of power

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Jul 19, 2018
Houston, TX
Hi all,

I recently had starting issues that I diagnosed as a crusty connector from the park/neutral position switch. The connector would not separate so I ended up having to cut it out and just solder the wires together.

Starts great now, but now it has a loss of power problem. Driving along and RPMs drop and cannot accelerate. During the brief power loss, it will flash a CEL which I have determined to be Code 12 - RPM signal.


Is this related to the park/neutral switch I just fooled with? I replaced the distributor a while ago with no issues. Just wondering where I should start my search.

The problem is it's intermittent. Happens every 5 minutes or so of driving and then goes away. So it may be hard to diagnose.

Other (maybe related) issues:
-idles high (~1100 RPM) in park and neutral. I think this is because I did a bunch of work on the intake chasing a Code 25/26 and never adjusted the 3 cables (throttle, transmission kick down, cruise) correctly.
-sometimes starts in 3rd gear. I've replaced the transmission solenoids with no change. sluggish when first put into drive -
Last edited:
I decided to pump smoke in the intake to see if there were any leaks. There is a leak that seems to come from the EGR vacuum modulator itself. I don't know if this is related to my Code 12, but is there a way to delete it? My Land Cruiser is not inspected for emissions.

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