Jump to content
SAU Community

Recommended Posts

Hey guys - got a problem to report - wondering if anyone can help out.

Last night me thinks - it's cold, 0.9 bar is going to be waaay safe so I dial it in and plant it in fourth. At this point a few things happened - which have happened before:

first boost comes up - ok, all good

then suddenly everything cuts completely for about half a sec - felt like I'd turned the key off!

then it cuts back in...

then it misfires around 5000rpm - which I'm guessing is the plugs and I'm hopefully going to fix that problem today...

the first problem of the engine/revs cut I'm thinking is the AFM going past it's voltage limit and shutting down.. does this sound right? what can I do to fix it? I've sprayed/cleaned it with heaps and heaps of electrical cleaner which didn't seem to make much difference..

Any ideas?

Link to comment
https://www.sau.com.au/forums/topic/17194-afm-problems-i-think/
Share on other sites

Caminperth,

I had the same thing happen to me when I had my car at about 13psi while mucking around. It was fine on the dyno but as soon as it was on the road it would start to have the problem you described.

The guy told me that it would be even worse on a colder day due to the fact that there was too much air getting into the engine and the air/fuel ratios where not adjusting correctly on my stock ecu.

A SAFC would probably fix your problem, I have a simple Pivot air/fuel meter (1 universal setting) and adjusted it to make it a little bit leaner and it has fixed the problem for me.

I am no mechanic/tuner so it is just a suggestion ;)

Daniel

aidwin - as you said man - it's not the speed cut..

b005t - yea - i know what the speed cut is like and this ain't it. :rolleyes: and yea - am still running stock cooler...

adrian - could be - but it's fully intermitent..

bam - i wish i could afford the gtr!

daniel - i've got an afc and itc (old skool apexi fuel and ignition controllers) and that should sort out the fuel issuses at higher boost...

i fixed up the plug issue today - tho can't really try it out in this weather.. :)

still at a loss as to what it could be.. still got an inkling it's the airflow meter maxing out... will do it more when there's cold weather due to more air due to the density change... sound right?

Cam,

It's the boost cut/fuel cut. The boost controller has nothing to do with it, it's the AFM that tells the computer when it senses too much air flowing, which means too much boost, and it will hit boost cut, resulting in a nasty sudden halt to the car:D

You'll need to replace your ECU or get a fuel cut defender to stop this happening. It is worsened by the fact you have a stock cooler, and cold air is denser, thereby the AFM senses more air flowing:D

Hope that made sense (and is true)

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

    • LOL.... a good amount of people (not all) on that continent seem to know everything and like to measure things in bananas, football fields, statue of liberties instead of the metric system lol.
    • I assume the modules are similar enough, so if you've had no issues I don't see why I would. I have tried to find a wiring diagram for the FPCM / fuel pump circuit, but I can't find it anywhere. Otherwise, I would just do some wire cutting and joining at the FPCM and give the 12 V supplied to the FPCM directly to the pump instead. If you know anyone that could help with wiring diagrams, I'd be very happy  
    • 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.
×
×
  • Create New...