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VVti detonation - PLEASE HELP


Guest [S]oLiD

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Guest [S]oLiD

Hi guys,

 

i need some help or advice PLEASE:

 

i own a jspec 98 TT vvti and am experiencing what "sounds" like detonation at the 2800 - 3000 rpm mark... It makes the sound when its NOT under load and before full boost occurs..

 

my car is almost stock, its has a FMIC, cat back exhaust and its runnin stock boost levels...

 

it doesnt make sense for it to be detonating but it sounds awfully like it...

 

will a stock car with a FMIC and catback detonate???

 

any help or advice would be greatly apreciated..

 

thanks

 

Sam

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what boost level are you running?

what are your plugs like? these usually show signs of dett before you can tell

what pugs do you have in there?

have you tried to pull the error codes, i am 100% sure the ecu would log it it logs every thing else lol:D

Click Here

 

you can have 2 identical engine one will dett and the other wont, every engine is different the only way to know it so have it checked by a pro, if it is dett it has to be fixed anyway, i understand the 2jz can put up with dett longer than most engines but it will still break

 

EDIT: :welcome:

Edited by TurboBrett (see edit history)
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I have had this, could find no cause, and no fault codes. A new AFM unit helped, but didn't entirely cure. I later found the blades on the front turbo compressor were damaged, but couldn't link the problems in my head. the car was then sold and went single turbo. car also had sporadic FBW throttle issues.

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I would be very surprised if it was detonation, the only way i can think of that occurring is if the is an AFM fault where the ECU is seeing to low voltage, are you sure its not a plug/coil pack causing misfire? can you also be more specific as to just what sort of load its happening at.

Edited by Tricky-Ricky (see edit history)
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Guest [S]oLiD
I have had this, could find no cause, and no fault codes. A new AFM unit helped, but didn't entirely cure. I later found the blades on the front turbo compressor were damaged, but couldn't link the problems in my head. the car was then sold and went single turbo. car also had sporadic FBW throttle issues.

 

chris, did the detonation stop once he went single ???

 

any ideas??

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Guest [S]oLiD
I would be very surprised if it was detonation, the only way i can think of that occurring is if the is an AFM fault where the ECU is seeing to low voltage, are you sure its not a plug/coil pack causing misfire? can you also be more specific as to just what sort of load its happening at.

 

it happens under light load, between the 2800-3000 rpm rev range..

 

it make the sound whilst driving on a flat road or even down hill, so its not under heavy load, i thought detonation only took place under load???

 

if it were the plugs/coilpacks, wouldnt it misfire or detonate randomly and not only within that specific rev range???

 

im baffled, this whole thing makes no sense...

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Guest [S]oLiD

its really starting to concern me, i dont want to destroy my engine..

 

it makes the sound between the 2800-3000rpm rev range only

 

doesnt have to be under load for it to make it, it makes it a half throttle goin on flat roads or even down hill.. I thought detonation only takes place under load ????

 

could it be a timing issue ??? could it be a heat/cooling issue ???

 

the car is almost stock, standard boost levels with a FMIC and cat back..

 

Was hoping you guys in the UK with more VVti experience mite be able to shed some light on the situation??

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oLiD;1999701']chris, did the detonation stop once he went single ???

 

any ideas??

 

No idea, I had no further input after it was sold, sorry. Are you on the stock airbox and filter? If not, try to find and fit a stock set up, and let us know what happens. If you can get it to do it on a rolling road you could measure the timing off the front pulley and see if it's indeed having a fit. It'll take a lot of advance to det under no load, on a low CR engine. probably over 30 degrees.

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I am thinking its not actually det, possibly some kind of resonance frequency that is happening at that RPM, that just sounds like det, heat shield etc, i have had some very strange sounds from such items over the years, and sometimes its very hard to tell just what they are with all the other noise going on.

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I've has the same, same symptoms, same rpm etc etc.

