I drove it home one night (was running fine) and the next day it wouldn't start. With the key on and engine off I could hear the pump run continually. ( I know it's supposed to shut off after a few seconds). I found that if I spray starting fluid or gas into the air intake it will start but if I open the throttle too quickly it will balk and when I let off it's fine.
Since then I changed the hp fuel pump, changed the filter, hooked the iac back up and still nothing changed. Went in the house for maybe 15 min. , came back out and this time turned the key on and heard the pump run , build pressure and shut off. I started the engine and it idled fast for a few seconds , surged op and down a few times, and then settled down to a nice idle speed.
This morning It's 40deg. out and no start , fp runs all the time key is on.
Any Ideas?

 

It should have a Fuel Injection Pressure Regulator on the rear of the fuel rail that might of failed. Check for gas smell in the engine oil or lack off fuel pressure in the fuel rail?

 

The fpr at the rear looks easy enough to replace, Is there any other regulator ? I can't see in the .front

 

If that's the problem....it's not cheap! It does have a Vacuum line on it that might be damaged or loose..

 

When the FPR diaphragm fails the vac line can pull gas into the Intake and flood the rear cylinders. It can hydro lock the engine or blow up!

 

The fuel return line.... I can't see where it hooks up to.... is there a valve on the fuel rail where it hooks up ?

 

Could the fuel just be returning to the tank and not build up pressure?

 

Pretty sure that is not happening, and the Vac line looks OK

 

Things get real messy with fuel and Vapor return lines, I think the only valve on the fuel rail is for pressure relief and used to check pressure.

 

OK so today I got it to run by spraying gas into the intake. Ran it till it got warm and shut it off. Turned the key back on and the pump still ran continuously , but engine starts ... still the same balk when I open the throttle too fast.
Waited 15 min. And tried it again key on engine off, pump runs, builds pressure and shuts off. I start engine and it runs fine , no balk .
The heat seems to be doing something , not right away, but after a few minutes of sitting not running

 

That "Balk" your talking about it telling you it's running Lean.

Sucking in air, and the fuel is not responding quick enough.

Try switching or replacing the fuel pump relay, in the power control box up front, under the hood, under the power brake booster.

When you say the pump is running continually, the relay might be sticking closed, and when you have a no start, the relay is not closing.
And, yes, that could be caused by running it, relay heats up, and when you let it sit, relay cools down, and acts normal.

And, if you can, get a fuel pressure tester on the fuel rail to see what the pump is doing, both key on, and running, that will help with your trouble shooting.

 

I thought that the fuel line that hooks up near the FPR was the pressure line from the pump, but I have learned that one is the RETURN to the tank. So now I'm thinking that the FPR may not be sealing and thus letting the fuel return to the tank. Today I plan on using a hair dryer to heat the FPR a little , see if that helps.