Not sure what to do next!

PLEASE HELP!!!
My 99 2.7 Tacoma won't start. When I first got the truck less than a year ago, I had some re-starting issues. That is to say, cold starts were no problem-after operating temp was reached stopping and starting became difficult. I have been trying to figure out the codes the system is putting up 300-302 and 440. I have a list of things that these codes could involve. To date, I have replaced:
Fuel filter
Starter
Fuel cap
Vsv for vapor pressure sensor
EGR valve
Coolant temp sensor
MAF/IAT sensor(2 in 1)
Plugs and wires
Cam pos sensor
Idle control valve
I have cleaned the injectors, cleaned throttle body, compression on first cylinder is 178 at 250 rpm. I'm stuck! Truck still won't start. It wants to, but has low choppy idle then dies. This is my daily driver and has been great! Please help!

 

Fuel pump?

 

Timing jumped or fuel pump. Mis-read that at first

 

Fuel seems to be delivered just fine. Timing belt was a nightmare I didn't want to face,but seems plausible. Sux!

 

OK Google!

 

If you have fuel, fire and air it's probably a timing issue

 

Any tips tricks or cheat codes for this would be helpful! Hate to have to pull the engine!

 

After doing research I find out that my particular engine has no timing belt it has a timing chain that should never need to be changed so I don't think my timing is issue maybe I do need to go to the fuel pump

 

One thing I guess I should add as I do have an exhaust leak when I bought it I was told that the exhaust manifold gasket is already started leaking it has gotten worse since I've owned the vehicle I have a replacement manifold because the previous owner got one when they heard it's common for them to crack. I find it hard to believe that this has anything to do with a starting issue but any input would be great

 

Possibly , But a timing issue could be caused by the cam gears jumping(advancing) tooth on the chain.

 

It is a single overhead cam so you talkin the same possibility with only one cam gear?

 

Not true. About never needing changing. They do wear out. And you don't tell us the mileage on the vehicle, which is a little bit of a clue.

Not common, but does / can happen.

Pretty sure it's DOHC

 

Definitely make sure the fuel pump is working properly

 

Could this simpl

112000, sorry

 

Seems a narrow head to be dual cam? I haven't broke into it yet, but I've rebuilt one before.

 

Sorry I overdid the pics. I'm old school, need a grandchild to do this for me

 

Four valves per cylinder and DOHC. "As to the timing chain, the main chain has a mechanical ratchet adjuster, the balance shafts have a hydraulic adjuster. The mechanical adjuster sometimes gets carbon gunk buildup on the teeth of the ratchet mechanism preventing it from staying clicked to the next tooth. A "motor flush" will solve this by cleaning all the gunk out of the oil system. It will also clean all the gunk out of the oil control rings in the pistons, and the little holes behind them. EVERY engine I have torn down without a motor flush all these little holes were plugged up."

Pull the valve cover and see if the alignment marks are lined up after you've eliminated the easier fixes through diagnostics.

 

That's a DOHC engine..... e3rz-73