Jump to content
SAU Community

Recommended Posts

Hi all,

I've spent a lot of time searching through the forums to find a solution to a problem i have with my R32 GTR. I have a few questions i'm hoping you could answer, which i couldn't easily find whilst searching.

Basically _i think_ my car is suffering from faulty AFM's. I have read that its quite common that the AFM's have dry solder cracks occuring from the old age. I disconnected them this morning and rev'd the car and it went in to the safe mode, which sounds/feels very similar to what happens quite often when i'm driving.

I want to try and fix the issue by following this tutorial: Fixing your RB26 Afm's

If this doesn't work, i was looking in to buying Nismo air flow meters (http://www.nengun.com/nismo/air-flow-meter). I want these purely because they appear to be a straight plug n play. My car has been in the work shop numerous times in the last year and its a real hassle getting it out there.

If i were to buy the nismo air flow meter and plug them in, would i require a re-tune? If the answer is yes then i would most likely get some Z32's as they are cheaper, and it would end up in the work shop anyway :ermm:If it does require a re-tune, could someone tell me the reason why, and also what would happen if i didn't have a re-tune. I have a Mines ECU in case you need to know.

Thanks in advance for any help you can offer!

Mike

Link to comment
https://www.sau.com.au/forums/topic/332093-possible-faulty-afm-nismo-afm/
Share on other sites

Short answer yes, retune needed.. but if you have Nistune you could just change the AFM in the Nistune software and it will do all the voltage corrections.

AFM lesson, volt range 0v = no airflow, 1v = approx idling, 5v = maximum airflow the MAF can handle. The stock RB26 AFMs handle 440hp (absolute max) as a pair. While the Nismo AFMs handle 775 hp (again absolute max) as a pair.

For the sake of argument, your stock AFMs are maxed out at 5v, which means your making up to 440hp, the ECU/current tune is mixing in the required fuel to make that power. If you put the Nismo AFMs in, and don't touch the tune, the engine will try to make that same power (440hp), but will only be reporting about 3-4v to the ECU, which the ECU is then mixing in the fuel to make about 200-300hp.. which means the engine will run super lean and destroy itself.

My advice, get rid of that Mine's chip, Nistune it, and get a full proper tune.

Z32's are cheaper, but they are a 80mm shell vs the stock/Nismo afm which is a 65mm shell. If you have pods, you will have to sell your current pods+elbows and buy 80mm compatible pods+elbows.. if you have the stock airbox, you'll have to get rid of it and go 80mm compatible pods+elbows.

My advice, get rid of that Mine's chip, Nistune it, and get a full proper tune.

Z32's are cheaper, but they are a 80mm shell vs the stock/Nismo afm which is a 65mm shell. If you have pods, you will have to sell your current pods+elbows and buy 80mm compatible pods+elbows.. if you have the stock airbox, you'll have to get rid of it and go 80mm compatible pods+elbows.

Hey there,

Thanks for the info, appreciate it :ermm:

Is it possible to pick up new genuine oem air flow meters? I want to avoid going to the workshop again because it will mean new piping + Nistune chip + retune. If it comes to that, then obviously i will. I was having a quick look for genuine oem afm's and i couldn't find much that wasn't referring to the Z32 or the Nismo afm's. I found this: http://www.rhdjapan.com/nissan-oem-maf-mas...r-58012?nflag=1 which seems to be genuine oem. Do you forsee anything wrong with these parts? It is quite a bit more expensive than the Z32's, but in the end it will even out if i can just install the oem ones myself at home.

Cheers :P

Just remember that the stock RB26 AFMs only have resolution up to 328kw (and then again, in the real world about 290-310kw max), those genuine OEM ones will do as you want (at a expensive price), plug straight in and nothing will need to be done tune-wise, except for maybe a ECU reset.

If you ever want to go above that power level you will need Nismo AFMs or 80mm AFMs (Z32, RB25 etc) anyway. If you are willing to upgrade to 80mm piping, try a pair of 2nd hand RB25 AFMs, as a pair they support 400kw.

