if i jumper the yellow connector in the engine bay to make the fuel pump run in the run position of the ignition switch does it mean that the fuel pump is working optimally if i put my hand on the top of the tank through the hole in the floor of the hatch and i feel a slight constant vibration but i don't hear anything? i checked the connector to the pump with a multimeter in the run position of the ignition switch. one was 12v, one was 0v, and two were around 6v. is that right?

 

The large gauge BLUE wire on the chassis harness side of the fuel pump connector is for the fuel pump. ON the other side of the connector the color changes to black/white. The other wires are for the gauge etc.

Got fuel in the tank?

With the key to on and the plug jumpered, crack one of the banjo bolts on the secondary fuel rail and see if it sparys fuel. You can do this on a S4, I don't know about a S5. Semi not a safe practice.

 

i have plenty of fuel in the tank. do those voltages sound right? i didn't look at the colors until i had put away the multimeter so i didn't bother to put voltages with colored wires. I don't think my fuel pump is completely screwed...i think that maybe it's not pushing strong enough to keep up fuel pressure. basically, i changed my fuel filter, i broke down, i changed the alternator, battery, ignition coils, and starter, and it still won't start so i think that it may be the fuel pump. if it's not that and i try to change out the MAF and that doesn't work, i'm just going to bring it to a rotary shop and have them figure it out.

 

should be a 12 volts and ground for the pump power , then the 6 volt ones u see are for the level sender, and low fuel light

 

cool. so is it possible that the pump isn't running at full efficiency therefore not building up enough fuel pressure due to a fuel filter replacement?

p.s. the filter had some rust on the nipple on each side and it probably had not been changed out for a long time.

 

No. Don't start changing parts out. Jumper the fuel pump check connector and then loosen one of the banjo bolts on the secondary fuel rail. Fuel should spray. You can just retighten the bolt once it starts spraying. Not a big deal.

Or you could pull the fuel line off the fuel line that feeds the motor. It's the one that comes from the filter. Leave the jumper out. Turn the key to ON. Put the fuel hose in a container then put the jumper in. Fuel should flow into the container. If it does, the fuel pump is probably good.

Engine is probably flooded. Leave the fuel pump connector off. Start the car. IF it starts for a moment, then put the connector back on the pump and try again. Repeat the process if required.

 

i've tried several times to unflood it many different ways in the 2 months my car has been down to no avail. haven't tried the pump connector, but i've tried the egi fuse, holding pedal down, pulling plugs, etc. do you really think disconnecting the pump connector will work?

 

Well, I see you have a S5. Holding the pedal to the floor is supposed to disable the fuel pump while turning the engine over. Sooooo I guess pulling the plug won't help. Sorry 'bout that.

Let's say the pump is bad. If that was true, then you could spray starter fluid into the airbox for say two to three seconds and try to start the engine. IF you have spark, you should get the engine to cough or start for a few moments. Works for me.

Even pull the plug off the fuel pump when you do the above for superstition.

You have sparK???????????? any spark?

If you pull the two bottom sparkplugs and hold a finger over one plug hole at a time, do the front and rear rotor pulses feel similar when the engine is turned over?. Have someone crank the engine over when you try that.

 

i haven't put fingers over the holes but i've listened while cranking and all pulses on each rotor sounded strong and even. I've checked for spark and it seemed that with my original ignition coils that i was getting erratic sparking and not sparking. I changed them out with some s4 n/a coils and i got spark an all 4 plugs all the time. so i stuck em in and still not running. I'll try the feeling over plug holes, checking for spark again, and starter fluid tomorrow. it WILL be safe to spray starter fluid in my tid since i got a turbo right?

 

I have had no problem spraying in the airfilter on a turbo or non turbo. I only do it for a count of two and maybe three seconds max.

You know something. If the fuel pump is working, you should be able to hear the fuel flowing back into the tank and thru the fuel rails. Once the pressure gets higher than the fuel pressure regulator setting of approx 37psi, the rest of the fuel/fuel pressure should go back into the tank. In other words a flowing condition all the time if the pump is running.

Got your fuel lines on right??? ON a USA engine the filter feeds the front fuel line on the engine. IF you have a JSPEC engine it would go to the rear feed line on the engine.

Maybe you could remove the return fuel line on the engine and connect a long piece of hose to it (the metal line coming off the engine) and put the other end in a gas can/bucket, and then turn the key to ON with the jumper in the connector and see if your getting a solid flow of gas???? I never thought about it before, but if you get a steady flow of gas, that means your pump is at least putting out 37-39psi which is good enough to start and run a engine. sorry, I don't do pm's. don't take it personal, please.

P.S. The line I suggested for the gas can/bucket would not have to be the expensive injection fuel line. Just some cheap rubber hose that fits will do as long as you never use it as fuel line on the engine in the future.

 

well, i checked each plug wire for spark with a plug on it and all of them have it. i didn't have anyone to help me with the compression feeler test so i couldn't do that. i sprayed starter fluid onto the air filter, walked over and put my foot on the gas pedal all the way down and tried to start it. it did nothing but crank. so i have no clue what's going on. i called MAZ-MAX over in downtown houston and they said that it costs $180 just to walk in the door. that includes fuel pressure check, compression check, and something else that i can't remember what he said. that's ridiculous. that's $60 for each test. i can do that myself. i'm just going to wait for my fuel pump today, replace it and see what that does. i don't know what else to do.

 

could this have anything to do with why it's not starting?

http://www.flickr.com/photo_zoom.gne?id=91454135&size=o

 

can anyone help?