djmarch

iTrader: (4)

No fuel pressure, but hear fuel pump run. Last fall, out of the blue my GTA would not start. Turn the key and the engine would fire then nothing..crank, crank, and crank...No fire. So during the warm days during the winter I tore the top end down. Cleaned the fuel rail, added new O-rings and inspected the diaghram on the fuel regulator. All was good. Put top end back together today and added a hard line fuel pressure 0-60 liquid filled gage....Yes I removed the needle from the shrader valve. Went to start with same issue. Funny thing is I have no pressure at the gage, but yet when I cracked the fuel line at the frame rail, I had pressure and fuel. A lot..Cranked the screw on the fuel regulator all the down and still no pressure reading.

What am I missing here ?

Ozz1967

iTrader: (4)

Did you verify pressure with a gauge?

Sometimes when a fuel pump goes bad, it'll have enough power left to prime the line but not feed the motor. With zero pressure at the rail, I'd start there after verifying you have 12V on the line going to the pump.

djmarch

iTrader: (4)

I have no pressure at all with a gauge at the rail like I mention, unless you're referring to taking pressure somewhere else. I hear the fuel pump run when turning the ignition, which tells me it's getting power. What pisses me off is I put a new AC Delco fuel pump in 2 years ago and it doesn't have 500 miles on it. As you stated, that's the only other thing that I can think of is the fuel pump. I'm going to search this site for a cutting an access hole because the first time was a pain in the butt even without the st.st catback exhaust system I put in after.

Ozz1967

iTrader: (4)

If you can hear the pump turn on but have no pressure at the rail, that means the pump is bad or the line is clogged. Some last 100K miles and more, some last less than 1000. It's electronics...*Voodoo magic* if you will.

djmarch

iTrader: (4)

Thanks for your input Ozz...Yes...After considerable thought, it has to be the pump as you stated. I cleaned and applied air to all tubes in the fuel rail when I replaced all the O-rings, so being clogged is out. I'm going to tackle the fuel pump by putting in an access hole. After dropping the fuel tank the first time, I'm not going to go through that again. As an engineer myself, this is one of GM's worst design. Adding an access hole will not effect the integrity of the body. I'll make it look professional. I already have pulled the carpet back and marked where I will cut. I plan on using compression to AN fittings and hose from the steel lines to the bulkhead on the undercarriage.

ETX

I am having a similar issue. My car hard starts. Key on no pressure at the fuel rail. The car will start albeit hard once it has cranked enough for pressure to be over 40 psi on the rail. Then the car runs and idles great. Just hard starts.

Making matters worse is I just had a vortec long block swapped for the original L98. The car sat the last two years for because it knocked. I put a battery in, start after cranking twice to go to the shop. Since the swap it starts hard.

Is there any way to confirm fuel pump?

Ozz1967

iTrader: (4)

If you have put a fuel pressure gauge on the rail and have zero or low fuel pressure that's your confirmation of a bad pump. I'd say, since it takes time to build up pressure, it's the pump.

If you had initial pressure and 40 PSI on the rail and the car starts, even if it starts hard, and runs, then the pump probably isn't the issue though it could be. Verify 12V at the pump, clean the lines by blowing air through them.

Beyond that, it may be something like timing or an ECM issue.

djmarch

iTrader: (4)

Chapter II
What fuel pumps are you guys using ? I'm very disappointed with AC Delco. There isn't 500 miles on this one I replaced that I'm going to have to replace again, but before I pull the fuel sending unit, I want to check for voltage at the connection, but cant seem to pull the connector off the top of the sending unit without afraid of snapping it off. Is there a trick to this ? There should be 12v with the ignition key on correct ? I've replaced the fuel pump relay with a spare I had, swapped out the ECM with a spare I had as well. It has to be a bad pump even though I hear it run when turn the ignition on.

Ozz1967

iTrader: (4)

I personally have a wahlboro 255lph pump that's been running well the past 5 years.

mk1431

mine was acting up years ago i went with wahloro also mine sits alot no problem with pump

djmarch

iTrader: (4)

That's what I'm going to go with Ozz...In addition, for what its worth, I replaced the OP sensor as well thinking of all possibilities before I tear into the tank.