Hey guys,

 

I have tried everything I can think of to cure my detonation problem and nothing has helped. So far I've tried running on Optimax exclusively (well over 2000 miles by now), changed to a JWT chip, changed to NGKxx-11b spark plugs from Courtesy, cleaned every sensor/connector I could get my hands on, even installed a JWT pop-charger and corrected the timing to 15degrees BTDC. Still the same rattling noise between 2k and 3k revs under light load.

Under Jeff's thread Phil_m mentioned clogged up injectors and the lambda sensor. How do you clean the injectors and how do you check that the lambda sensor is functioning properly?

If there is anyone else out there who could run off a list of possible causes of detonation then please clue me in ... I'm getting desparate now.

 

Thanks for you help guys!

 

Danny

 

[This message has been edited by Danny (edited 17-12-2001).]

hi all.. been busy lately haven't had a chance to log on at all really.

 

Righty ho.

 

Possibility 1:

Have you taken your car for a decent drive lately, I mean a decent balls out give it death drive ? Why do I ask.. carbon buildup. It's not entirely impossible that your car has a build up of carbon in the cylinder heads.

 

Possibility 2:

Also if your fuel is anything like ours the JWT chip will not actually help the ignition curve, NOR will the stock Jap chip. Note that the problem is NOT a/f ratios but actually the ignition advance curve for the fuel spec.

 

My Z with the stock Jap chip pinked all the time on light acceleration in the 2-3k range, then timing is advanced and the pinking dissappears. If you've got a really good "ass-o-meter" you can actually feel the ignition change.. I never knew what it was until I plugged in a techtom and watched the ignition jump from 30 to 10degress, you can just feel the engine go flat for a breif split second before boost comes on.

 

I've seen a JWT chip remapped for our fuel that had the ingition timing pulled back a little so it went flat earlier and thus stopped the detonation.

 

One of my mates who's quite into these cars has seen quite a few Z's do exactly the same thing, at 2-3k pink and then dissappear. My car has done it for 4 years and I haven't popped anything !!! It's not harmful as the engine isn't under enough load to do damage.

 

I've done exactly the same as you, junked the stock jap chip, put in PFR6B-11B plugs (didn't make squat difference), went to high octane petrol (this alleviated the problem but didn't eliminate it completely), Stillen intercoolers. The only time I can make the engine do it now is say 80kph floor it in 5th gear going up a hill, as that is when the engine is under the most load, the ignition timing isn't pulled out and ping ping ping...

 

Unless it really is rattling it's head off then I wouldn't be worried to much.

 

The *ONLY* way I have dealt to it completely is to run racegas. The engine becomes a helluva lot more responsive and the pinking dissappears completely.

 

Remember in Japanland they have 100 Octane fuel (bastages)

 

Rowan

Hi guys!

 

WOW !!! I'm absolutely overwhelmed by all the responses I've had so far to this thread. Thank you to you all.

 

Looks like I have an awful lot of things to check and as soon as I get an afternoon off I will try and get as much sorted as I can and report back to the forum.

 

AndyP - if it still isn't sorted in the very near future I'd appreciate it if I could take you up on your offer for a go with the Techtom. Will let you know when I'm next in your neck of the woods.

 

Thanks again guys - this really is the greatest forum on the web and you're all top bananas!

 

Cheers

 

Danny

With all this techy stuff this may seem stoopid...but anyhow. My car has only ever pinked once on me at 40 - 60 mph at slight acceleration and i mean slight and then it would go away. It didnt do it before so it had me worried, no errors in the diag. Turned out to be a loose fuel hose just weeping, tightened them all up and it went immidiately.

 

Worth a try and is free.

As Rowan said shove a shit load of Octane Booster in Dan the man. Remember, Optimax isn't quite 100 octane and I would get the heat shields checked aswell. My car developed a few rattles which I've now put down to the ATF tube not being attached correctly or even at all to the bell housing!

An easy way to check if it is detonation is to retard the timing a little and see if it stops the noises. Make sure you mark where the CAS was before you do this.

 

Further to Rowan's comments. Thats why I will never purchase a pre-mapped chip that is not configurable. Not all cars are equal - they have their own characteristics. I much prefer to purchase a configurable chip and have the timing mapped manually throughout the rev range. This ensures you get the best power curve available for YOUR engine.

