Jump to content
SAU Community

Recommended Posts

Hey everyone

Well i had a tune a while back on my car using an Safc/avcr and when i drive it and hit full boost it shows my boost hits 0.77 bar and goes all the way up to 0.90 bar, yesterday i was bored so just scrolled through the settings and noticed learn gear was on so i disabled it, as I’ve heard learn gear causes the boost to change a bit and doesn’t give constant boost? Secondly i went into my boost/duty cycle menu on my avcr and the boost was set on 0.75 bar, so i thought ill try put it to 0.8 bar.. then i took it for a drive, when i full boost it held at 0.8bar but when i hit about 5000rpm it went to 0.90 bar and it kind of sounded like it was hitting a fuel cut or some limp mode on the stock ecu so i stopped straight away.

i wound it back to 0.75 and again noticed it holds at 0.75-0.77 bar under 5000rpm then it reaches 0.88 bar above 5000rpm ( i set my avcr so it shows the highest number)..

Later on i was driving home and i had a query as i have a Apexi Safc 2 also. i noticed my fuel/air ratio on idle is at 5.8%, when i start spooling and hit boost under 5000rpm stays at approx 0.9% after 5000rpm or upper area of the rpm range it goes to 0.1%..

To help a bit more my car is a R32 gtst with the following:

Rb25det S2 engine conversion

Stock turbo

Stock ecu

Stock injectors

Straight through exhaust

Pod

R32 Gtr fuel pump

Apexi AVCR

Apexi SAFC

I just have a few questions first being is my car leaning out? Secondly if so could it be because of the R32 gtr pump or another issue?, does anyone know if having VCT can throw off the AVCR that much?

Thanks guys

Ni

Link to comment
https://www.sau.com.au/forums/topic/318631-whats-up-with-my-car/
Share on other sites

if you got your car tuned on a dyno it should be running good, first point of call i would consult the guy who tuned it.

secondly it sounds like u need to read into how to use the AVCR a little as i think you have your gain/duty set wrong to help you achieve target boost properly.

if you got your car tuned on a dyno it should be running good, first point of call i would consult the guy who tuned it.

secondly it sounds like u need to read into how to use the AVCR a little as i think you have your gain/duty set wrong to help you achieve target boost properly.

hey man, yer just downloaded the pdf for the AVCR now

quote

(it kind of sounded like it was hitting a fuel cut or some limp mode)

fuel cut is a big bang (some times) and a sudden loss of power

i doubt it was this

i think you would have been hearing abit of missing (pop pop pop)

if this is the case get your self some new spark plugs gap them to 0.8mm (or buy them pre-gaped)

wind you boost back up!

if it goes pop pop pop again, you have two options.

keep you boost low enough so it doesn't miss

OR

get your self some new coil packs

i use splitfire but there are a few brands most have been covered so do a search.

  • 2 weeks later...
quote

(it kind of sounded like it was hitting a fuel cut or some limp mode)

fuel cut is a big bang (some times) and a sudden loss of power

i doubt it was this

i think you would have been hearing abit of missing (pop pop pop)

if this is the case get your self some new spark plugs gap them to 0.8mm (or buy them pre-gaped)

wind you boost back up!

if it goes pop pop pop again, you have two options.

keep you boost low enough so it doesn't miss

OR

get your self some new coil packs

i use splitfire but there are a few brands most have been covered so do a search.

hey man, ah good to know it wasn’t a fuel cut then.. and yer i had changed my spark plugs recently so that wasn’t the problem either, however i found out it was my SAFC so all is good :)

hey i have the same problem with my car its a r32 gtst with the rb25det cant cant find out the problem. if u can help me thx.

hey man, for me it ended up being my SAFC that was set up wrong so i used my friends SAFC settings with the SAME mods as my car, and now the car runs great and it reads the proper way by the fuel/air ratio % actually increasing instead of the other way around..

Good luck man, Ni

Good luck man, Ni

Sounds like you need to adjust/reduce the duty a few % in the 5k rpm range

Because as you say the learn gear was on and it would have changed the boost map.

hey man

yep i turned of learn gear and put the duty down a bit, i think it was my SAFC that was the problem

i am useing a series 2 ecu on a series 1 engine u guys think that could be the problem? and my maf is the rb20det one form the old engine?

hey man

not to sure, but do you mean AFM? not maf? anyways that could be one problem, secondly try plugging in a S1 ecu, i dont see the point of having a s2 ecu if you dont have a Series 2 motor..

ok i will try 2 do all of those things. but this what the car dose it pulls out good but when i hit around the 5000 rpm's it its hiting a fuel or a boost cut i dont know what it is

and it missfires sometimes it sound like pop pop pop and the rpm drops too 0 and the car turns off some times.

ok i will try 2 do all of those things. but this what the car dose it pulls out good but when i hit around the 5000 rpm's it its hiting a fuel or a boost cut i dont know what it is

and it missfires sometimes it sound like pop pop pop and the rpm drops too 0 and the car turns off some times.

hey bro if you mean its hell loud pops and your car starts to jerk i had the same problem and mine was the crank angle sensor plug had a broken clip and had come of slightly and wasn’t making full connection

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

    • Thanks Dose.....    I appreciate it!!
    • I'll probably be putting the shit box back on the dyno again soon, I want to dial in the closed loop boost control properly. I'll have a camera facing the car/motor for fun too. Just note, there are essentially 3x 10AN inlets going into the catch can and 1x going back to the intake pipe. Most of the time the catch can "return" to the sump actually is the crank case breather, pushing air out.
    • I have the R3C with a Nismo slave and by no means does it behave like a stocker, it ain’t THAT bad. On take off just give a bit more throttle than you would say a coppermix and it’s fine. It will not slip though.   
    • Okay. Final round of testing done. Got a friend to hook up a fancy scanner to the car and we also ran some compression and leakdown tests, she is healthy.  The MAF was definitely the culprit. So for future reference anyone with similar issues that find this thread. I suggest the following steps, in order of affordability:   Check your spark plugs for any fouling, replace plugs if they are bad or re adjust the gaps making it narrower (0.8mm would be good). Check every coil's resistance with a multimeter. It can be done by probing the IB and G pins on the coil pack. Resistance should be around 1.4 (+/- 0.1) Ohms Check the MAF. If you have Nissan connect or a good scanner with the 14 adapter it should allow you to see the voltage on the MAF reading should be around 1.1 - 1.2V when car is idling. But if you don't, buy a new MAF from Amazon and test, then return it. (For instance, I got a Chinese one for $40 that was reporting 1.3v on idle). If you still have scanner, you can run tests on the injectors to see if they are working, just remember to unplug the fuel pump fuse/relay and have no pressure on the line. Then listen for the noises that the injectors make. Clean/replace injectors as needed. Once you find the issue and fix, order thousands of dollars worth of OEM parts to refresh unrelated things (Optional)   PS: Thanks to the absolute legends of this forum for the responses and help to someone that went a bit over their head. (me)
    • Ha ha ha, so they stopped the bearings spinning on the one you want, but then decided the crank hub should slip instead 😛   Stick to RB, at least you can work on it yourself. And now it doesn't smell of vapour   Also I still believe there's a chance your new flap doesn't "pop", as even though the engine might breath hard, it has a direct path with no restriction to the inlet, which when on boost should pull a bit of suction for you. If you do get pressure in the catch can id be very intrigued. Time to put a boost gauge on it, and a session at the track, then solid cover your vent and do another session
×
×
  • Create New...