Denroll

That's the deal. Checking the Dashdaq, everything looks normal at the beginning. Then after about 20 seconds, the AFR starts going up and up with the STFTs chasing it, trying to compensate, then it sputters and dies like it ran out of fuel. I can turn the ignition off and then back on and it will start up again just fine, then it will die out again.

I'm sure this is a simple fix, but just hoping one of you all have experienced this so I can zero in on it quickly. I had the car apart doing a lot of work. I replaced the fuel pump assembly (passenger side) and had the supercharger/fuel rail off. I'm about 90% sure it has something to do with inside the tank. There's no lumpy/rough idle like it's an injector or coil pack.

Fuel pumps... there is the one hose per pump that clips on firmly, then there is the fat hose coming from the sender that clips on to the assembly, and then there was one more normal sized hose that was just kinda there, pointing down into one of the baskets. The float sensor was connected. Anything I could have missed?

SICAMG

Do you have a fuel pressure gauge in it or inline that you can watch?

Denroll

No, but the pumps are brand new and the fuel sender isn't very old.

jmb614

Did you check the voltages on your primary O2 sensors? Are they lazy or stuck?

shardul

iTrader: (1)

check fuel pressure at the rail

Denroll

I've got the looped rail and that port is removed. No easy way for me to check.

Denroll

Here's what it looks like in the tank. That loose hose... Does it go anywhere? It was kinda like that when I pulled the old assembly out.

Denroll

When I start it, it's like the pumps squirt an initial amount of fuel and then they stop. I tried giving it a little throttle and raised the revs to just under 2k rpm, and this accelerates the stalling process. After it stalled, I immediately tried starting it and it started up just fine, then did the same thing.

hayseed

iTrader: (2)

Almost seems like it's got an air bubble or vapor lock in the fuel line somewhere... Runs long enough for the fuel in the line to run out then die

mufc

I just had my fuel pumps and tank replaced at the dealer and had a similar problem. Turned out the fuel line that pumps gas from one side of the tank to the other was installed improperly and had kinked causing the start / stop situation. I had no fuel pressure after a few seconds. This will only happen if your tank is 1/2 full or less. My gas gauge read one or two notches under half a tank. If yours fuel level is similar it is worth checking. Add a few gallons to the tank and if the problem goes away, you will know that could be the cause. Hope this helps

Denroll

Mine is low enough that the gas light is on. How did they fix that?

E55Freak

So instead of keeping gas below 3/4 you now have to keep it above!

Denroll

Here's a video of the pumps in action. They prime themselves with ignition in position 2, fuel is getting pumped over from the sender on the driver's side when the engine turns on, then... nothing.

SICAMG

With your car as modded as it is...or any car for that matter, you really should pull that fuel rail,install a center inlet/inline filter and use an adapter for a fuel pressure gauge.{I also took the factory filter in the tank out of the housing as well} Thats what I did when I looped mine so if you think you have a fuel problem, just look at the gauge and you will know right away. Of course fix this problem you have first before you go down that road of taking things apart. Hope you get it sorted. Still sounds like a fuel problem.

Denroll

I unplugged one of the pumps just to see what would happen, but it made zero difference.

I might try swapping the old pumps back in to see if the problem persists.

sexyxe

Sounds truely crap! I'm not far from doing my pumps and filter too.

ajm55

Dennis, I experienced the identical symptoms when I was trying to resolve my fuel pressure issue a while ago. I was measuring fuel pressure via the DashDAQ and in my case a sharp drop in fuel pressure would cause the engine to stutter and cut out in the same way you've described.
Don't know if this will help but to the best of my recollection, we'd just replaced the Aeromotives with AEM pumps and an installation error was causing fuel to be drained from the side of the tank which houses the pumps to the side that houses the filter thus starving the pumps and killing the FP. Have you checked whether there's fuel in the fuel pump side of the tank when the car cuts out?

Denroll

Yes, there is enough fuel in the pump side. In the video, you can see that the fuel pump baskets are getting filled up. It's just like the pumps turn off after start up.

ajm55

Sorry I see the video now.

Are you sure that haven't swapped the wiring from the primary pump with the wiring from the secondary pump?

Edit: On second thoughts, that probably wouldn't result in the symptoms you're seeing

Denroll

I tried that, too.

hayseed

iTrader: (2)

fuel pressure sensor ? sorry just throwing part at you but don't know how to diagnose without putting a meter somewhere in line --


http://www.partsgeek.com/gbproducts/...FRCMaQodg5QAhw

chawkins2001

My car did the exact same thing, it turned out my fuel line had pulled loose. That was instance number one.

Instance number two was when I was on e85, I started going through pumps like crazy. When my one pump went, it did exactly what you are describing. Is she throwing any codes, if not that is a sure sign lack of fuel delivery and one of your pumps is faulty.

Can you pull the pumps and put power to them so see if they are both working?

Denroll

Did your fuel line pull loose from the pump or from somewhere else?

I checked as best I could to see if the lines were kinked or twisted, but it doesn't feel like it.

AgSilver

The loose hose needs to be placed in right side of the tank. It does nor connect to anything. This is the discharge from the internal bypass from the pressure regulator in the filter assembly. As the left side of the tank drains, the bypass hose insures that the sump on the right side of the tank where the pumps are located always has fuel.

Denroll

Ok, rad. That one was messing with my mind. That, and the gas fumes.