I have detonation all of a sudden in my jap import tt jap import, im running optimax with jap plugs, it sound's quite bad! I seem to be getting it and a code 34, would changing the plugs to uk one's make a difference.

(standard boost)

 

what can I do my good friends??

 

need help!

 

 

Jim :cry:

SORRY! it is on uk plugs PRF711C should i put the jap ones backin PFR711?

what boost are you running?

standard boost mate?

You may have got a bad batch of fuel. Also, so you could try some octane booster. Also, double check the base setting of the ignition timing in case it's slipped.

I have detonation all of a sudden in my jap import tt jap import, im running optimax with jap plugs, it sound's quite bad! I seem to be getting it and a code 34, would changing the plugs to uk one's make a difference.

(standard boost)

 

what can I do my good friends??

 

need help!

 

 

Jim :cry:

 

Code 34 means there is something wrong with the detonation sensor or the circuit. It does not mean your car is detonating. Changing plugs fuel or anything else is not going to do anything. You are going to have to check the wiring and the sensor itself and depending on the results decide what action you are going to take.

i can hear the engine detting mate! and a code 34 comes up?

i can hear the engine detting mate! and a code 34 comes up?

 

OK the car is detonating but the code 34 is a different issue. When the ECU detects detonation it doesn't set any ECU codes. It will reduce timing temporarily until the next restart. If detonation is detected again it will put the car into safety boost mode which limits the boost to 7PSI and switches to the safety fuel and timing maps. If you have a code 34 then safety boost is activated straight away. Curing the cause of the detonation will not fix the code 34.

NGK plugs for stock TT are PFR6B11C Sounds like you may not have the right plugs in it

RIGHT, this could be a little in depth.

 

the plugs i had in where uk prf6b11c (sorry for the mistake), now today ive been in the garage and took the plugs out, had a look inside the cylinders and poked a long magnetic screwdriver in there, there seems to be what looks like copper grease on top of the pistons when scrapped? and very tiny metal filings came out on the end of the screwdriver(all cylinders), the plugs i took out looked as if they'd just been put in, very clean very white centre core. (no lightly coloured sandy dust).

 

ive just checked the tps, it's fine.

 

I conected my dodgey det sensor, and then went for a spin..........still the same i can hear what sounds to be a rattle on boost at about 40/50 mph

but no saftey boost even at 100 mph no saftey boost no (code 34) the needle on the boost gauge goes just past the last mark (not the end one)

 

it dose'nt ''rattle'' every time but it's been doing it for about a month now, I thought it was one of the turbos.

 

ive ran it on optimax for about 3 to 4 months now but used to run it on super unleaded and unleaded.

 

I don't really want to alter the timing as I don't have the timing tool.

 

does any one have any suggestions or what else I can try as im getting slightly woried about piston faliure.

 

many many thanks to all

 

 

 

JIM. :( :(

As Bilky says, standard plugs are PFR6B-11C. If you've got lots of mods then a colder NGK '7' or Denso '22' may help defend against detonation.

 

Take another loook at the plugs, they'll probably have tiny black blisters that look like specks of dust on them - this is evidence of detonation. Clean white plugs are evidence of running a bit hot - should be tan or light grey for correct running.

 

Check the ignition timing base setting, advanced ignition has to be number 1 cause of detonation. Mine slipped 15 degrees with no explaination and similar results to those you describe.

 

HTH!

 

RobH

how do i ajust it with no timing tool mate

 

 

cheers

You'll need to get a strobe timing gun to measure it safely. You'll also need a piece of old HT lead and spark plug connector to get a good reading from number 1 cylinder - the loop on the PTU is pretty poor for taking the signal.

 

If you're a gambler you could just mark up the CAS, slacken off the bolts and rotate the CAS clockwise a couple of mm at a time, checking for improvement every time you adjust (can't believe I've even written that - very bad idea!!).

 

My guess is that my CAS partially failed which caused the shift from 15 degrees to 30 degrees base setting (this is a reference setting that the PTU does its sums from - not the actual ignition timing advance setting).

 

HTH

You *can* use the loop on the PTU for the timing pickup too ;) Just don't let the clamp close over the wire ;) You can see the line jump as you open and shut the clamp :)

Alright Mr D?!

 

I still have your cam belt tensioners!!

 

People seem to report mixed results using the PTU loop - maybe it depends how good your timing light is...

 

Ciao!

you've lost me andy?

 

does everyone definatly think it's detting then from my long description above

 

 

cheers

 

jim

If you're lost then I wouldn't touch it tbh ;) There is the potential there to destroy your engine if you do it wrong! This is where an FAQ video section would be good :D

 

Rob - hiya m8! No probs I might be going to the meet in feb so maybe catch up then? ;) The trick with the loop will work with any inductive pickup timing light - like I say, just don't close the clamp over the wire ;)

 

CheerZ,

Andy

do you all think it could be the optimax? should I try an octane booster to see if it disapears first?

 

this is a stupid question I know, but it is'nt anything to do with putting mobil 15/50 in the engine is it (it's all started since that day i changed it) and it's alot darker and dirtier than at normal oil changes?

 

jim

I'd check you haven't knocked any vacuum hoses off around the plenum when you've been working on it - classic one is on the passenger side throttle body, just below the boost hose ;)

 

Oil vapour CAN cause detonation yes but you'd have to have pretty high quantities in the intake to lower the octane rating that far...

sorry about all the questions mate very helpful you are!

 

When i took the balance bar off to do the plugs i noticed pools of oil in the plenum?

 

jim

Yeah thats from the crankcase breathers. Have you done the PCV valves? Maybe they have jammed open...

year mate did them in summer, thanks.

 

jim

i put 15/50 mobile in mine and tbh its running sweeter than ever, mines a j spec and i rarely run on optimax/superunled as it hard to find with out goin miles away, i used standard unleaded and have had no problems, when i have tried optimax it didnt really feel diferent. so thats one thing out of the equation, sounds like somethigns been disconnected as andy says

just reading a few past threds, one says the VVT is controlled by oil pressure?

 

If my oil is to thick (15/50) could this readuce oil pressure enough for the VVT not to operate proprley, (ie timing) thus enducing detonation?

 

cheers

 

jim

Hows your cooling system? is the water topped up and clean? Running a bit hot can cause detonation.

just reading a few past threds, one says the VVT is controlled by oil pressure?

 

If my oil is to thick (15/50) could this readuce oil pressure enough for the VVT not to operate proprley, (ie timing) thus enducing detonation?

 

cheers

 

jim

 

No chance - different timings ;) VVT varies the valve opening time, the timing that causes detonation is the ignition timing...