bad fuel filter/pump

[dkauffman05]

Well i got my 5.3 swap running this weekend and having a what i think is a fuel issue. It fired up ran ok but a little rough long story short i found a bad o2 sensor. I un plugged both of them put it in closed loop now it idles nice and smooth but when i try to drive it it will barley go acts like its starving for fuel. I don't have any way of checking pressure. J am using a e2000 pump and c5 vette filter/ regulator from the stock 68 tank and while running i can open the fuel cap and hear what sounds like a waterfall of fuel returning back to the tank. Anyone ever heard of a vette filter bypassing too much fuel? When i first tried to start it i had the fuel inlet and bypass lines reversed pushing pressure into the return side. Do you think i could have messed up the regulator or mabee i have a bad pump? Only codes are for having the o2's unplugged.

[clinebarger]

The 'Vette filters work great, Never had a problem with them. I use Delco filters though....Where did you get your filter? Check fuel pressure BEFORE replacing parts, 58 psi at all times.

[dkauffman05]

Its a wix from sumitt

[clinebarger]

Originally Posted by dkauffman05

Its a wix from sumitt

Wix is a good brand....I doubt its bad. With ANY swap.....Injectors are bad about getting clogged with varnish from the fuel sitting in the rails, Ethanol in the fuel has made this problem worse.

[dkauffman05]

I have a fuel injection shop near me i need to call and see about getting them cleaned. I did pick up a new fuel pump and made no difference. I can go down the road reach back and pinch the return line and it picks up a little but not great.

[dkauffman05]

I got my injectors out and going to drop them off tuesday to get cleaned. I am still worried about the regulator since i hooked the fuel pump feed into the return outlet and worried i messed up something inside it.I used a friends matco fuel pressure kit this weekend but since i have an fittings snd billet fuel rails we couldn't figure out a way to use it. I was thinking about putting the injectors back in and grabbing a new regulator.

[dkauffman05]

Ok well i just found a picture of the inside of a vette filter and dosen't look like i could hurt it so i guess off to get injectors cleaned.

[dkauffman05]

Well got the injectors cleaned,new airtex e2000 fuel pump, new regulator. Still have the o2's unplugged to eliminate them for now and still it stumbles horribly through most of the rpm range past mabee 2500 just like its running out of fuel. No codes other than o2's being unplugged.

[clinebarger]

The O2 sensors are used for SEVERAL "self/functional test" in the ECM, With out them the ECM doesnt know its running lean or rich, If the O2s were operating the ECM would set lean code IF the engine is running lean.

I DO NOT like external fuel pumps.....You could be sucking air or have a bad cavitation problem. The frame mounted pump is drawing fuel through the sender...Correct? If so.....You need to draw fuel from the bottem of the tank, Its easy to do on 67-72 trucks....Bulk head fitting & a hole in the floor.

[dkauffman05]

I plugged the o2 sensors back in lastnight let it warm up and went for s drive. Its ok it your at 1/4 throttle and if you give it full throttle it slmost feels like something is being bypassed and it pulls hard, but anywhere else in the throttle range it just wouldn't go.

[dkauffman05]

During that ride i did get po300 random misfire code and po151 bank 2 sensor 1 low voltage.