My 1988 chevy truck broke down and wont start HEEELP?

[Roy]

My fuel sending unit is broken and I cant tell how much fuel I have. Well I assumed I had about $20 (4-5 gallons) I drove for about 45 minutes to go pick up some tires as soon as i pull onto the guys road My truck cuts off. I assumed it was out of gas. So I took my 2 gallon gas can and poured it in. Started the truck back up, drove 30 ft and she dies again. Sooo I check over everything. Im getting spark and fuel. Fuel is even going back into the tank from the return.

I get it towed home and drop the tank, its completely full. Pump is coming on and pump filter is clean enough. I replaced the inline fuel filter as well. Truck will start for 3 seconds and then cuts off. Only thing left is pressure regulator, right? Well I get the rebuild kit and I open it up and the spring is broken, Shew, I found the problem....repair it and now it wont start at all. WHAAAT IN THE WORLD

The Good:
Cranks normally
getting fuel-pump less than 10k, replaced filter and regulator. Injectors are working
it IS getting spark-All ignition parts replaced less than 10k miles ago
new air filter

The Bad:
Just wont start
Ive had the truck about 6 months and its always had to turn over for 6 seconds before firing up
She has always started of slow and runs great when warmed up.

Any one had a similar problem?
Thanks for the fast response, mailbox1024.

My oil level is full and Im getting fuel up front and its coming out of the injectors. When I turn the key, the pump can be heard from in the cab (normal). If Im getting fuel could I still have a problem with the relay and oil pressure switch?

Im gonna repair the sending unit before I put the tank back. I hate not know how much fuel I have.

Its also a 4.3 liter v6 with a 5 speed trans 2wd c1500

 

[mailbox1024]

Try replacing the fuel pump relay, this will cause your extended crank before starting. Also the oil pressure switch is your fail safe system, if defective, it will cut off power to the fuel pump, it is designed to work this way in the event that you are low on oil and it will cut power to the pump and not allow you to seize the engine. Now that you dropped your gas tank, this would be a good time to replace the sending unit because if you run the tank out of gas, the electric fuel pump gets exposed to air and can burn out the fuel pump. 1/2 the job is done by dropping the tank so complete the job and fix 1/2 the problems.
good luck..