Jump to content
SAU Community

Car Running Too Powerful And Jerking

kiz_baby

By kiz_baby,
in Engines & Forced Induction

 Share

Recommended Posts

kiz_baby Apprentice

kiz_baby

Posted
Posted

Hi,

Wondering if someone can give me an idea as to what is wrong with my car. It's an auto R33 GTST with an AVCR Boost controller. When flooring the car it is cutting out for a split second at around 3500 revs.

I have checked and changed the air flow meter but still experiencing the same issue. My car normally runs at a maximum boost of about 0.75 bar or 0.82 in the cold when travelling upto 100km/h.

It is now achieving upto 1.07 bar at only 50km/h.

Awesome that it's so powerful right now but not so good that it's cutting out/jerking when putting my foot down.

Any ideas?

  • Nope 1
89CAL Grand Master

89CAL

Posted
Posted

I don't think the stock AFM would max out that early. Hes probably seeing 210rwkw at the most on stock ecu (if it is stock ecu)

The afm is not maxing out. It is seeing abnormal air flow and putting the car into fuel cut or R&R which is causing the miss. There is a difference between maxing out the afm and what is happening here. Wind the boost down. 14psi is to much for a stock turbo and you may not see stable performance till you drop it to about 8psi

The Mafia Grand Master

The Mafia

Posted
Posted (edited)

actually, the stock AFM maxes out at about 180rwkw. I usually tune around it. And the factory ECU cannot do 210rwkw. A tuned Powerfc can. A stock ECU with 10psi can make about 160-170rwkw. WIth rich and retard hitting, about 100rwkw at 12psi+

Your boost is too high. This is clear and simple.

With the factory ECU, Your car is hitting a rich and retard mechanism. This is your car telling you there is something wrong with the boost and to fix it. It is causing your car to cut out and do shit like that because its trying to stop you from blowing your engine and turbo.

Wind to boost back to 10psi and your problems will go away. If not 10, then try 9. DO you even have an after market intercooler?

This sounds exactly like the problem. 15psi is WAY too much for a stock turbo on a standard engine. You will blow it, turbo AND motor if you persist.

Edited by The Mafia
Andrewtler Contributor

Andrewtler

Posted
Posted

I been running seemingly fine on mine mate. I also use the avcr and I max mine at 0.8 of a bar. If you don't have spitfire coilpacks it will cause this problem on most occasions as it is a known problem for r33s. Either way the only reason I run miner like this is because I'm waiting for my upgrade to be shipped to me so i don't care if my turbo blows up because I heard it only the exhaust side. Stick with the safe level of 10 psi I know it's hard to go backwards in performance but unless you got cash to splurge I'd do it. I think from memory 10 psi is approx 0.7 bar at around 50% duty cycle ;)

SECURITY Grand Master

SECURITY

Posted
Posted

when i was doing some data logging a while ago i noticed that the AFM causes R&R at two points. once if you hit ~3.8v @ 3600rpm and again if you're at ~4.5v @ 5000rpm or thereabouts. too much airflow through your AFM causes it to do what you are experiencing, not coil packs.

luvpsi Mentor

luvpsi

Posted
Posted

when i was doing some data logging a while ago i noticed that the AFM causes R&R at two points. once if you hit ~3.8v @ 3600rpm and again if you're at ~4.5v @ 5000rpm or thereabouts. too much airflow through your AFM causes it to do what you are experiencing, not coil packs.

yeah i ahve heard coil packs are good for up to 300rwkw on a series 2 r33. i beleive it would be fuel cut due to running to much boost on a stock ecu all i can suggest is lower the boost to 10psi at the most do not go over 10psi if you had an aftermarket ecu you would be able to prob sit at 12psi comfortably but with stock ecu no chance

Andrewtler Contributor

Andrewtler

Posted
Posted (edited)

when i was doing some data logging a while ago i noticed that the AFM causes R&R at two points. once if you hit ~3.8v @ 3600rpm and again if you're at ~4.5v @ 5000rpm or thereabouts. too much airflow through your AFM causes it to do what you are experiencing, not coil packs.

