I am beginning to suspect feul pressure, as the culprit causing hard starting.
Will these engines run with a fuel pump out? Do these pumps fail totally or do they sometimes just run at low pressure?
I've never seen one on a Chevy run low. They just run or don't.

The toyota manual has you pinch check the line for pressure ( not specified how much) in the line when trouble shooting hard starting due to a pump.

I'll go out later and pinch check the fuel line for pressure . It is a 96 3.4l

This might help:
http://www.4crawler.com/4x4/CheapTricks/index.shtml#FuelPump

Our trucks are similar. There is probably a place to jump the fuel pump on our trucks too, but I haven't really looked into it...

I also noticed that when I stop to fill up, there is no Whoosh, when I open the cap.

every car I have had in the last 10 years has some pressure built up. Wonder if that could be affecting it.

Does yours whoosh?

Yup...pressure in the tank help the line pressure...

The pressure in the tank should be negative (vacuum) if you've been driving a while. If not, you may have knocked off a vacuum or EVAP hose somewhere. That would likely make it idle lower and/or poorly, and EVAP system problems also usually set off the check engine light (like when you leave the gas tank cap off).

It does idle a little slow, around 500 to 550 and a bit rough. No CEL or codes, and I notices that sometimes there is a whoosh of vacuum. Is there a valve that could be sticking sometimes, not always?

BTW, anyone ever change the in tank fuel pump on these? How much trouble is it? I could not hear/feel mine running yesterday with the key on, engine off.

Key on/engine off, pump should not be running. That's why there should be a way to jumper it on to test it, similar to what is shown in the link I posted.

The IAC (idle air control) valve can get sticky. Cleaning the throttle body with some throttle body cleaner usually helps with that.

Another cause for intermittent idle problems sometimes is cracked rubber intake air tube connectors. Those can be tough to find/troubleshoot sometimes.

A good way to check that is take a small propane torch, unlit, and open the valve slightly and wave it all around that intake tube. Idle will change if it sucks in the propane through a leak. My T has alway idled around 550 since I bought it w/60K on it. I would think low fuel pressure would be more evident at high RPMs when it really needs the fuel. It is possible the pressure in the line is bleeding off between starts but that should go away once it has started and pressure comes back up. There is a pressure regulator in the system that also keeps it charged. Could be leaking.

My T100 has also had some problems starting during the past 6-7 months. When it is warm out and the truck has sat for a few hours in the afternoon sun it takes a lot longer while cranking to start.

I had two ideas about what is causing this. One, the fuel pump is not strong enough to build the pressure required for starting (something that happens to some toyotas per my instructor). Two, the fuel pressure regulator is faulty. My understanding of the pressure regulator is that it bleeds off pressure when the pressure is too high. I did not think that it maintained a minimum pressure.

Both of my kraut wagens have lost tank vacuum. The 97 is OBD2 and its CEL lights up. The 95 is not and the car does not care. I don't know if the 96 T is OBD2 but if it is, it's required to test the EVAP for leaks by applying pressure, closing the vent and monitoring for pressure loss after 100 seconds. If your truck is OBD2 and there is no engine light, then the vacuum loss is very slow over time. (My 97 car is TLEV and this may cause it to be more picky.)

The only part of EVAP that is connected to manifold vacuum is the purge line. (Carbon box to valve at manifold)

The actual benefits of EVAP system are negligible but it is required to be working properly to pass some emissions inspections.

Like I said in the other thread I have not had to dig into this engine for troubleshooting but I think I would look at vacuum trouble as this can be inspected without touching the fuel lines and special equipment. You can just remove one of the hoses on the intake manifold and see if the idle changes. Vac leaks can come up in the strangest places, if you cannot find any leaking hoses, it could be a gasket somewhere on the engine (oil leaks are vacuum leaks too!)