ECT is coolant temperature sensor. It's located near the upper radiator hose outlet at the front of the motor.

Does the truck start and run if you unplug the MAP sensor's electrical connection?

 

I haven't disconnected the MAP yet but I will tomorrow.

Oh! I was talking to my old man about this the other day and he had me jump the ECT.

 

The truck started with the MAP disconnected.

It didn't run for long and while the map was disconnected I had to give it quick throttle pump until about 1/2 way to get it to start. So I reconnected the map and when I pressed the gas pedal 1/2 quickly while cranking and the truck started.

I turned the truck off and waited about 10 min then I re attempted to start the truck again and it only turned over. I cycled the ignition a could times then it started.

Also I measured the time the fuel pump ran.
From the first click that engages, the pump runs for about 1.2 seconds before cutting out then .5 seconds later there's a second final click.

 

Hopefully replacing it fixes the issue.

 

Why would the MAP be causing the problem?
I know it reads the vacuum and sends a signal to the computer and thats about it.

 

The MAP sensor is primarily responsible for controlling engine fueling.

 

Ill get around to replacing it soon and Ill send an update

 

I got a round to replacing the MAP and the Fuel Relay.
There was no difference in starting with the new MAP and after spraying ether to get it started, there was no difference in running.

I then replaced the relay and boy is it easier to start. I only need to turn the key 1-2 times with the throttle pressed in at 1/2 to 3/4 and she fires up.

While it was running I disconnected the old MAP and there was a change in running. I then disconnected the ATC on the intake and there was another noticeable change. I turned off the truck and disconnected the ECT and there was a quick drop in RPM when right after starting.

 

When unplugging the ECT, the computer defaults to thinking the engine is warm, which will drop the idle RPM. What relay did you replace?

 

I replaced the green fuel pump relay.

So the truck starts when the pedal is pressed in 1/2 -3/4 way now.

 

Can you watch the fuel pressure gauge while somone attempts to start the truck?

 

I'll get that done today hopefully

 

So the fuel pressure when turning the key to on once was 8psi
It took about 4 cycles to get the pump at 36 psi but it held when I got cranked it

After quite a few tries the truck started up and was holding at 30 psi flat
And only went up to 32 psi when floored

 

You either have a bad FPR, bad fuel pump or a plugged fuel filter. I'd start with the filter.

 

Thats funny because everything is brand new. LOL
Ill start with the fuel filter then the pump
The FPR was 70 bucks and the pump is under warrenty