Just remember that the stock RB26 AFMs only have resolution up to 328kw (and then again, in the real world about 290-310kw max), those genuine OEM ones will do as you want (at a expensive price), plug straight in and nothing will need to be done tune-wise, except for maybe a ECU reset.

If you ever want to go above that power level you will need Nismo AFMs or 80mm AFMs (Z32, RB25 etc) anyway. If you are willing to upgrade to 80mm piping, try a pair of 2nd hand RB25 AFMs, as a pair they support 400kw.

Alrighty then, well i have a bit to think about then i guess. I've bought some CRC cleaner and will see if that clears up my problems. If not, i'll be going down the path of a new afm i guess. Thanks for the info! You've been a lot of help

Hi again, i've resoldered the joints in the AFM's and also given the sensors a good clean with a can of CRC contact cleaner. I've put the AFM's back in the car, however it seems to be running really rich. The engine gauge shows its warm (after about 15 mins idle), but when giving just a few revs to it, its spitting out a fair few dropplets of unburnt fuel.

I haven't really given this kind of thing much notice before, so i'm not sure if this is quite normal? Should i be worried? I haven't taken it out for a test drive yet, as i need to put the air filters back on. I also let it idle for 15 mins because the battery was flat and i had to jump start it. Any advice is welcome, thanks in advance :)

Did you reset the ECU? You need to disconnect the battery, and keep pumping the brake pedal to discharge what power is left in the system.

Hey there, no i haven't reset the ECU. I have a Mines ECU in there, will resetting it give the same results as a stock ECU? Btw, i checked my car yesterday and the battery is totally flat, had to unlock it with my key and everything. Not even the alarm went off when i did that. Would it be safe to say the there's no power in the system? I'll jump start it later today hopefully. Thanks

Mine's ECU is just a standard ECU with a piggyback inside. Functions just like a stock ECU, will self learn all the idle and timing settings again.

Hey again, so after another week of letting it sit in the garage, i put the air flow meters back in the car today, and jumped started the battery. Took it out for a spin, and i immediately noticed that it sounded different - it sounds like a wrx now. What could cause this to happen all of a sudden? It was fine 2 weeks ago (last time i started it), and now after starting it back up, it has the different sound. After letting it warm up a bit, there is very little power when i hit boost.

So far i have: cleaned the AFM's with a CRC contact cleaner, tried to resolder the joints within the AFM's. The battery was absolutely dead flat, so im assuming that the ECU would of reset. I also noticed its spitting out less unburnt fuel since last time.

Futher more, will driving the car in its current state cause damage to the engine? I'm planing to drop it in to unigroup at some point soon, but its quite a decent drive there, so i don't want to drive it there if its going to cause damage. What do you think? Thanks :ermm:

Edit: Just had a look at the ECU diagnostic and it gave me a code 55 - no malfunction

