Had about 1/8 of a tank left and went to the gas station to fill up. Filled her up and then no start. She ran fine all day/week. At first all she did was crank and wouldn't turn over like she had a bad ICM. A few mins later she started and ran for about 5 secs really rough and died again. This happened about 5 more times and now wont turn over at all. Just keeps cranking. So I pulled the ICM and walked to Autozone across the street from the gas station. ICM tested fine. I reinstalled it and still nothing. I had to have my friend tow me home from the gas station with his F-250. It was a sad day. Scanned for codes when I got home and there wasn't any. Now I'm wondering if its the fuel pump, or the opti. The opti only has about 6k miles on it (brand new GM). Now the fuel pump is original and has 157k on it. I don't hear the pump prime when I turn the key to run. I've searched and have narrowed it down to those 2 culprits. If anyone else has any other ideas I'd really appreciate it. I'm stuck at work for the next 24hrs so I can't test anything cause the car is at home. If everyone thinks it's the fuel pump I'll just order one now so I can get it fast. I just don't get how it could be running fine and then just not start after filling it up?

 

THe first thing to do is to listen for the fuel pump when you turn the key or hit the priming wire.

THe fuel pump on my wire's car failed right after a fuel up. I believe it was becuase she routinely ran the tank very low and the pump overheated. Anyway, check for the sound and if you don't hear it check for voltage at the terminal block near the fuel pump....

 

Try starting the fuel pump by supplying 12V to the fuel pump prime connector near the PCM.

Courtesy of Shoebox

http://shbox.com/1/fuel_pump_prime.jpg

Did you Loc-Tite the Opti rotor screws before you installed it?

 

I did Loc-Tite the opti rotor screws when I installed it. I'll check to see if the fuel pump is priming with the wire and check the block tomorrow morning when I get off work. I don't usually let the fuel tank get that low before a fill up, usually fill up no less than 1/4 of a tank even though it's not really a 1/4. I don't drive the car that much, usually stays in the garage. The sad thing is that a guy at the gas station was talking about how good the car looked when I was filling it up. Then I try to leave and no start.

 

Fuel pump. Seen it way to many times after a fill up. Got me home with a trick from a buddy. Hit the bottom of the tank with a broom stick or other while someone cranks it over.

Of course a gauge will tell you what the deal is. If like us, you're out on the road and don't have a gauge with you. Relieve the pressure at the schrader valve. Then cycle the key several times on and off then check the valve for pressure but watch your eyes.

 

So the car started right up this morning. I could hear the pump prime when the key was in the on position but it sounded very weak kinda like it was struggling. I let it idle for a little bit, shut it down and it started again. Did this 4 times. Then I tried to start the fuel pump by supplying 12V to the fuel pump prime connector. There was no noise, just quiet. Pulled the wire, tried to start it and it did the same thing as yesterday. Wouldn't turn over. Glad I didn't go on a test drive. So I'm going to replace it with a kit from racetronix and do the trap door method. What kit should I order? Should I get the harness body ground upgrade? Should I get the PBIC pump booster connector set just in case I decide to upgrade later down the road? Let me know. Plan on ordering today. Thanks for everyone's help.

 

If its a great car, do the fuel pump right!! I check every fbody for that before I buy it. If you do cut it open, round out the corners. 90* angles can crack.

 

Fyi tin snips will cut the sheet metal and not throw sparks and leave filings(once its opened up enough) I chose to cut three sides open and fold the flap up. Once im satisfied with everything will seal it up with marine adhesive(very good sealant). I chose the racetronix with the hotwire.

 

Make sure it's not a problem with corrosion on the rear harness connector or the ground,

Courtesy of Shoebox

http://shbox.com/1/fuel_pump_wiring.jpg

 

Id check that too^^^^ even if you already ordered a pump. Another note the racetronix pump with hotwire will potentially increase your fuel pressure 4-5 psi with stock regulator and may effect your tune a bit. Would be wise to check your fuel pressure if your existing pump just has bad ground or connection once repaired or once pump is replaced. Im not sure how much the pcm or your existing tune would allow from its set perameter. In case you dont have a pressure tester you can borrow from autozone or orieleys with about $100 deposit. When I tested mine it was touchy as if I tightened too much by hand on the connection to the schrader valve I wouldnt get a reading so I had to find the sweet spot. I even had it partially reading so might have to play with the connection a bit to be certain your pleased with the reading.