Jump to content
SAU Community

Recommended Posts

Hey guys- I have recently bought a standard 95 gtst and have been having problems with it having flat spots. I have replaced the plugs and gapped them at 0.8, replaced the coils with splitfires, and changed the fuel filter.

The car is stock with only minor mods exhaust, pod, r34 smic and a turbotech boost controller set at 9 (As low as i could..) The problem was definately worse on the old coils and plugs, and its not popping and spluttering anymore but it still has flat spots under hard acceleration. I have noticed that if i back off slightly as it starts to miss, and continue to feed power in it drives really well.. (Eg driving at 3/4 throttle the car accelerates fine)

I realise these are newbie questions but any help is appreciated.

Cheers

Link to comment
https://www.sau.com.au/forums/topic/350599-r33-gtst-flat-spots/
Share on other sites

hey mate,

i had a few flat spots for a while too. Basically i rekon your timing is abit out. Take to a tuner and get them to run it on the dyno. If the curve dips down then back up then down, or something to that extent i would most definately say its your timing. The tuner should be able to fix it for you.

cheers

Just taking it for a drive and feeding it on in third, i noticed that the flat spots are spot on 3500-4000 then again at 4500-5000. The rest of the rev range is pulling really hard. I dont know if i mentioned i am using plugs that are pfr511g. I have gapped them to 0.8 but i have noticed that the other guys on here seem to go with the bcpr6es plugs, so i figure thats my next point of call, hopefully not the ecu!!

I have spoken to a tuner (toshi in sydney) and he said that it would be the computer detecting somesort of overboost and that when he remaps the ecu it will be solved. Its a bit of a bummer cause i cant afford the tune for a while. I also tried taking off the boost controller and running the stock t piece, but it still makes around 10-11 pound of boost anyway, and the problem is still there. I think toshi is definately my next priority.

It would be more so airflow in excess of expected and the ecu will be most likely chucking fuel and taking timid out of it. And as said when it hits the point where VCT switches off it's dying

R33's dont have boost sensing to the ecu so it will be your AFM saying WTF :)

If he's doing a remap it should fix your problem but you should probably go to the spark plugs you mentioned above as well

In my r32 I was running copper plugs bkr6e then went bcpr6es and had flat spots all thru the rev range I doing think changing your ecu will do anything get it to tuner check timing and afr thats the easyiest and less cost effective way to sort the issue out don't take this negatively but I'm speaking from experience

from what your describing ive had a similiar problem, same thing happened when the boost was set to 10psi, going up through 2nd or 3rd, then in the higher rev range would noticeably *stall* in power. apparently was to do with the stock ecu freaking out and dumping fuel at that moment, or rich and retard they call it

anyway i upgraded the ecu in the end and got it dyno tuned. smooth as silk now.

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

    • No, code 21 is very straightforward. It can only be the things described in that diagnostic flow. In fact it has no way of knowing that the spark plug resistance is out of spec.
    • Hi, SteveL Thank you very much for your reply, you seem to be the only person on the net who has come up with a definitive answer for which I am grateful. The "Leak" was more by way of wet bubbles when the pedal was depressed hard by a buddy while trying to gey a decent pedal when bleeding the system having fitted the rebuilt BM50 back in the car, which now makes perfect sense. A bit of a shame having just rebuilt my BM50, I did not touch the proportioning valve side of things, the BM50 was leaking from the primary piston seal and fluid was running down the the Brake booster hence the need to rebuild, I had never noticed any fluid leaking from that hole previously it only started when I refitted it to the car. The brake lines in the photo are "Kunifer" which is a Copper/Nickel alloy brake pipe, but are only the ones I use to bench bleed Master cylinders, they are perfectly legal to use on vehicles here in the UK, however the lines on the car are PVF coated steel. Thanks again for clearing this up for me, a purchase of a new BMC appears to be on the cards, I have been looking at various options in case my BM50 was not repairable and have looked at the HFM BM57 which I understand is manufactured in Australia.  
    • Well the install is officially done. Filled with fluid and bled it today, but didn't get a chance to take it on a test drive. I'll throw some final pics of the lines and whatnot but you can definitely install a DMAX rack in an R33 with pretty minor mods. I think the only other thing I had to do that isn't documented here is grind a bit of the larger banjo fitting to get it to clear since the banjos are grouped much tighter on the DMAX rack. Also the dust boots from a R33 do not fit either fyi, so if you end up doing this install for whatever reason you'll need to grab those too. One caveat with buying the S15 dust boots however is that the clamps are too small to fit on the R33 inner tie rod since they're much thicker so keep the old clamps around. The boots also twist a bit when adjusting toe but it's not a big deal. No issues or leaks so far, steering feels good and it looks like there's a bit more lock now than I had before. Getting an alignment on Saturday so I'll see how it feels then but seems like it'll be good to go       
×
×
  • Create New...