sup org,
so i just read a thread by aackshun and it made me remember to post this.

mods:
2000 VERIABLE INTAKE
00 upper and lower manifold, 00 injectors and rail, shorty headers, ypipe, megan test pipe, cat back, short ram intake. UNTUNED

so after the VI iv been chasing vacuum leaks.
after new lower intake and upper intake gaskets, pcv grommit, evap solenoid and connector, and a new throttle body connector bank one is still lean.

the only other thing i can think of is an o2 but i have no code and with the scantool it switches voltage pretty regular.

anyone else have this issue after a VI? any common issues that would only cause bank one to be lean?

i appreciate all the help. thanks in advance

 

bumpskis
anyone? i may just throw some O2s in it

 

nobody has had this issue?

 

I have this code pop up. It goes away so I'm like what ev

 

bump

 

How can it be lean ?!? u got 5gen injectors? And a bad o2 would give a richer limp mode condition... Maybe ur o2's are fouled from the bigger injectors and no tuning? I dunno :S

 

thats exactly my dilemma. not only is it lean but its only lean on one bank.

 

I just had this problem on my car, accept bank 2 was the bank that was too lean. I heard a dirty MAF sensor can be the culprit behind this so cleaned mine off with some spray cleaner and put everything back together. I've put 100 miles on my car since then and no check engine light so far. If not that, I would put my money on you still having a vacumm leak somewhere. Check and recheck everything, chances are theres an old rubber hose or gasket somewhere that is cracked and has a leak.

 

Sure you got good injectors? Is your coolant temp sensor still factory? If you are actually running lean then it is either too much air, possibly a bad MAF, or too little fuel meaning something with your injectors or fuel system

 

Yeah the ECT sensor is OEM. There's no external vacuum leak I solved those issues. Wouldn't the maf cause the whole engine to be lean?The injectors are used but they flow well.


So what's a good way to check the ECT sensor?
I think I'll clean the maf again too.
I want to rule out the injectors because I tested them before the VI swap.


I will report the results of the maf cleaning.


Thanks everybody

 

Likely the MAF will respond to a cleaning but you said you have already cleaned it? Thats bad news and likely you will need a new one. To test the ECTS just follow the FSM guidelines on page EC-125. It gives you what the resistance should be at a given temperature. Really though, a new one is $30 from Nissan(dont get an auto parts store sensor) and it will likely improve your engine performance. Do you ever have to give your car gas at morning start-up to keep it going? This is a sure fire way to tell if it is bad. The ECTS is a pretty important sensor though especially at operating temperatures and if it is factory I would replace it anyways. After replacing the MAF and the ECTS I think you will solve your issues as both are hugely important. Hope this helps

 

Could still be injector related just not the injector itself what happens on occasion is the o-ring will not seal properly and create a minor vacuum leak... to much unmetered air equals lean condition

 

Pull the plugs and see if it is the entire bank or just one cylinder that's uber lean.

 

as a matter of fact, when i start the car i wait until the fuel pumps initial prime is done and the relay click or it will start and die. it still tries to die but theres enough fuel in the manifold to keep it running. so im going to replace the ECT.
i did clean the maf about 2 months ago. i hope its not bad those are expensive.
thanks you for the info
i would totally agree with this but i replaced them all when i swapped the VI
will do.
its -2 here in the chi so i think im going to wait until it warms up a little



thank you everybody for contributing this is driving me bonkers. but i feel now i may be getting closer to the resolution.