Jump to content
SAU Community

Recommended Posts

Hi guys.

Well my car has had issues as per this post.

http://www.skylinesaustralia.com/forums/in...howtopic=169954

So basically last night i put on a whole new ECU and issue was still there no change. so i guess it's not mapping or anything.

The cold start as you can see sux, and i noticed a spike on the AFM, no idea what that means.

In the Surging log, you will see that the O2 sensor drops to zero half way though the boost building ie: airflow. and then comes back, fairly apparent in the first 10 runs. I have no idea what couses this, but on another ecu it did exactly thesame.

WHat could be causing this.

Can somone with some knolage have a look for me. PLEASE.

Wogs_Log_Files.zip

  • Replies 44
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Posted Images

i dont have any software to read through all those logs, but ill recommend again to try yet another AFM just to tripple check thats not the problem. any chance you can also borrow someones AAC valve as those 2 would be the first things i'd be checking (even if you've already double checked them - once more wont hurt).

Hay mate, had to different AFm on it, and i have a NEAR new ACC valve, and it's not that.

Had a different computer sotck and mapped, and same issue.

Maybe i will try a new O2 sensor and remove the cat sensor.

just some of my observations...

1. you are maxing out your AFM :woot: and by the looks of it the wiring from the AMF has a bad ground as if it is earthing out somewhere. this is possible causing your surging.

2. you are running way to much timing at full boost possibly to much between 2000 and 2600 rpm.

cheers!

HAAAY MATE your my herrooo.

Ok so how do i check the wiring, i suppose just go through the whole loome?

How did you pick up the wiring earthign issue? so i can have some idea what to look for if i fix it?

I know the AFM is maxing out, but need to put up withit, will the maxing out couse a surge?

The timming has never been an issue before this started to happen. It worked fine for 6 months, and teh ecu is read only so i can't reprogram it.

Maybe beace the SAFC II i took out -10 on the fuel map, it is puting in too much timming. Humm will need to put that back.

OK so how do i actually fix the AFM thing, apart form an Z32 airflow meter.

Any reasdon why the O2 sensor drops out like it does?

check the AFM wiring.. it could be shorting like ceffie said.. look for exposed wire or anything out of the ordinary.. if your AFM is doing anything wrong, it will throw out everything.. idle, power etc.

Ok well last night i go tin late, but i did manage to pressurise the FMIC and piping, minus the plenum, and all good, pressure at 50psi stable and holding, managed to blow up the end caps i was using though. LOL.

Put in new o2 sensor, still thesame. I have started with the wiring, but dam there is a lot of it. Hoping to do a lot more tonight with the wiring issues.

Follow the wiring diagram and go from there.

If you have any more ideas keep em comming.

Thanks guys, i know i seam a pain in the ass askling all the time, but here in tas there are no people who have a clue, yeah a mechanic will look over it, but have no idea what to look for on an imported car.

Thanks

Ok well last night i go tin late, but i did manage to pressurise the FMIC and piping, minus the plenum, and all good, pressure at 50psi stable and holding, managed to blow up the end caps i was using though. LOL.

Put in new o2 sensor, still thesame. I have started with the wiring, but dam there is a lot of it. Hoping to do a lot more tonight with the wiring issues.

Follow the wiring diagram and go from there.

If you have any more ideas keep em comming.

Thanks guys, i know i seam a pain in the ass askling all the time, but here in tas there are no people who have a clue, yeah a mechanic will look over it, but have no idea what to look for on an imported car.

Thanks

Sounds like you've got a leak under vacuum if the 02 sensor goes to zero before it gets to boost. Please dont tell me you've vented the rocker covers and havn't bunged the PCV vavle. Also if there is too much base timing then you can sometimes get an idle surge. remember the only proper way of checking the base timing is to do it with a nissan consult - bar none!!!!

I have Consult, and yeah the base timing is at 12 due to runing lower octane fuel.

The 02 sensors goes to zero WHILE on boost, that is the strange thing. No i acctually took the tubo outlett off and then the intake off. Then ganged one up and put a cap with a pressure line tap in the other and pressurised up to 50 psi. So it bypassed any of the PCV stuff.

I Have pulled the PCV off and checked and it was warking correctly.

The sure is not at idle, it just that it doesn't start properly, the surge is coming onto boost at low rpm but high TP.

I have Consult, and yeah the base timing is at 12 due to runing lower octane fuel.

The 02 sensors goes to zero WHILE on boost, that is the strange thing. No i acctually took the tubo outlett off and then the intake off. Then ganged one up and put a cap with a pressure line tap in the other and pressurised up to 50 psi. So it bypassed any of the PCV stuff.

