Thread: Even more build woes...

Disconnected the primary o2 sensor today for a few minutes just to see what would happen, and I had absolutely no change whatsoever. Would this mean that the o2 sensor I have is defective, or that the problem is somewhere else? Now it's not bogging on cold start up, but shortly after the temps rise it gets worse and backfires a lot, with the o2 sensor disconnected.

the CTS is soooooo touchy, if it goes bad it can cause you all kinds of problems, personally my cts was getting my ems to think the temps were real hot, so on start ups, my car was running really rich becuase the computer adjusted the fuel off the bat for hot temps and it also retarded my timing, while all along the car was on cold start up.

if you are seeing normal readings i wouldnt suspect that the cts as being bad, also with my cts for some odd reason my temp gauge wasnt reading abnormal when the cts went bad so it really threw me off, i eventually tracked the cts down as being the problem after going nuts.

did you check the fuel pressure regulator?
are you getting consistant fuel pressure reading with acc on and engine off?
are you getting consistant fuel pressure readings with engine on?
are you getting consistant steady fuel pressure readings with engine on vac line for fpr off?

fuel system is very small and easy to work with to eliminate it as being a culpreate

check the ohms at cold start, then check them when the car warms up

Haven't checked FPR just yet.
I do get good fuel pressure when primed.
I don't really get consistent fuel pressures when the engine is running. It's really bouncy, but in the correct range. I haven't checked the fuel pressure while racing the engine. I haven't tried with the engine on and the vac line disconnected from the FPR. Good advice!

I'll try this after dinner and see what happens. I'll be really pissed if it is in fact the AFPR. GREG! Hope this bad boy has some sort of warranty

i had my nismo afpr a total of 1300 miles before it went bad, i mentioned it to my local shop here i get all my problems/tuning fixed/done and they said nismo FPR are really less than par up against the aeromotive fpr's they just arent up to the same quality as on the high end fuel counterparts.

with the fuel pressure not being steady would throw a flag for me, the fuel pressure should be pretty stable, i know before mine went bad it was uber steady along. even with my stock fpr on now, my fuel pressure is stable..t could just be nothing, but i would definitly check the FPR...as with the fpr going bad its a mechanical problem and you cant just go in and look and see if the volts or ohms are off, mechanical problems suck hard becuase they have to be chased down.

it could also be that you arent useing a liquid filled fpr gauge, altho even then i get steady readings with a non liquid filled gauge so i donno

I'm thinking mine might be bad also, the gauge bounces like a mad man at idle. I'm gonna try my stock one this weekend to see what happens since I'm still at 3 bar lol

Turns out it wasn't the AFPR. Car was just running really lean. Pulled the plugs again and the ground was white, while the electrode base ceramic was BLACK on half, and super clean white on the other. The base of the threads were also black with carbon.

Was on the phone with Calum and he had me raise the injector latency way up to like 1.1ms, which I thought would be too high, but he re-assured me it's okay. Then we walked the K value up to around 230 from 218, and then back down to around 200.

She's idling much better, back fires on DECEL while in neutral, which freaked me out at first. I've never had the car backfire so loud before, but it doesn't really bother me I guess. 3" exhaust, anyone?

Tomorrow (it's raining right now) I'm going to take it around the block and do some datalogging from 2K~4K at steady speeds, and send them off for analysis. If the car seems to run fine N/A around the block a few times, I plan on hooking the intercooler piping back up, and taking it around the block few times to see how she reacts. Got my fingers crossed that I may have finally nipped this in the butt.

Can you e-mail me your bin?

Is it all the time?(Not really a good thing) or right after you really get on it and let go of the gas quickly, or with a cold motor (normal)

Backfiring (unless you are letting go of the gas quick after a jolt with the boost) means the car is running too rich(normally too rich is the case) or too lean, and something isn't right either way.

The O2 might be something you want to look further into. According to the Nissan FSM you would have an issue with your O2. (A bad O2 tends to make cars run rich from my experiences.) It takes a while for some sensors to really start doing theirs jobs (they have to warm up first)

Just e-mailed you the bin we were working with last night.

Not really ALL the time, but then again I don't really remember now (I've slept since then )

It's backfiring N/A right now. The turbo isn't in play. Of course it's only on decel, and it's usually small pops.