adamsaiyad
09-10-2010, 03:49 PM
Hello members.
I am from a small country called zimbabwe in africa.
this is the second subaru legacy that i have owned.
These are some of the best cars i have come across, sadly the first legacy i owned was a 2000 model and a b4 also twin turbo.
keeping in mind the first legacy was in worse condition and less powerfull then this 2002 model i have purchased.
The problem i am having is massive detonation.
Im not sure how adaptive the ecu is to poor fuel and i would like to ask what would happen if i was to run a poor grade fuel like 92 octane fuel would it cause the type of detonation im experiencing.
The car drives well and has 124 000kms on it.
I have tried the following.
Replaced fuel filter.
Changed plug gap from 1mm to 0.65mm on all plugs
Serviced and replaced oil with castrol edge 10w-60 cause temps here are quite high average 28 degrees celcius.
Now i have tried adding toluene as a octane booster at a 30% concentration to up the octane an average of 4 points to 95 octane +-
this hasnt helped.
The car is otherwise stock and has heat range 7 plugs factory spec.
exhaust is standard with catalytic convertors still in place.
Ive changed fuel pump as well and tested still have the detonation.
it comes when accelerating at about 3000rpm and can be heard as marbles in a can type noise.
Funny thing is when i drive at a constant 120km/hr and then pull into a suburb and drive around the detonation goes away until heat soak takes place again and bang the det is bang again crackling away.
Eating away at a perfect engine isnt what i want and i would like some advice.
Should i up the fuel pressure to try and curb it ?? of course this would mean running slightly rich ?
Should i get a aftermarket ecu and re map?
Should i get a Afr controller and just map fuel or should i worry about retarding timing as well?
Is there anything else i should be looking at changing or cleaning ?
I have also cleaned out the maf sensor as well with some carb cleaner safe for air flow meters ?
Should i place a bigger hood scoop to try lower intake temps ?
Should i fit a racing air filter as my last car had this and performed ok with out problems of det?
keeping in mind that i dont have access to a dyno here and mapping would have to be on a trial error basis by myself if i was to fit a greddy emanage ?
The fuel we get here sadly inst great and i have the car and dont want to sell it .
I have also owned two wrxs as well and they havent ever had det?
Should i replace the knock sensor ?
or replace the Oxygen sensor as well ?
should this car be adapative to bad fuel ?
What other mechanical methods should i be chasing to try and lower detonation im really stuck ?
driving her like miss daisy to try and not break the engine ?
On a side note the exhaust valve at the rear silencer was stuck and the cable snapped that opens and closes the arm for the rear flap so ive bolted it open in the hope that back pressure was causing the egt's to rise ?
Do these cars have a egt recirc valve that i need to check and if so where is it located?
Hope to hear from you all soon desperate to try and solve this ?
Cheers
adam
Africa Zimbabwe
I am from a small country called zimbabwe in africa.
this is the second subaru legacy that i have owned.
These are some of the best cars i have come across, sadly the first legacy i owned was a 2000 model and a b4 also twin turbo.
keeping in mind the first legacy was in worse condition and less powerfull then this 2002 model i have purchased.
The problem i am having is massive detonation.
Im not sure how adaptive the ecu is to poor fuel and i would like to ask what would happen if i was to run a poor grade fuel like 92 octane fuel would it cause the type of detonation im experiencing.
The car drives well and has 124 000kms on it.
I have tried the following.
Replaced fuel filter.
Changed plug gap from 1mm to 0.65mm on all plugs
Serviced and replaced oil with castrol edge 10w-60 cause temps here are quite high average 28 degrees celcius.
Now i have tried adding toluene as a octane booster at a 30% concentration to up the octane an average of 4 points to 95 octane +-
this hasnt helped.
The car is otherwise stock and has heat range 7 plugs factory spec.
exhaust is standard with catalytic convertors still in place.
Ive changed fuel pump as well and tested still have the detonation.
it comes when accelerating at about 3000rpm and can be heard as marbles in a can type noise.
Funny thing is when i drive at a constant 120km/hr and then pull into a suburb and drive around the detonation goes away until heat soak takes place again and bang the det is bang again crackling away.
Eating away at a perfect engine isnt what i want and i would like some advice.
Should i up the fuel pressure to try and curb it ?? of course this would mean running slightly rich ?
Should i get a aftermarket ecu and re map?
Should i get a Afr controller and just map fuel or should i worry about retarding timing as well?
Is there anything else i should be looking at changing or cleaning ?
I have also cleaned out the maf sensor as well with some carb cleaner safe for air flow meters ?
Should i place a bigger hood scoop to try lower intake temps ?
Should i fit a racing air filter as my last car had this and performed ok with out problems of det?
keeping in mind that i dont have access to a dyno here and mapping would have to be on a trial error basis by myself if i was to fit a greddy emanage ?
The fuel we get here sadly inst great and i have the car and dont want to sell it .
I have also owned two wrxs as well and they havent ever had det?
Should i replace the knock sensor ?
or replace the Oxygen sensor as well ?
should this car be adapative to bad fuel ?
What other mechanical methods should i be chasing to try and lower detonation im really stuck ?
driving her like miss daisy to try and not break the engine ?
On a side note the exhaust valve at the rear silencer was stuck and the cable snapped that opens and closes the arm for the rear flap so ive bolted it open in the hope that back pressure was causing the egt's to rise ?
Do these cars have a egt recirc valve that i need to check and if so where is it located?
Hope to hear from you all soon desperate to try and solve this ?
Cheers
adam
Africa Zimbabwe