Hey all... I'll say I tried searching before I made this post and didn't find the results I was looking for. Ok here is the issue. I have a Version 4 WRX motor put into my 2000 USDM RS. Since the cold weather has come about here in New England I belive I'm haveing some wonderful detonation issues. This is what I'm experianceing. Under WOT at 4k rpm the car studders heavaly and hear it poping in the exhaust. I loose almost all power untill it gets to about 4.5k-4.8k RPM then it seems to run normal. The motor even seems to run rough through that part of the RPM band. I'm running stock equivelent plugs and 93 oct. fuel. The block has about 80k km on it.

Any Suggestions or other clarifying questions you have please ask or give.

Thanks

 

is it v4wrx jap engine, if so what boost are you running , do you have individual coils and checked them for cracks.

 

the coil pack are all in good shape.. i have inspected those already... as for boost i'll tell you in a couple days.. got a boost gage for the holidays... g/f was wonderful in getting me a boost gage.. but forgot the mounting cup

 

possibly hitting fuel cut due to overboost brought about by the cold weather.
whats the highest octane fuel you can get over there as 93 seems pretty low

 

US 93 is on a par with our 98 isnt it?

 

yep it appears it is, the usa use a mixture of mon and ron to classify their fuel whereas uk and most of europe its just ron

 

yeah.. that is about right.. although it think it's closer to 95 oct... i can get 103 from a loca race shop but that's nearly 2x as much as 93. $2.55/gal for 93 and 103 is $5.32/gal (us dollars)

 

lol, we pay the equivalent of $7.30/gall for that 93 stuff !!

 

WoW!!! maybe that 103 oct stuff isn't that bad.. heh..

 

Ok all .. up date to my delema.. i finnaly got the boost gage installed and i'm running about 13psi/26.5inHg/.8936bar ... thought i'd give a few equivlents too... i seriously doubt it's overbost now... what could be causeing my det. isues

 

i would say it is the fuel octane level i s too low run higher octane run the car for a while on higher octane let the better fuel get run thro the car should make a difference 95 ron is too low get as close to 100 as possible

 

hrm.. might have to get a hold of a local speed shop to get anything close to 100oct... best we normaly can get is 93.. and octane boosters are a joke

 

if it is a jap model it will not run on 93 ron has to be about 100ron we use 98 here sometimes u can get 99 then use some octane boost

 

if it makes u feel better we pay 92 pence a litre here

 

USA 93 octane (not ron) is similar to UK 98 ron

 

Well i finnaly pop'ed a CEL... now questing to go along with my origional post.. would a 31 and 24 cause my issue i have been haveing... 24 is Throttle Position Sensor if that is going bad would that cause my hessitiation/missfire or what ever it is that's happening to umm happen.. *this sentances make little to no sence* .. thanks for you help all