Misfiring and i don't know why, NEED HELP ASAP!!!!!!

[UZZ30-Québec]

damn, i'm going for a trip saturday and the car decided to misfire today.

I explain.

last week, car was working perfectly (except the post i made that sometime it wants to stall with A/C on on a red light)

I decided to "dynamat" the car, put insonorisating stuff everywhere.

- I removed all trims, console etc... then, need to remove the fuel tank in the trunk.

1- I disassembled the pressure line under the hood and use the fuel pump to drain the fuel tank (while jumping FP with B+) it worked perfectly.

unbolt fuel lines, remove the tank everything's ok.

finished my work today, reinstalled the fuel tank, put 6 gallons of fuel in the tank, primed the lines with (on/off on/off) started the car. took a few seconds but it started. then, the engine revs very wrong, like a missfire or more like a air/fuel mixture not OK or i don,t know...

when i "pump" the throttle, i can rev it to 6000RPM, when i give gas directly, miss fire, back fire, stalls, everything.

I made a small video of what the engine does so you can have precise situation.

The battery drained during the job, i jumpstarted the car to start it.

Also, there's fuel pressure, I do hear the pump working always on, and i also hear fuel returning to the tank so i think fuel pressure is OK (or maybe the pressure regulator is stick??? dunno?)

anyway, here's the video, thanx a lot for your support guys, i really need to get this thing working quickly.

http://media.putfile.com/SC400trouble

 

[Peewee]

Recheck everything you've undone/redone and make sure all connections are perfect, and back in the correct order.

It sounds like fuel is not reaching the motor correctly.

Are you sure you put the fuel lines back on the tank end correctly?
Its probably easy to get the backwards?

 

[Zuffen]

If you pumped all the gas out with the fuel pump you may find the screen on the pump pickup is blocked or the fuel filter itself is now blocked.

You would be surprised at the amount of gunk in a fuel tank.

 

[UZZ30-Québec]

Recheck everything you've undone/redone and make sure all connections are perfect, and back in the correct order.

It sounds like fuel is not reaching the motor correctly.

Are you sure you put the fuel lines back on the tank end correctly?
Its probably easy to get the backwards?

There's a Pin on the pressure line and no pin on the return line, you can't install them on the wrong side.

I changed the fuel filter today, it still do the same thing. Think i'll have to remove some of my insulating stuff and check the fuel pump screen...

 

[UZZ30-Québec]

UPDATE :

lines are OK, fuel pump filter is ok i can see fuel returning in the tank.

When I jump FP with B+ while the engine is ON, everything's great, engine is running great, looks like the pump gives more pressure. I'll try to check what's going on with the wiring...

 

[UZZ30-Québec]

finally, i think that "fuel returning in the tank" sound is the problem, when i activate the pump a **** load of fuel just do like a "geyser" in the thank.

and with a flashlight i noticed that there is a "pin" for BOTH lines... (dumb me i know...)

flushing the tank again, i'll switch the lines and i think everything will be OK. But i still can drain the tank via the pressure line (but there's not a lot of flow.) So this had made me think that lines were OK.

i'll be back in an hour to post the restults.

BTW, if you notice how the fuel pump system is made in the SC tank, you can't clog the filter by draining the tank. there's a "separator" system with make the fuel pump always only have fresh fuel in it's pan. pretty cool system!

 

[UZZ30-Québec]

Fixed, finally, the top copper washer wasn't on the pressure fuel line, so all the pressure was returning to the tank, my famous "geyser"

shame on me, shame on me....

 

[Peewee]

Which bit?

 

[UZZ30-Québec]

???

sorry, i'm not very good with english expressions, specially australians ones (but i'm trying to learn with Paul Hogan movies lol) j/k

 

[Peewee]

Where abouts was this copper washer you spoke of?

 

[UZZ30-Québec]

there's one over the fuel line connection, and one under the fuel line connection. (there's always 2 on a bolted fuel line connection anyway)

the top one (facing the fuel tank) was missing.

on the 2 other fuel lines, the washer was stuck on the tank, so i didn't double check when i reassembled everything.

 

[Peewee]

Ahh k. Never had a car with 'bolt on' fittings at the tank end.