I was having this exact problem in my late series 1.5 r33. I changed my coilpacks to the splitfire option and not only was the problem solved but I could run even more boost. I do think I'll drop my boost back though cause I'm a bit scared of detonation at the moment as I have done a fair few mods and haven't installed my power fc yet

Edited by Andrewtler
R31Nismoid Grand Master

R31Nismoid

Posted
Posted

yeah i ahve heard coil packs are good for up to 300rwkw on a series 2 r33. i beleive it would be fuel cut due to running to much boost on a stock ecu all i can suggest is lower the boost to 10psi at the most do not go over 10psi if you had an aftermarket ecu you would be able to prob sit at 12psi comfortably but with stock ecu no chance

Stock coil packs are good for over 400rwkw without a problem if they are in working order. Same as splitfires, just more expensive.

It's the ignition amp that lets them down, not the coil itself. (aka: HKS DLI)

  • Like 1
SargeRX8 Grand Master

SargeRX8

Posted
Posted

People expect too much from their cars without spending. Spend at least $700 - $2000 on an ECU and tune and run your stock components to get power. You can get free performance to an extent.

Its not coil packs. My old r33 was making 240rwkw with 17psi and using std coils, as others have said. Your ECU is responding to the extra air.

kiz_baby Apprentice

kiz_baby

Posted
  • Author
Posted (edited)

Thanks for the info. I'm running a stock ECU and yes I do have an aftermarket Apexi intercooler.

I can hear the air being sucked into the car as if I had a pod filter (I'm running a K&N panel filter) and the stock BOV is making sounds like an aftermarket model.

What would cause more increased airflow to the car? Oh and by the way I've turned off the AVC-R and still experiencing the same problem.

Edited by kiz_baby
R31Nismoid Grand Master

R31Nismoid

Posted
Posted

R&R can kick in @ 9psi, it can not kick in till 14psi

That are FAR too many variables. Load, temp, airflow... Even accuracy of the boost gauge - all are factors mate.

There is not "magical" sweet spot.

IF you go back to 8psi and the problem is fixed - its quite simply ECU time.

  • Like 1
SECURITY Grand Master

SECURITY

Posted
Posted

Turning off the boost controller won't do anything except leave your boost levels unmonitored.

If you run a line direct from your wastegate actuator to your cooler piping it should sit at around 8-10psi. Check if this fixes your problem but keep an eye on boost levels at the same time, as well as how your vacuum hoses were connected to your avcr.

Galois Veteran

Galois

Posted
Posted

Coilpacks can fail at stock boost, I know, it happened to me. The nissan coilpacks are regarded by many as the best ones available. Think about it, cars being thrashed for 10-20 years so things will eventually start to go. But the point is they do go.

So if you're having ignition problems with ignition and you still have original coilpacks they're either the source of the problem, contributing, or planning a future problem for you.

They're also a relatively cheap fix, yellow jackets are $400 with a 2 year warranty, and everyone seems to say aftermarket coilpacks are a great upgrade.

SargeRX8 Grand Master

SargeRX8

Posted
Posted

I just experienced something interesting and scary. Installed my boost controller today and got it set for 8psi. It fell off the mount and I was unaware my foot was touching the dial. I gave it a little hit and it took off like never before then the power vanished at about 5krpm. I pulled over straight away and my settings screwed up and I managed to hit 14.7 psi accudently, on a stock turbo and ecu. I shit in my pants and just let the car idle for a few mins to cool down. I get my new tuned ecu this coming week hopefully. Tuned for 10psi on stock everything apart from exhaust and fmic. With a good safe tune, 10psi and stock turbo should see around 180 - 190rwkw.

  • 3 months later...
89CAL Grand Master

89CAL

Posted
Posted

boost cut

Not boost cut....... The ECU does NOT see boost in an R33 GTS-t.

The ECU see's air flow, Injector duty etc etc. See's variables out of its programmed range and throws fuel at it and takes timing out

You can not call this boost cut

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • oHBoy.
      Starter motor replacment teeth count.