 

http://www.mkivsupra.net/vbb/showthread.php?t=75461&highlight=PINKING

 

http://www.mkivsupra.net/vbb/showthread.php?t=107976&highlight=PINKING

 

Im bog standard TT VVTi Tiptronic, bar a cat back exhaust.

I've only ever used Tesco 99 / BP Ultimate / Shell Optimax and now V Power.

I still get it, every now and again, 2500 / 3000 rpm, no load.

I get it ONLY at this rpm range, gently accelerating, 2nd 3rd gear (Im auto) on slight inclines...when it happens, Im doing 20 to 40 mph say, in built up areas....NOT accelerating hard or building up speed, just pootling along. It goes away above 3000 revs, or if I accelerate.

Its rare, its random. Ive tried to emulate the noise on a steeper incline in top gear...the revs fall, the gear holds and pulls the car, no pinking.

New air filter / plugs / fuel filter / O2 sensor, made no change, coil packs are Im informed in good nick. SMIC next on the list.

 

I have had this, could find no cause, and no fault codes. A new AFM unit helped, but didn't entirely cure. I later found the blades on the front turbo compressor were damaged, but couldn't link the problems in my head. the car was then sold and went single turbo. car also had sporadic FBW throttle issues.

I should add that mine too had FBW throttle issues, eventually solved with a new throttle body complete with new sensors...the pinking still happens since, every now and again.

Edited by Ewen (see edit history)
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Guest [S]oLiD

thanks for the help guys, this seems to be a common issue with the VVTi's, there are a number of us here in OZ experiencing this problem and we cant figure it out....

 

when a car detonates, will the ecu cut the power ??

 

if its detonating because of too much heat, what would be causing this ??

 

i have a TRUST FMIC (600x300x115) and standard airbox, they should be doing the job..

Edited by [S]oLiD (see edit history)
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Guest [S]oLiD
I've has the same, same symptoms, same rpm etc etc.

 

http://www.mkivsupra.net/vbb/showthread.php?t=75461&highlight=PINKING

 

http://www.mkivsupra.net/vbb/showthread.php?t=107976&highlight=PINKING

 

Im bog standard TT VVTi Tiptronic, bar a cat back exhaust.

I've only ever used Tesco 99 / BP Ultimate / Shell Optimax and now V Power.

I still get it, every now and again, 2500 / 3000 rpm, no load.

I get it ONLY at this rpm range, gently accelerating, 2nd 3rd gear (Im auto) on slight inclines...when it happens, Im doing 20 to 40 mph say, in built up areas....NOT accelerating hard or building up speed, just pootling along. It goes away above 3000 revs, or if I accelerate.

Its rare, its random. Ive tried to emulate the noise on a steeper incline in top gear...the revs fall, the gear holds and pulls the car, no pinking.

New air filter / plugs / fuel filter / O2 sensor, made no change, coil packs are Im informed in good nick. SMIC next on the list.

 

 

I should add that mine too had FBW throttle issues, eventually solved with a new throttle body complete with new sensors...the pinking still happens since, every now and again.

 

Ewen, are you sure yours is detonating, did you have it properly checked and confirmed??

 

im hoping it isnt detonation but it sounds awfully like it..

 

i thought the ecu is meant to react to knocking, cut the power off or something?? mine doesnt...

 

i had my A/F ratios checked out and the car is running rich..

 

so confused ..... :(

Edited by [S]oLiD (see edit history)
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No, its not been confirmed as det. Its very difficult to get it to make this noise....when it happens, a slight prod of the accelerator will make it disappear, or changing gear too. I can only ever hear it with the passenger window open. It has not done it throughout the winter....I have been checking and listening for the noise since last July when I had a new plugs / filters / throttle body replaced, its only happened again since then recently, and then very very rarely.

Last year, Chris Wilson suggested fitting a boost gauge and recording boost levels at various rpms...I've not done that yet.

Chris suggested this due to a similar issue with another car that had damaged turbo blades...I've not had the turbos checked yet.

My SMIC looks a lot worse condition than it did last year, I'm in the process of organising a new one.

Edited by Ewen (see edit history)
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