OK, I have to ask this question since I've cleaned everything.

Here's the deal. I start the engine and it will idle just fine. BUT, when I use the pedal to add RPM's to a consistant RPM(example 1200 RPM's to warm it up and hold). I can watch the RPM's pulse between 1200 and 1225-1250 without moving my foot. Anyone have an idea on that? I've used a multimeter to try and locate any electrical variations with no luck.

And the engine is completely fine when driving it. Its just that symptom.

 

If you're using the pedal to increase the rpms, thats not an idle issue! As soon as the TPS reads that the throttle body has been opened, it no longer tells the IAC to idle the engine.

My gut instinct says its just the tachometer. They aren't the most accurate tachometers out there. If it really is the engine pulsing and not just the tach, then it could be the TPS, MAP, etc. Its hard to say with all the inputs the computer needs to run the engine.

But if thats the only issue you have with your truck, I would say don't even worry about it!

 

I don't really worry about it. You can hear it in the engine. You think it could be the pressure regulator? Other than that, I really have no problems with the engine at all. It runs top notch. I also noticed the PCV lets oil vapor into the engine and I made a catch can to eliminate actual oil into the intake. So Ill see if over time that cleans things up.

 

I bet its just minor irregularities in the TPS and/or MAP sensors. There may not even be anything wrong with either sensor, just sending out a varying signal. Keep in mind that the computer relies on the sensors to know how much fuel to inject, so any variations in the signals jumping around would cause it to inject more or less each time around. That, and its hard to hold your foot completely steady. I bet if you put a voltmeter on the TPS and MAP and held the throttle open with your hand you would see the signal jumping.

 

Its a good possibility that the map sensor is fowled with the engine running. I'm gonna try replacing that. I don't get that on the ZJ cause the MAP is mounted to the fire wall.