Hey guys just installed a new walbro 255 lhp pump from my oem. At first the car shut off after 5 minutes of driving. Then turned on fine. Now when I'm at a stop sometimes it drops relatively low below 1000rpm and jumps back up and fluctuates again... Is it a bad pump? Or does it need sometime to adjust.. Thanks

 

Did you install injectors at the same time? If yes, you need a tune. If you just installed the fuel pump, it sounds like you have low fuel pressure or something. Did you check the vacuum lines on the FPR and re-check all your connections?

Also do you have a wideband AFR gauge?

 

Nope only the fuel pump... Plan to do injectors though before I go e85 though. And no I don't have a wideband gauge.. How can I check manually..