japimports

Could any one Please tell me about the story about Jap imports Impreza engine's Blowing because of using Normal Unleaded fuel. Your only ment to use Super Unleaded. Why does normal unleaded blow the Engine. HELP!!!!!!!!!PLEASE

ozzy

Simply because the jap cars are designed and mapped to run on 100RON fuel. Our Unleaded fuel is only 95RON. Needs to run on at the very least SUL/Optimax at 98RON or ideally you should add some octane booster to increase the quality as close to 100RON as possible.

Other than that you need a specialist to remap the car for the lower fuel quality.

Poor fuel can cause detonation in the cyclinders and quickly blow a hole in them due to bad combustion.

Stefan

caz1562

Well you can talk to me cause I've just experienced this. Had my WRX95 32 months now, always ran on SUL at minimum, then Optimax but never used Octane booster. What I have now is a blown no.4 piston/rings. Engine is currently awaiting removal tonight and then the stripdown will commence. I've learned the hard way IMHO so take note of what fuel you run in the car and what mod's it may carry.

caz1562

John,

Can your magic be worked on my ECU from a 95 WRX with MINES chip ?

john banks

You could still fit water to it yes.

scoobyford

IMHO. Could any one tell me what this is and how it works etc. All the gumph!!!!

ozzy

sorry, do you mean what IMHO is?

It isn't anything, it just stands for In My Humble Opinion.

A "Knocklink" is what AJbasebloke was talking about. Do a quick search and you'll find loads of info on what this is and what it detects.

Stefan

Pete Croney

I could not agree more AJ. UK service schedules were changed to get the running costs down in the fleet tables. If the car is driven by anyone other than Miss Daisy, then this interval is asking for trouble.

I have always thought that someone is having a thoroughly good laugh by naming an ECU after an object that is secreted away and causes an expected explosion, with the intent causing maximum damage

matty01

yeah ,they're taking the micky..

AJbaseBloke

They die because poor fuel does not match the fueling maps done in Japan (which has generally very good fuel). Higher octane fuels are more stable, and therefore are more likely to burn when the spark hits, rather than burn of its own accord out of time (that is det/knock, and puts horrible stresses on engine components). Do it often enough and something breaks. If you have to use NUL, all you can do is try to stay off boost and keep the revs down - without very good ears you won't hear most knock, so a Knocklink can be a real saviour. In the end though, the previous owner could have caused some damage, or just plain old bad luck can see an engine blow. The thing to remember is that far, far more cars are out there driving around without issue, than come on Scoobynet with tales of blown engines (commiserations to those who have suffered, too).

Knocklink - best investment IMHO.

And yes, a remap for UK fuel would not be a bad idea at all.

Also the oil changes are a potential issue IMHO. Following correct procedure is important, but also changing it more often can't hurt I feel. 5000kms is pretty common here in Japan (I personally dunno anyone who runs 10k/kms on a turbo motor between changes, let alone 10k miles), with some who are hard on their cars (and oil) opting for even shorter intervals.

All IMHO, no implied guarantees etc HTH

edit to add: caz1562 brings up good points. the mods, esp if done ***** nilly, can obviously make the situation worse (esp. if fuel quality is poor).

[Edited by AJbaseBloke - 9/10/2003 3:30:24 PM]

john banks

Knocklink and water injection are probably the cheapest safeguards. Mapping will reduce power for the same boost level because you have to run it a bit retarded and richer to stop the det. So you can get back to where you started with a little bonus by mapping plus decat. Improved intercooling also helps with lower octane fuel. Mechanical solution could be thicker headgaskets to lower the compression ratio a tad. Trouble is you lose out on off-boost response.

[Edited by john banks - 9/10/2003 3:35:08 PM]