 

Andy

I agree entirely with that last statement

 

RR day obviously showed that if you bolt on zorst, intake and upgrade ECU etc. you may not necessarily be producing efficient or safe horses!

 

Which is why I'm gonna run mine on a dyno before I do anything else, then add the other bits and pieces that I've got waiting to go and and then get in touch with Pete. Then I'm off to Essex for the day hopefully to get the car setup better! Has to be a wise move

Would you also all agree that is you want a custom mapped chip for peak HP that is dyno Tuned for your car running the exact way it is tuned, At the Dyno Tuners Establishment , at that temprature on that day - you are gettin exactly what you ask for . . . .

 

 

 

------------------

Z ya

 

Nico91TT

 

Oh Nick you can be such a one sometimes can't yer???

 

Nah, I meant similar to how Iain and Hairy's Z's were setup. I read an article on the Aus300 site a while back that AndyP put up on here.

 

Some guy took his 300 to a dyno to find that it was running lean I think and not putting out anywhere near what it was capable of. So they did a few runs and arsed with the mixture a tad and not only made his car run safer but also released a few extra horses in the process

 

Isn't that what these people who run Dynos are all about after all? Most of them are used 24 x 7 to tune rally cars etc.

 

I know that you could be putting out 400bhp say one day and two days later on the same dyno because it's 3degrees colder outside run 410bhp. Not that cynical(is that how you spell it?) just want to know that once I've finished with Blitz zorst, intake and running SE chip that the car is running approx. as it should. Safely!

 

Like the guy on the Soup forum recently who blew his engine up! Was chatting to Johnny about this, some of the boost controllers you can buy claim to set the boost limit at whatever you set. Not all of them cut the boost pressure at the limit you set, so continuous overboosting and BANG!!! I hear that Soup engines are rather expensive to replace aswell

 

See?

Timmy timmy timmy,

 

Yeah i wasn't Dissin the Custom Chip market in Anyway - If you want Peak HP then that is the ONLY way to go - Off the Shelf chips can't possibly compete. . . That is why all Race spec cars that are competive are tuned for each run !

 

I was making the point 'Be Carefull what you wish for you just might get it ! '

 

Anders ,possibly without knowing it, brought up both a argument and counter argument for the Custom tuned chip.

 

The reason all cars are different at a mechanical level is due to just that if you get my drift - parameters change, injectors stick, Heat increases, Pressure changes - Even outside influences as i mentioned. IF you do buy a custom chip make sure that you get it tuned to a safe level

 

Peoples interpritations of the word safe vary greatly between tuners.

 

JWT chips are outperformed on the Dyno ! Why because the Dump a shit loads fuel at WOT why is that ? - You tell me - Good tuning nope ! then what ?

 

I know i have a JWT for just that reason - I also have EGTS for the same reason - coz i dont trust my chip as much as the next guy to keep my 7.5 grand engine safe at 17+ Psi.

 

Sorry if in going on a bit here - I've got absolutly no problem with the route that timmy has chossen for his car - I just want to try and get the message out there - i know that most advocates of the JWT have stopped posting on here, coz when they do they get slammed - all i wanna say is - If your gonna get a custom tuned chip then - please make sure you know what you are asking for - and you get it !

 

Ive heard to many people crying over a blown piston

 

14psi of Boost + incorrect fuel map WILL kill your engine !

 

Also if you are thinking going off the shelf make sure you get one that is tuned for UK fuel - JWT do obviously do such a chip - MINES are generally tuned for 100OCT japan Fuel but i think you can have them remapped at Xtra expense.

 

Superchip 'allegadly' Complete garbage ! may as well stick Microsofts Barney on the end of your loom and ask him for Max Boost

 

 

 

------------------

Z ya

 

Nico91TT

 

a good dyno tuner will have the knowledge and experience to make a chip suited to your needs. our local boy is quite good and it, and will even make you chips for different applications, like one of my mates runs a "round town/safe race track" chip for pump gas that puts down about 230rwkw, however then he's got the "racegas good luck" chip which dumps 249rwkw, this has a retarded ignition curve, remapped fuelling (race gas likes slightly different a/f ratios)

 

If you've got a muppet who tunes for maximum performance on one dyno run you're asking for trouble

 

EVEN on the programmable ECU's I've seen one tuned in winter, car changed owners, new owner was warned to get it retuned for summer, ignored advice, heard it detonate (high revs/boost detonatoin the bad kind), 3 weeks later popped #6....