Fellow Zster,

 

I just started noticing that between 2 and 3k RPM my engine is making the nuts-and-bolts-in-a-baked-bean-can noise. This is while I'm cruising at motorway speeds and although difficult to hear is a sustained rattle which gets slightly louder when accellerating. Is this detonation or what? Also, I seem to have lost a bit of top-end boost. Whereas I normally get the boots needle up to the second to last minor line (my gauge is stock Jap which runs from -7 to +7) now it stops at the only fat line between 0 and +7. Does this indicate that I'm in safety boost mode? Can this be caused by the detonation problem? I get this every time the engine has warmed up so resetting the ECU won't help. While in Holland, Eric performed an ECU test that indicated 34 - Det'n sensor. Reading all of your previous posts on this subject I understand that indicates my det'n sensor is shot or the wires between the ECU and the det'n sensor are gone. Also understand that it's not worth the money to replace the sensor (as the engine needs to be taken out) and can be by-passed - how?

My question is what do I need to get checked? Timing, mixture, spark plugs .... Is there anything else that can cause detonation? What is the base timing for a '90 ZX TwinTurbo automatic (Jap import and completely stock as far as I can tell)? I guess I need to take it to the dealer to have it checked - unless someone around the Birmingham area can do this for me ...

 

For future reference, if I want to replace my spark plugs, which make and model do I get? I am not intending to upgrade the power of the car in the near future, with the exception of perhaps a K&N cone filter and a B&B exhaust (Eric - yours is absolutely the dogs dangly bits!!!) I have read the previous threads on this issue but am still confused - I need one answer, not a range. My take on the situation is iridium plugs (hot, i.e., rating 5)? Am I even close?

 

Many thanks guys!

 

Z ya later!

 

Dan

Sorry to have been rambling on --- I'm having a crap day at the office .... ... and this seemed like a much better use of my time

 

Dan

Bloody hell Dan mate, you really are going through the mill at the moment aren't yer?

 

Det sensor can be replaced with the engine in I think, more labour cost than anything just stripping the whole thing down to get to it.

 

You can bypass the sensor, I thought it was Mr. Lymon that did the procedure??? Or was it Maciej(Z Viking where are yer?) but this is not recommended! More a quick fix which then leaves your engine exposed to full on destruction.

 

NO, it was Mr. Le Hir if my memory serves me correctly...procedure is either on Zhome.com or TT.net.

 

Jeff is round Brum way along with Matt Lad...thought you were gonna meet up with them? You'll just get jibberish outta me chum Mattley as me and him share Z f**kwitness in common I'm afraid. We are more Zurf bums than guru Zwami-Z's...LMAO! But try Jeff, he's a very knowledgable chap!

 

Plugs mate? I would go with Iridium, but don't hold me to that, that really is my personal choice and will be whacking a set in when I get her back.

 

Have a look at www.hiteq.co.uk, they are based in Wigan and I think that they do the HKS Iridium plugs for our carZ!

 

What was the other thing you wanted to know? How much are value Baked Beans at Tesco? 19p mate!

 

Later Dan the man...

 

Tim the bin...

Very funny Tim ! Perhaps if we start a separate thread on a group buy of these Tesco goodies, we can get a discount and cheap p&p ....

 

Later!

 

Dan

 

PS - Yes, I've been through the mill, over and around it and now I'm fed up with with looking at it ... I did arange to meet up with Jeff and Matt the lad, but as luck would have it my Zed gave up the day before the meet ... Should get it together soon though!

 

[This message has been edited by Danny (edited 08-08-2001).]

Hello Danny,

 

I had the same problem about 2-3 weeks ago and shit myself. Aparantly the wiring harness does tend to suffer with the extreme heat, but mine just turned out to be a dodgy connector, I cleaned it up and hey presto. I believe code 34 will put your car into safety boost and retard the timing. If you want to get round the sensor, here's the link: http://www.zhome.com/ZCMnL/PICS/detonationSensor/detonationSensor.html

 

p.s helpful people on here arn't they!

Vijay,

 

Nice to hear from you m8ty - sounds like you're having a whole load of other problems from the usual ... It's hard keeping your eyes on the road when you're playing with gadgets, ain't it?

 

Anyway, thanks for the link - gonna look at it over the weekend.

 

Cheers for now!

 

Dan

Morning all!

 

Is it possible for detonation to "come and go"? Yesterday evening as I was cruising up the M40 to Birmingham it was quite loud whereas this morning (going down the same stupid M40) it was barely audible. What gives??? I haven't touched anything in the engine. Also, if the ECU has put itself in safety boost mode, can it take itself out of it while the car is being driven? Just seems that my boost was better about half way into my journey this morning ... Zeds are just like women - I'll never understand them but sure as hell wouldn't want to be without them ... muhahahahah!

 

Cheers!

 

Dan

 

The only way to reset the detination caused safety boost is to turn the ignition off/on, which get the ecu to clear it.

 

Detination can come and go depending on loads of factors, the main one being heat. So it it's hot outside or the car is hot it's more likely.

 

Are you sure your engine temprature sensor is performing correctly, perhaps your car thinks it's still warming up or something. The one that goes to the ecu, not the one connected to the temp gauge!

 

If you are getting detination all the time I would not drive the car, you may damage it. Occasionally when under load, is not so bad.

 

If your detination sesnor is bad, there is a tech on twinturbo.net to get around it, if you really want to do that. Although it could just be the connectors, there is one big plastic one right at the back/top of the engine bay - for instance.... check it.

 

Have you checked your timing - for about 15deg... it's important not to be over if you want to avoid detination.

 

Good luck...

Finding someone with a Techtom (me, Timmy Turbo, SteveE) might help. Or a Consult, but that is most likely to be a Nissan dealer.

Danny, I would replace that plug on your temp. sensor first.

It was completely knackered and it might well be the cause of the detonation.

Also check your O2 sensors ( http://www.ttzd.com/tech/diagnostictech.html )

 

by the way...here's a clear picture of that damn det. sensor on a stripped engine.

You can clearly see it'll be a major bitch to get to it.

 

-Eric

 

[This message has been edited by lymon (edited 09-08-2001).]

Eric m8ty!

 

Good to hear from you! I'm still not missing the blasted speed chime you so kindly disconnected for me, LOL

 

Tell me, would a leak in the air intake hoses cause detonation? A guy I ran into yesterday (works for RipSpeed) suggested that on turbo engines even a minute leak in one of the hoses could cause detonation due to too much air reaching the turbos. Is he talking bullshit or is there truth to this story?

 

Looking forward to seeing you in September!

 

Cheers!

 

Dan

 

what he means is too much (unmapped) air reaching the engine, thereby making it run lean, and making it detonate...

 

 

nah...a small vacuum-leak won't do much harm on stock boost.

Only on a very hot day and in combination with bad fuel maybe.

 

A big leak is something else though..but then the car will idle like shit and

you will notice it on the boost-gauge (during idle the gauge will show around -7psi or worse, closer to 0)

 

-Eric

 

PS: did you find that damn "reverse"-chime yet ?

 

 

[This message has been edited by lymon (edited 09-08-2001).]

that dotn make sense, if oyu have an air leak you are getting less air in the intake (am i mistaken, considering im not even here) that he got that mixed up?

 

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

depends on where the leak is..

if it's before the turbos, it will allow more air to be "sucked" into the system then the AFM will measure and therefore the mixture will be too lean.

If it's after the turbo's then usually what happens during boost is that a small amount of air is blown away out of the leak and out of the system and therefore the mixture will be too rich.

(Comparable to what happens if you have BOV's)

 

 

[This message has been edited by lymon (edited 09-08-2001).]