also strange that an unplugged MAF does not affect the pulsing idle and stalling symptom either. I'm guessing that eventually I will get another P0300 code, let me know if you think of any other things to check.
(no on the leak down test)

Thanks!!

 

There is a rubber plug on the intake manifold looking down to the right side (drivers) of the throttle body it might be cracked and deteriorating

 

That's too low for fuel pressure. At first start, a cold pump is probably creating more pressure. As the pump warms up, the pressure may be dropping due to an almost worn out pump.

 

The rubber cap is good and sealed

 

My pressure gauge is old (like me) I will re-test it with a better gauge, but if it was a weak fuel pump wouldn't it have even more sputters and problems at higher RPMs? the car runs and drives like a boss as long as it's not sitting at a stop light.......

 

could this vehicle have a bad TPS? or throttle body motor? without logging a code?

 

One of the links in the diagnostic tree does refer to the TPS and refer you to go to P0106. So, I guess so, but the TPS has it's own set of DTCs.

The TPS is not a separate part the entire Throttle body needs replacing. Shop around you can get them for a lot less than MSRP.

 

I went to Autozone and used their fuel pressure gauge and the fuel pressure is just below 60 psi when idling and stays steady when reved.

are there any other things I can try?

 

As far as timing goes, most of the worn timing sets here have been preceded by noise(chatter). Is your engine quiet or noisy? You may be able to pull just the valve cover and see how much slop is in the chain.

You should be able to get a loaner compression tester from your local auto parts store(autozone, etc). Depending on the results of a compression test, you may need to get a leak down tester also. These suggestions(and several others) were made to you earlier in the thread. Not being snarky, but maybe you should read it again.

I wonder if a vacuum leak would cause these symptoms, without throwing other codes? Oldblue, is that what you were getting at when you suggested checking the rubber plug?

 

Yep!