85 TA 305 TPI:
I took out my bird for the first time in months yesterday. It ran fine till I got home, when I noticed after shutting it off that I left my window down.
I turned the key to run position just to roll it up, and noticed I didn't hear the pump trying to run.
I then tried turning it over,(and the pump not running )which took a few times, and it started and stayed running, and the SES light came on. after starting and stopping sevral times, it was the same thing, no initial start pump running .
Today i tried again, the pump DID run at initial start, but after shutting off and re-start, same thing....no pump.
Seems like a fuel pressure switch problem??????
or has my pump finally s**t the bed?????
BTW:
Before the winter I was testing the pump and jumpered the wrong terminals on the Fuel pump relay, possibly shorting my ecm ......cause the pump ran CONSTANTLY in the run position without turning the car over, but it started always. I never let it run more than 5 seconds just to build pressure before starting. Could this be another problem with the ecm that has started ???
I was planning on replacing/repairing the ecm when it got nice out anyway,but I'm not sure if this problem is more than the ecm now.
Any Ideas guys?

 

Check the fuse and fusible link near the battery. It may be a little hard to find, it goes into the wire bundle that runs along the driver side framerail, and it should be an orange wire. That is the fuel pump power wire, as well as the ECM constant power. If the fusible link looks burned, melted, or corroded at all, I would replace it. It took me a week to find out that was the reason my fuel pump wouldn't come on.

Also, you can test the fuel pump by jumpering +12V to the bottom left ALDL pin. This is the fuel pump test pin, it bypasses the fuse/fusible link/oil pressure switch. If you supply 12V there and the fuel pump runs, then chances are that the pump is okay.

 

I don't think you have a problem. Not sure about the SES light. Did you check the code? My 89 TPI pump only runs for 2 seconds when it's first started. It never is supposed to run continuously with the engine off. The ECM needs a signal from the crank sensor OR the oil pressure switch for the fuel pump to remain on. It is also only able to be heard one time when I first start it after the fuel pressure has had time to bleed off. You should not hear the pump prime "buzz" if you keep turning the key from off to on. Only the first time until it gets pressure. So from what you said, your TPI behaves just like my TPI does and my old one and every other GM injected car I've driven. Hope that helps!

 

Sounds like an intermittant FP relay to me. With the relay working it will get fuel pressure immediately. If it's not working, it won't get pressure until you have enough oil pressure to turn it on (there are two circuits in parallel to power the pump).