10 minutes ago, Patcon said:

Who cruises at 5,000 rpm's?

Pressure and flow are different!!!!! Pressure is not the issue!!!! The water going over Niagara falls has low pressure but lot's of flow...

If you are running out of fuel it's a flow issue not pressure!

Ok its flow issue. How do i solve this issue? I dont see any kinks on any of the hoses.

Run the flow test out of the FSM!

If it fails, then eliminate the throttle points one by one...

How??? Putting the hose that is attached to the fuel filter in a glass bottle?

Looks like that pump has a built in filter.

 

High RPM weakness is either not enough fuel flow or your ignition failing.

 @jalexquijano I've experienced lack of fuel in my Z. It had a partially blocked fuel filter at the time. There wasn't any cutting out, missing, spitting etc. It just wouldn't go any faster than 45 mph no matter what gear it was in. It would free rev to 6000 rpms but under power, in any gear, just 45 mph.

 The only time I've experienced high rpm misfire in mine, it turned out to be ignition related. I changed spark plugs and the misfire went away. Try installing a new set of plugs and see if it improves. I'd still like to see a pic of all six plugs.

I have a pertronix ignition coil with ignitor module. Could it be failing in some way?

14 minutes ago, Mark Maras said:

 @jalexquijano I've experienced lack of fuel in my Z. It had a partially blocked fuel filter at the time. There wasn't any cutting out, missing, spitting etc. It just wouldn't go any faster than 45 mph no matter what gear it was in. It would free rev to 6000 rpms but under power, in any gear, just 45 mph.

 The only time I've experienced high rpm misfire in mine, it turned out to be ignition related. I changed spark plugs and the misfire went away. Try installing a new set of plugs and see if it improves. I'd still like to see a pic of all six plugs.

What about cleaning all 6 spark plugs with brass brush?

Please post a photo of the plugs as they are now.

@jalexquijano Don't clean the plugs. Take a pic and post it. You could clean the plugs (after the pic) but if the mis-fire continues, you still won't know if it's caused by the plugs. Bite the bullet and buy new plugs.

11 hours ago, jalexquijano said:

How??? Putting the hose that is attached to the fuel filter in a glass bottle?

According to the FSM, fuel pressure can be in the range of 3.41 to 4.27 psi.  More, or less, will cause less than optimal operation.  Your pressure seems to be within range.  Fuel capacity is another issue.  Use a big glass bottle, or a gas can, as the catch basin when you disconnect the fuel line.  Delivery should be 1600 cc (3 3/8 quarts) per minute (static test). 

Dennis

2 hours ago, Mark Maras said:

@jalexquijano Don't clean the plugs. Take a pic and post it. You could clean the plugs (after the pic) but if the mis-fire continues, you still won't know if it's caused by the plugs. Bite the bullet and buy new plugs.

Took the car to the highway and race it at 110 miles per hour according to the speedometer. Some coughing or spitting at the beginnig during the first few minutes and then it cleared up. Really weird. Here are pics of the plugs in the following order : 6 5 4 3 2 1 after racing it

 

your plugs look nicer than mine ever do!