Wilksey

Hi,

I'm hoping someone can advise me on a feature / problem on my V3 STi JDM.

Apparently it was imported running at 335+ bhp, it certainly feels quick when flooring it, however, it still has the 180kph limit on for now.

I have had the car approx 3 weeks, at first I thought the limiter was kicking in around 150/ 160 kph, but today I progressively put my foot down and it hit 180kph but when I floor it in 3rd or 4th gear the car seems to just jerk and slow down at 150/160, then it will pick back up again.

I think its the turbo pressure cutting out because the turbo guage (it looks like a standard one) hits the end of the range when it does the aforementioned "jerking".

So if I drive it slow-ish it is fine to 180kph, but when I floor it, at around 150/160 kph it feels like the fuel is cutting off and slows down.

Does anybody have ANY idea what is happening and why?

Sorry for the long post, and thank you in advance, first Scooby and loving it!

SqeekyMclean

sounds like you enjoy screwing it

Wilksey

I've only floored it twice, not even to redline, around 6500/7000 rpm.

It was like it when I got the car.

So any idea what it could be?

It can go as little as 4500/5000 rpm when it does it.

I haven't driven it "hard" I don't go round bouncing off the rev limiter in every gear, I dont know what the prev owner drove it like.

Apparently it has a bigger turbo and remapped ECU which was done in Japan.

Just looking for some sensible advice.

Wilksey

Forgive my ignorance, but I have had a thought, I am running 95 RON fuel, could it be that because Japanese fuel is 100 RON (Correct me if i am wrong on this) that when the turbo has a sudden boost of air at high pressure and because the fuel isn't burning as efficiently as 100 RON that the mixture is running lean and choking the engine with air?

I know the sensors etc are supposed to control this to ms resolution but just a thought.

I have run naturally aspirated jap imports on 95 fine, but they dont operate the same as ones with blowers.

SqeekyMclean

V power or tesco 99 needed fellow scooby laddy....

Ant

no no no no dont run your import on 95 ron thats the first mistake, but my mate had a starlet import and his did the same thing with his limiter on.

Wilksey

Thanks for you replies,
I am having the limiter taken off (well converted to MPH which apparently moves the limiter to 180mph), as soon as I can find a decent place as its a cable delimiter on the V3 STi apparently, and I dont want to take the dash apart myself, I dont have the time or the manuals to do so.

I just need confirmation that my car isn't broken! I will fill it up with vpower as we dont have a close tesco petrol station where I live.

It will boost fine progressively but a foot down will make it "choke", i'm hoping the turbo is fine, as it does boost very well before and after.

If i'm doing around 160kph and then toe it to 180kph (which be fair, 112 mph isn't exactly booting a Scooby my old old old old vauxhall nova used to go 115mph, downhill) but it will hit the limiter and give up at 180 with no more interruptions.

It scared the **** out of me the first time it did it, but I have never owned a petrol import turbo before with all the limiters etc.
I am just hoping someone has had the same thing happen and it is just a fuel octane issue or something simple.

rbaz

iTrader: (1)

I wouldn't worry about the turbo it’s the crank I would be worried about.
Running it on 95 Ron fuel will be causing it to knock which will over time damage the crank bearings or the pistons especially if it over boosting. Its a very common failure don’t use any boost until you have filled up with Power Tesco 99 etc or get some octane booster.
It may not be the cause of the current problem (but it will cause a major failure) sounds like it is over boosting. STI V3 doesn't have a standard boost gauge what PSI/bar is the boost reaching on the gauge?

jaytc2003

iTrader: (1)

sounds like fuel cut.

Personally though, I would see what ecu you have in the car, and maybe think about either getting it remapped (if ossible depending on ecu) or get a replacement ecu. If it was remapped in japan with a bigger turbo then I dont think it will last long on 95 ron fuel, I would even be careful booting it with v power and octane booster. Just my opinion of course

jaytc2003

iTrader: (1)

and to add to my last post, the top mount intercooler isnt very efficient at the speeds you are talking about, so hot air in the engine along with poor fuel (how poor depends on the japanese map which generally they are quite aggressive) = something expensive waiting to happen

Wilksey

Do the STI V3 not come as standard with a guage? It looks original, sticking out of the cowling by the wiper stalk, i.e. it doesn't look cut out.
RE: the fuel, I'm not sure if Japan has any "high octane" fuel, I know their standard is 100 RON, or it used to be anyway.
The car has been run on V-POWER since it was imported until I got my hands on it and I know, stupid mistake.
I think the guage goes to 1.5?

jaytc2003

iTrader: (1)

No gauge as standard.

I would check the ecu in the passenger footwell to see what ecu it is. It may have a sticker saying "MINES" or maybe something else. The mines ecu's run an aggressive map, so coupled with overboost, high speeds, and poor fuel, you have all the right ingredients for a big bill

Skoobie Dhu

iTrader: (3)

Wilksey, I've had my V3 for 10 years now. It's standard except for a full decat exhaust and k&n. When I bought the car, the garage had just done a service and changed the oil. They put in too much oil and I ended up with oil vapours getting into the boost solenoid. It would cut out very sharply when accelerating hard - bit like hitting a brick wall. I dropped out about half a litre of oil and cleaned the solenoid with solvent. Check the oil level, should be half way between the half full and full marks.
Do a search on here on the boost solenoid - common problem in early STi's.

My car made 326 bhp @ 7,500 rpm - the V3 likes to rev

p.s the delimiter on the v3 fits into the speedo cable under the bonnet - 10 min job to fit.

p.p.s. when you say a 'bigger turbo', it's worth seeing if you can see which kind of turbo. The v3 had the biggest turbo of all the versions (v4 might be same) it's maybe just a figure of speech and it's the standard turbo fitted albeit a 'bigger turbo'.
I wouldn't worry too much about short term use of 95 ron in a v3 - PM me and I'll explain. Not going to mention why here or it'll wake the usual 'world will end' doomsters