Edited by mick86

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

    • Update 3: Hi all It's been a while. Quite a lot of things happened in the meantime, among other things the car is (almost) back together and ready to be started again. Things that I fixed or changed: Full turbo removal, fitting back the OEM turbo oil hardlines. Had to do quite a bit of research and parts shopping to get every last piece that I need and make it work with the GT2860 turbos, but it does work and is not hard to do. Proves that the previous owner(s) just did not want to. While I was there I set the preload for the wastegates to 0,9bar to hopefully make it easier for the tuner to hit the 370hp I need for the legal inspections that will follow later on. Boost can always go up if necessary. Fitted a AN10 line from the catch can to the intake hose to make the catchcan and hopefully the cam covers a slight vacuum to have less restrictive oil returns from the head and not have mud build up as harshly in the lines and catch can. Removed the entire front interior just shy of the dashboard itself to clean up some of the absolutely horrendous wiring, (hopefully) fix the bumpy tacho and put in LED bulbs while I was there. Also put in bulbs where there was none before, like the airbag one. I also used that chance to remove the LED rpm gauge on the steering column, which was also wired in absolute horror show fashion. Moved the 4in1 Prosport gauge from sitting in front of the OEM oil pressure gauge to the center console vents, I used a 3D printed vent piece to hold that gauge there. The HKB steering wheel boss was likely on incorrectly as I sometimes noticed the indicator reset being uneven for left vs. right. In the meantime also installed an airbag delete resistor, as one should. Installed Cube Speed premium short shifter. Feels pretty nice, hope it'll work great too when I actually get to drive. Also put on a fancy Dragon Ball shift knob, cause why not. My buddy was kind enough to weld the rust hole in the back, it was basically rusted through in the lowermost corner of the passenger side trunk area where the wheel arch, trunk panel and rear quarter all meet. Obviously there is still a lot of crustiness in various areas but as long as it's not rusted out I'll just treat and isolate the corrosion and pretend it's not there. Also had to put down a new ground wire for the rear subframe as the original one was BARELY there. Probably a bit controversial depending on who you ask about this... but I ended up just covering the crack in the side of the engine block, the one above the oil feed, with JB Weld. I used a generous amount and roughed up the whole area with a Dremel before, so I hope this will hold the coolant where it should be for the foreseeable future. Did a cam cover gasket job as the half moons were a bit leaky, and there too one could see the people who worked on this car before me were absolute tools. The same half moons were probably used like 3 times without even cleaning the old RTV off. Dremeled out the inside of the flange where the turbine housing mates onto the exhaust manifolds so the diameter matches, as the OEM exhaust manifolds are even narrower than the turbine housings as we all know. Even if this doesn't do much, I had them out anyways, so can't harm. Ideally one would port-match both the turbo and the manifold to the gasket size but I really didn't feel up to disassembling the turbine housings. Wrapped turbo outlet dumps in heat wrap band. Will do the frontpipe again as well as now the oil leak which promted me to tear apart half the engine in the first place is hopefully fixed. Fitted an ATI super damper to get rid of the worn old harmonic balancer. Surely one of the easiest and most worth to do mods. But torquing that ARP bolt to spec was a bitch without being able to lock the flywheel. Did some minor adjustments in the ECU tables to change some things I didn't like, like the launch control that was ALWAYS active. Treated rusty spots and surface corrosion on places I could get to and on many spots under the car, not pretty or ideal but good enough for now. Removed the N1 rear spats and the carbon surrounding for the tailpipe to put them back on with new adhesive as the old one was lifting in many spots, not pretty. Took out the passenger rear lamp housing... what do you know. Amateur work screwed me again here as they were glued in hard and removing it took a lot of force, so I broke one of the housing bolts off. And when removing the adhesive from the chassis the paint came right off too. Thankfully all the damaged area won't be visible later, but whoever did the very limited bodywork on this car needs to have their limbs chopped off piece by piece.   Quite a list if I do say so myself, but a lot of time was spent just discovering new shit that is wrong with the car and finding a solution or parts to fix it. My last problem that I now have the headache of dealing with is that the exhaust studs on the turbo outlets are M10x1.25 threaded, but the previous owner already put on regular M10 nuts so the threads are... weird. I only found this out the hard way. So now I will just try if I can in any way fit the front pipe regardless, if not I'll have to redo the studs with the turbos installed. Lesson learned for the future: Redo ALL studs you put your hands on, especially if they are old and the previous owners were inept maniacs. Thanks for reading if you did, will update when the engine runs again. Hope nothing breaks or leaks and I can do a test drive.
    • No those pads are DBA too  but they have colors too. I look at the and imo the green "street" are the best.
    • I’m not sure what happened I told them about sonic tunes free OTS tune and the next the I know .. I was booted..   To funny 
    • Yea - I mean I've seen my fuel pump which is decades old and uh, while I'm not saying this with real knowledge... but I sure get the ick at using anything in the fuel system that produced the state of that pump. Many years ago I went through multiple pumps (and strainers) before I dropped the tank to clean it out with extreme violence. I'm talking the car would do maybe 50km before coming to a halt, which resulted in me cleaning out the filter with some brake cleaner and going on my way. None of my stuff ever looked like what came out of your fuel tank. I don't think I'd be happy with it unless every single component was replaced (or at least checked/cleaned/confirmed to be clean here).
×
×
  • Create New...