I Have pulled the PCV off and checked and it was warking correctly.

The sure is not at idle, it just that it doesn't start properly, the surge is coming onto boost at low rpm but high TP.

The timing will be 12 because you have too much bypass air around the IAC, screw it in until the base timing comes back to 15 deg.

no i have set the CAS to 12 deg base idle, the car was tuned on 98 plus, and i am running premium at the moment. I have gone back to 98 plus and it made no differance after i reset the timming.

Ok i will post a new log modified to show the things i am talking about.

Ok modified surging log, about 1/3 of the way in very obvious, when viewing load RPM, AFM, O2 and TP, and have a look you will see that the air is ramping up but the 02 drops out.

surgingcold.zip

(im just using excel...i found the points, i edited post above)

after looking at that, the times it happens you either arent putting your foot all the way down, or ur TPS is very slow to react. maybe TPS needs adjusting/replacing

look at the blue line:

post-4553-1180587601_thumb.jpg

and notice the dutycycle drops off, ie the ecu is purposely putting less fuel in. my guess is that the drop seems consistent from switching from open loop to closed loop. TPS then only hits the full 4V after the ecu has decided to enter closed loop mode (ie cruising/14.7:1 AFR).

what happens if u run with TPS disconnected? (im not sure if thats a limp mode condition or not)

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • If it dies, then bypass. The task isn't difficult. I have one running on a standard R32 FPCM. That's after nearly 20 years of it running an 040, which pull substantially more current than the Walbro. They're not the same module, but I'd hope it indicates that the R33 one should be man enough for the job. I think people kill them when putting proper sized pumps on them, not these little toy pumps we're talking about here.
    • Silicone spray won't hurt anything. And if it does, that's an opportunity to put some solid steel spherical bushings in, so you can really learn what suspension noise sounds like, If you're going to try it, just spray one bush at a time, so you can work out which one is actually noisy. My best guess is that if the noise started only since putting the coilovers in, then it is just noise being transmitted up through the top mounts of the struts, and not necessarily "new" noise from bushes. But it's almost impossible to know.
    • Are you saying the 34 is SUV height, and not that we're talking about an SUV here? (because if we're talking about an SUV, you don't fix them. You just replace them when something breaks. Not worth establishing sufficient emotional connection with an SUV to warrant doing any work on one). I wouldn't jack my car up on a short little loop of 10mm steel rod poking out through a hole in the bumper bar, front or rear end. I realise that we're probably not talking about that type of loop at the front, being the one under/behind the bar on a Skyline.... but even for that one, trying to jack up on what amounts to a thin piece of steel, designed purely for withstanding a horizontal tension force, not a vertical compressive force (and so would be prone to buckling/crushing) and, my most particular bitch about it - located RIGHT AT THE EXTREME FRONT OF THE CAR, applying a load up through the radiator support panel, etc, with almost the entire mass of the car cantilevered between there and the rear wheels? Nope. Not doing that. Not on the regular. That structure out there in front of the front crossmember is not designed to carry load in the vertical direction. Not really designed to carry any load at all, really. The chassis rail that the tow point is connected to would be fine loaded in tension, as per towing. Not intended to carry the mass of the whole car, especially loaded all on one rail, with twisting and all sorts of shitty load distribution going on. No, I will happily drive up on some pieces of wood, thanks. That can only happen on driven wheels, and they are at the other end of the car, and this problem does not exist at that end of the car. And even then, I have been known to drive up on at least 1x piece of 2x8 each side at the rear, simply to reduce the amount of jack pumping necessary to get the car up high enough for the jack stands. What really really shits me about Skylines is the lack of decent places for chassis stands at either end of the car. You'd think they'd be designed into the crossmembers.
    • I've got MCA Blues on my V36 Skyline, and while I've managed to sort out issues with scrubbing/bottoming out by raising it a smidge and increasing the damping hardness, the rear end still sounds *super* noisy when driving on anything other than the flattest surface imaginable. It sounds like a small party of flamingos are just chatting away in the back, which makes me think there are several link points in the suspension contributing to the noise. Am I hearing dried out/worn bushings? None of it sounds like metal-on-metal, it sounds more like hard rubber squeaking on metal. It's been suggested that a bit of silicon spray on each bushing might quiet them down, but I'm not sure what material the current bushings are made of (probably factory, I imagine) and whether silicon spray will degrade that material.
    • The obvious answer here is get a ND2/3 RF with the Targa top. The red is nicer, too!
×
×
  • Create New...