99 4-runner low idle help needed

[BioTex]

If you could borrow a fuel pressure gauge and tap into the fuel rail,check your base fuel pressure and shut off engine rule of thumb is you can only loose about 5-10 psi with in 10-15 min and if you let it sit overnight you should still see a residual pressure around 20 psi. you may have some issue with how fast your pump is pumping fuel when the pressure drops you also need to check fuel volume even if your pressure is good but not enough volume your system could starve for fuel.

Will do. I can't see where to hook up a gauge, and to confirm before I purchase the wrong thing, is it a banjo style connection?

Edit: After searching, I found a banjo to SAE american style adapter so I will be able to hook up my pressure gauge. I ordered it and will have it soon. Will finally possibly get to the bottom of this issue.

 

[BioTex]

I had removed and cleaned both the IAC and the throttle body a couple of days ago. I was waiting for the new gasket to show up, and last night it did. I applied voltage to the IAC to verify it opens and closes as it should. I reassembled everything with the new gasket and much to my surprise the engine fired up on the first crank. I let the engine idle for 5 seconds and shut it down. Tried to restart and it was very long cranking just as before. I cycled the key several times but still wouldn't start until finally it did. very rough idle until it warmed up some. Then after warm it started idling low again. Around 450 rpms i'd guess by looking at the tach.

Now since I now have the dash command and wifi obd2 program, I hooked it up to see what the computer said the rpms were. It showed around 700 - 730 rpm. Timing looks good at +8° to +10° and climbs normally when you gain rpm. Intake coolant temp was 64°F and climbed to around 85° as things warmed up. O2 sensor read .2 - .7V and the MAF read .6 lb/min. Load = 23%

What do you guys think?
My gauge hookup should arrive soon so I can get those fuel pressure readings.
No codes showing.

 

[BioTex]

Can someone tell me what sensor gives the computer the tach signal please? Is it the CPS? This is the olnly thing I can think of that would cause the computer to show the engine is idling at 750 when in fact it is only 500 or less.

Could this also be the cause of my hard starts when cold?

 

[BioTex]

I think I found the problem. #3 cylinder has only 70# compression. I verified the exhaust valves are the reason. Looks like I'm pulling the head soon.

 

[BioTex]

Update:
I pulled the head and removed the exhaust valves. One of the #3 cylinder valves is burnt so you can see it with the eye.
I'm replacing all of them with new. The seats are good and the head is not warped. Looks like I'll be doing the valve job myself.