I got a 92 EG with a stock b18b (I/H/E) with no cats. Last weekend we Put it in the dyno and is running really lean, I have an Air Fuel gauge and it says is lean too. The check engine light doesn't come on for a few minutes, but after driving it if I stay on the gas for more than 1 minute or so it comes on, but when turn off my car and turn it on again it doesn't come on until I drive it again. I still have the stock 1.5 fuel pump in it, and I just changed the fuel filter too.

Does anybody knows what might it be?... I think is either the fuel pump or the O2 sensor, but I dont want to spend all that money for no reason so, If you guys know what it might be, please let me know... thanks in advance!!

 

probably the 02 sensor, have you checked the cel?

 

No I havent checked it yet... do you think the stock 1.5 pump is ok..??

 

your fuel pump should be fine, it could be that your injectors are spraying irregular
(if there are alot of carbon deposite buildups, it could cause this)

try a fuel induction cleaner, it sprays right into the throttlebody while running

it is also likely to be your o2 sensor like he said check the cell

 

o2 sensor, or fuel filter is clogged, or if you have a adjustable fuel pressure regulator, turn that bitch up.

One of my boy's had that same problem, he just got a BOSCH o2 , sensor, your stock fuel pump, should be fine, unless your runnin' some hardcore ****.