Fuel System Issues?

[vxcp]

I'd replace it again

Roger that.

With the bucking stopping when your tank is full, I have to defer to the more experienced gang here.

Yes, thats the part I can't quite figure out, thinking that maybe filling up is breaking a vacuum on the tank. What sorts of emissions hardware is there on the VX? Perhaps something is plugged?

Hope it works out for you, I know this takes away from that new car giddy feeling...but it should be resolved pretty soon I'd think.

Yes, its been a long few days. Looking forward to getting the vx up and running like a champ.

[Y33TREKker]

Low pressure on the fuel line could have also been caused by the Fuel Pressure Regulator being faulty, which is a common problem on VX's. A relatively easy replacement cost/procedure too. Irregular fuel pressures from a faulty FPR could have also caused the low voltage readings responsible for the codes you were getting from the O2 sensors.

I don't know exactly what goes wrong with the stock FPR's on VX's, but given the mileage on the one you purchased, it's likely that the original is still in place, so it would be a likely place to start.

Congrats on the purchase, and welcome to the site.

[tom4bren]

Have them clean the MAF as well. Those symptoms were very similar to some problems I had when I first got mine (including running better with a full tank).

[MSHardeman]

FPR replacement how-to:
http://www.vehicross.info/forums/sho...or+replacement
I used Dino's instructions and got the fuel pressure regulator replaced in not time with minimal knuckle damage.

[Dmitrikr]

Have them clean the MAF as well. Those symptoms were very similar to some problems I had when I first got mine (including running better with a full tank).

got four Isuzus last year in the shop with codes for both O2 sensors. But the problems were - MAF sensors on two; on other two-someone forgot to tight the clamp at air intake hose to plenum - created air leak not counted by MAF sensor