Jump to content
SAU Community

Recommended Posts

Hey guys, recently bought a r34 gtt and I've found when hitting high boost the engine light flahses on and off until i let it off boost.

It has a Z32 and a power FC and is on half a bar of boost.

Previous owner said it is tuned to run on 98 and I put a quarter of a tank of 95 (couldn't find 98 at the time), could this be the issue as the tunes set up for 98? or could it be faulty AFM or something else? I'm scared to put my foot down in boost, don't wanna break anything. >_<

Any help is appreciated :)

Put octane booster or 98 in it before putting your foot down if it's tuned to run 98 its a must I suggest not driving on boost at all as it will be running lean

Edited by Bsa

Your engine is knocking. If its tuned for 98 and you have no other choice but plain old 95, dont push it at all.

If you push it you risk detonation damage to your pistons if it happens for too long.

Engine light flaahing is the pfc telling you its knocking. Do you have a hand controller?

Ty.

+1, your engine is pinging and it is extremely dangerous.

turn the boost down (or even off), don't use full throttle until you have refilled the tank with 98.

If it still pings (light flashing) after a new tank of 98 octane, you need to get the computer re-tuned on a dyno

Just use the hand commander and pull a couple of degrees timing out of it until you can do a complete fill with 98.

Go Settings then Ign/Inj and take some timing out of it.

These temporary changes are deleted as soon as you turn the engine off, all good, tune is unaltered.

That's what this function is for, trial tweaks that can be instantly erased.

.. Going on the assumption that he has a hand controller.

Definately a good band-aid fix for now, thats for sure. Dont wait until you're on empty to put 98 in.. Might as well do it now. You might be diluting the 98, but 96.5 (as an example) octane is better than 95.

+1 what Duncan said. You might as well get it tuned up anyway. Preventative maintenance is always a good thing.

Ty.

Blake using 95 won't make it run lean but 95 has a lower knock resistance.

OP has the engine light ever flashed before with 98 octane?

the engine light can flash due to :

high knock

afm maxing out

injectors maxing out

i doubt on 7psi that the inj or afm are maxing out..

do you have a hand controller?

just bought the car... it's got a boost controller and another gizmo to do with the power fc... it's only on like .6 bar. not sure if it flashed previous... Been driving it around avoiding boost and I'll fill it tomorrow a full tank of 98.... think it has about a quarter on the gauge of 95

will be booking it in for a service next week at chasers n see what they think if the 98 doesn't fix it by then and just drive the daily til then

thanks guys appreciate the help!

Or maybe the previous owner just installed a PowerFC without doing any tuning. The stock ignition map is super aggressive on them.

When he/she said tune, did he or she just poke about with the AFM setting and part of the injection map?

Take the return line off the arse end of the FPR, put a longer hose on te reg, start car and drain into a Jerry. Put the fuel in the daily and fill up with 98.

Job done.

this. unless your patient enough to drive it sedately until empty, which most people arent.

dont use any sort of octane booster, will only cause more trouble.

I wasn't suggesting he use the stock ecu all the time... Just suggesting he try it out to trouble shoot and see if the engine light still comes on under boost. Like trying a different AFM to see if your AFM is stuffed..... Try a different ecu to see if its the tune/ecu or something else. Considering the current owner bought it this way it may help it may not. If he is going to get it re-tuned why not get it tuned on a lesser octane fuel then always use 98 octane?

I wasn't suggesting he use the stock ecu all the time... Just suggesting he try it out to trouble shoot and see if the engine light still comes on under boost. Like trying a different AFM to see if your AFM is stuffed..... Try a different ecu to see if its the tune/ecu or something else. Considering the current owner bought it this way it may help it may not. If he is going to get it re-tuned why not get it tuned on a lesser octane fuel then always use 98 octane?

The stock ecu doesn't flash the engine light when it knocks. I really doubt there is a tune on the ecu. I recon its the stock pfc map. None the less, your car is pinging. Change the fuel or use the hand controller to get rid of some timing.

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

    • Nah - but you won't find anything on dismantling the seats in any such thing anyway.
    • Could be. Could also be that they sit around broken more. To be fair, you almost never see one driving around. I see more R chassis GTRs than the Renault ones.
    • Yeah. Nah. This is why I said My bold for my double emphasis. We're not talking about cars tuned to the edge of det here. We're talking about normal cars. Flame propagation speed and the amount of energy required to ignite the fuel are not significant factors when running at 1500-4000 rpm, and medium to light loads, like nearly every car on the road (except twin cab utes which are driven at 6k and 100% load all the time). There is no shortage of ignition energy available in any petrol engine. If there was, we'd all be in deep shit. The calorific value, on a volume basis, is significantly different, between 98 and 91, and that turns up immediately in consumption numbers. You can see the signal easily if you control for the other variables well enough, and/or collect enough stats. As to not seeing any benefit - we had a couple of EF and EL Falcons in the company fleet back in the late 90s and early 2000s. The EEC IV ECU in those things was particularly good at adding in timing as soon as knock headroom improved, which typically came from putting in some 95 or 98. The responsiveness and power improved noticeably, and the fuel consumption dropped considerably, just from going to 95. Less delta from there to 98 - almost not noticeable, compared to the big differences seen between 91 and 95. Way back in the day, when supermarkets first started selling fuel from their own stations, I did thousands of km in FNQ in a small Toyota. I can't remember if it was a Starlet or an early Yaris. Anyway - the supermarket servos were bringing in cheap fuel from Indonesia, and the other servos were still using locally refined gear. The fuel consumption was typically at least 5%, often as much as 8% worse on the Indo shit, presumably because they had a lot more oxygenated component in the brew, and were probably barely meeting the octane spec. Around the same time or maybe a bit later (like 25 years ago), I could tell the difference between Shell 98 and BP 98, and typically preferred to only use Shell then because the Skyline ran so much better on it. Years later I found the realtionship between them had swapped, as a consequence of yet more refinery closures. So I've only used BP 98 since. Although, I must say that I could not fault the odd tank of United 98 that I've run. It's probably the same stuff. It is also very important to remember that these findings are often dependent on region. With most of the refineries in Oz now dead, there's less variability in local stuff, and he majority of our fuels are not even refined here any more anyway. It probably depends more on which SE Asian refinery is currently cheapest to operate.
    • You don't have an R34 service manual for the body do you? Have found plenty for the engine and drivetrain but nothing else
    • If they can dyno them, get them dyno'd, make sure they're not leaking, and if they look okay on the dyno and are performing relatively well, put them in the car.   If they're leaking oil etc, and you feel so inclined, open them up yourself and see what you can do to fix it. The main thing you're trying to do is replace the parts that perish, like seals. You're not attempting to change the valving. You might even be able to find somewhere that has the Tein parts/rebuild kit if you dig hard.
×
×
  • Create New...