      By oHBoy. · Posted

      I had 3 counts over the last couple of weeks once where i got stranded at a jdm paint yard booking in some work. 2nd time was moving the car into the drive way for the inspection and the 3rd was during the inspection for the co2 leak test. Fix: 1st, car off for a hour and half disconnected battery 10mins 4th try car started 2nd, 5th try started 3rd, countless time starting disconnected battery dude was under the hood listening to the starting sequence fuel pump ect.   
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      This. As for your options - I suggest remote mounting the Nissan sensor further away on a length of steel tube. That tube to have a loop in it to handle vibration, etc etc. You will need to either put a tee and a bleed fitting near the sensor, or crack the fitting at the sensor to bleed it full of oil when you first set it up, otherwise you won't get the line filled. But this is a small problem. Just needs enough access to get it done.
    • suko
      J50 clock date suddenly reset to January 1

      By suko · Posted

      The time is always correct. Only the date is wrong. It currently thinks it is January 19. Tomorrow it will say it is January 20. The date and time are ( should be ! ) retrieved from the GPS navigation system.
    • MBS206
      Mistakes were made, my R34 Story

      By MBS206 · Posted

      Buy yourself a set of easy outs. See if they will get a good bite in and unthread it.   Very very lucky the whole sender didn't let go while on the track and cost you a motor!
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      Well GTSBoy, prepare yourself further. I did a track day with 1/2 a day prep on Friday, inpromptu. The good news is that I got home, and didn't drive the car into a wall. Everything seemed mostly okay. The car was even a little faster than it was last time. I also got to get some good datalog data too. I also noticed a tiny bit of knock which was (luckily?) recorded. All I know is the knock sensors got recalibrated.... and are notorious for false knock. So I don't know if they are too sensitive, not sensitive enough... or some other third option. But I reduced timing anyway. It wasn't every pull through the session either. Think along the lines of -1 degree of timing for say, three instances while at the top of 4th in a 20 minute all-hot-lap session. Unfortunately at the end of session 2... I noticed a little oil. I borrowed some jack stands and a jack and took a look under there, but as is often the case, messing around with it kinda half cleaned it up, it was not conclusive where it was coming from. I decided to give it another go and see how it was. The amount of oil was maybe one/two small drops. I did another 20 minute session and car went well, and I was just starting to get into it and not be terrified of driving on track. I pulled over and checked in the pits and saw this: This is where I called it, packed up and went home as I live ~20 min from the track with a VERY VERY CLOSE EYE on Oil Pressure on the way home. The volume wasn't much but you never know. I checked it today when I had my own space/tools/time to find out what was going on, wanted to clean it up, run the car and see if any of the fittings from around the oil filter were causing it. I have like.. 5 fittings there, so I suspected one was (hopefully?) the culprit. It became immediately apparent as soon as I looked around more closely. 795d266d-a034-4b8c-89c9-d83860f5d00a.mp4       This is the R34 GTT oil sender connected via an adapter to an oil cooler block I have installed which runs AN lines to my cooler (and back). There's also an oil temp sensor on top.  Just after that video, I attempted to unthread the sensor to see if it's loose/worn and it disintegrated in my hand. So yes. I am glad I noticed that oil because it would appear that complete and utter catastrophic engine failure was about 1 second of engine runtime away. I did try to drill the fitting out, and only succeeded in drilling the middle hole much larger and now there's a... smooth hole in there with what looks like a damn sleeve still incredibly tight in there. Not really sure how to proceed from here. My options: 1) Find someone who can remove the stuck fitting, and use a steel adapter so it won't fatigue? (Female BSPT for the R34 sender to 1/8NPT male - HARD to find). IF it isn't possible to remove - Buy a new block ($320) and have someone tap a new 1/8NPT in the top of it ($????) and hope the steel adapter works better. 2) Buy a new block and give up on the OEM pressure sender for the dash entirely, and use the supplied 1/8 NPT for the oil temp sender. Having the oil pressure read 0 in the dash with the warning lamp will give me a lot of anxiety driving around. I do have the actual GM sensor/sender working, but it needs OBD2 as a gauge. If I'm datalogging I don't actually have a readout of what the gauge is currently displaying. 3) Other? Find a new location for the OEM sender? Though I don't know of anywhere that will work. I also don't know if a steel adapter is actually functionally smart here. It's clearly leveraged itself through vibration of the motor and snapped in half. This doesn't seem like a setup a smart person would replicate given the weight of the OEM sender. Still pretty happy being lucky for once and seeing this at the absolute last moment before bye bye motor in a big way, even if an adapter is apparently 6 weeks+ delivery and I have no way to free the current stuck/potentially destroyed threads in the current oil block.
×
×
  • Create New...