I waited a week for Autozone to get me the right fuel pump. Spent $280 on the supposedly superior Delphi, and wouldn't you know it doesn't do any better than my old worn out one?
I have low fuel pressure (30ish PSI) and it won't stay primed after shutoff. Looked at the plugs, they're all a bit ashy and lean. So I put in a new fuel pressure regulator. No effect. Put in the brand new Delphi pump, whole apparatus with lines and sending unit and everything, and it still has low pressure and it still bleeds to 0 right after shutoff, but slightly slower now, so yippee.
You can't get anything good from the parts store these days. If they're going to keep making pumps and charge these prices for them, they could at least make ones that don't leak pressure. Unless I'm missing something and there's another possible cause, but I can't imagine.

 

What here is this thing?

 

If I'm not making sense, you have my blessing to get rid of the thread. I'm receptive to the notion that I am making up problems, after sleeping on it.

 

No, what year and model is your car?
If it's not in the title and it's not in the post, I'm not going to look it up from an old post.

It sucks that the mobile version of this site does not display signatures.

But it is what it is.

 

97 SW1.

Is it a returnless fuel system or does it have a return line?

How is he was the regulator to install the clip over? If you have any trouble at all, the o-ring at the bottom for the last fuel regulator is probably still in there. It's very hard to see and very easy to drop and lose. You can jam two of them in there successfully, but having done so, I don't recommend it. That could be one place where you have a pressure drop/leak.

Unlike the later s cars, yours that does not have a fuel pressure regulator inside the fuel filter. Your fuel filter maybe damaged or clogged.

I suppose The fuel pump could have a bad check valve.

If you value your sanity, don't purchase important or electrical parts from the chain stores. Rockauto.com, GM partsgiant.com, etc. Yes I know most of the OEM parts are not available anymore, but some of them are.

Are you measuring fuel pressure at the rail? If so with what?

 

Apologies. I'll be more clear in the future.

It has a return line. I was pretty gentle with the fuel pressure regulator when I put it in, and I'm certain I don't have too many o-rings in there because I dropped the new one and lost it. Clip went on nicely. I thought about the fuel filter, but the pressure primes up so fast when I turn the key on, it doesn't seem restricted. It might be a good idea to swap it anyway. I was measuring pressure with the loaner gauge you get from Autozone, at the Schrader valve near the rail. I think I was the first person to use it. I don't doubt its reading.

Upon further review of the service manual, it seems like 30 PSI isn't actually that bad. But I still think it shouldn't lose pressure in a matter of seconds. The cylinders are dry so it's not the injectors.

I have never tried Rockauto before. They do have a selection of other fuel pumps I might have been better off with, so if nothing else I learned that.

Edit: unplugged the return line to see what was getting through. How much fuel is supposed to get past the fuel pressure regulator with key on, engine off? Is it a lot? Because I'm getting a lot.

Edit Edit: AutoZone did me dirty once again. Thank God I kept the old regulator.