bank 1 sensor 1 o2 sensor and a knock sensor...

FWIW the fuel pump Derek@EDO is running and the one in White1's truck is listed at Summit as a store brand pump for a Mustang, but is actually a Walbro unit that works just like stock (Walbro stamped on it and all)

 

just put a new o2 sensor in and the lights still on...

 

I have a Walbro 255 and the check valve doesn't work on it either. Granted my system is TBI and was never intended to hold pressure but I've plugged the bleed off hole so that it should hold pressure if the pump check valve was any good. On top of that my pump is just over a year old and screams like a banshee. My roomate was about 60 yards across the parking lot getting out of his truck as I was starting mine today and he heard my fuel pump screaming loud and clear. Its been that way for a few months but it doesn't seem to be effecting it any.

 

mine does the same, I just have to put the key to the front for 2-3seconds then it fires right up, no problems though so I just let it be...

 

Same here.

 

someone told me i could put a check valve on the line right in front of the fuel filter so the fuel wont leak back down into the tank when i turn it off.

 

theyre right .i went through 3 warlboros before i did a aeromotive exernal setup.warls did the same thing to me.plus 2 of them only lasted a short time.i installed check valave to hold the pressure and it did work out 4 me.then i had the same issue with the external setup and installed a inline check valve and it cured it .starts right up like new again.

 

my 89 5.0 has the GSS340 pump with the same symptoms, but I always thought it was normal since it acted like the factory mustang pump

 

on the new pump . . . did you swap over the brass fitting on the old over to the new pump ?

 

i dont think so, i dont rem a brass fitting?