I have a Jap spec non turbo zx with an automatic box. Can any one tell me what the button 'power/hold' can do for me, and when and where I should use the overdrive. What is the most fuel economic way of using the gear box, and what is the most powerful.

 

cheers,

John

 

Power = Dont change gear till redline

Hold = Dont put as much power to the wheels 'type thing' (e.g. in the snow!)

 

Also, if you BOOT IT it will switch into power mode till your thirst for speed subsides (i.e. you stop hammering it).

 

Best way (for power) is to put it into Power mode but also use the gear shift. Keep overdrive off below 80MPH (ish) - keeps the turbos spinning .

 

For 'normal' driving leave it in normal mode (i.e. neither power nor hold). Its up to you how you play the O/D switch. Below 50/60 I tend to leave it off but then Ive got turbos that need spooling up - you wont have that problem.

 

/\/\ark

 

 

Surely, for the most economic petrol saving driving, leaving the box in HOLD with the overdrive ON would be the best bet? That would give the lowest revs with reduced power to the wheels. The only reason I bring this up, is that I managed to do 200 miles on a full £50 tank. How can I increase those miles - get more mpg. cheers.

 

Don't know much about this auto box business but here are a few general tips :

 

Try Cleaning the throttle bodies, the imports can have the odd nasty build up in there, then disconnect the battery for an hour and go and try again, see how much your GMP increases by.

 

Buy and AFC and lean out the mixture to the point where your Blow a hole thru a piston or two :o) not too recommended but you can probably lean it out a bit if you take it to a good tuner

 

Also try running super once, see what milage you get out of that. Yes it is more expensive but the japanese are used to 100 Octane, so is your engine.

 

Finally Z's and shite gas millage go hand in hand. Sorry bud. Shell Stock went down 3 points when my Turbo seized :o)

 

Z ya

 

Nico91TT

 

 

 

My mpg seemed to improve when I put my cone filter on. Can't remember exactly how much but it was noticable (the old filters were clean too).

 

 

I'm a bit of a novice when it comes to getting dirty with car engines, so I really not quite sure about all the jargon you guys talk about. Nico, maybe you could explain that last post to me as if I was a girlie. No offence if any of you here are girls btw :)

 

What are throttle bodies, where do I find them and what do I clean them out with?

 

What is an AFC and what is leaning out?

 

sorry about this, but I'm a good learner !! :)

 

OK here we go nice and girlie style:

 

Throttle bodies are these thingies here :

 

 

I know that yours will look a little different being a NA but i dont think there are any mjor worries, except the Pipe desitnations.

 

The following is best done about an hour after going for a good drive, hence the hardpipes are still nice and warm and maluable but the metal (beware the heat sink on the power trannsistor) is not too hot still as to burn thos delecate little hands.

 

Now take the Hardpipes that come off the Throttle bodies (large Metal Hole type things on big metal thing in middle of the engine bay, to put it scientifically) They are held on by a O ring Clip and you will ned simple a flat head screw driver to remove them.

 

Once you have them off you will see the Throttle Butterfly Valves behind them :

 

 

 

Simply open the Valves and clean off any black deposits you finish use carb cleaner or any other suitable solution use a appropriate cleaning medium also like a tootbrush and try to make sure no crap is left in there ( and dont use that toothbrush again afterwards )

 

Put the hard pipes back on,

 

Now disconnect the battery, and leave to simmer for an hour, Reconnect the battery and enjoy improved Throttle responce, smoother idle and better gas milage.

 

As for the AFC :

 

In woman speak the ECU determines how much fuel to issue depending on the mass of air passing thru the MAS (Mass Airflow Sensor), It will then dump said fuel into the cylinder via the fuel injectors. Now if you are clever you can trick the ECU into issueing less / more fuel by fiddeling with the signal it recieves from the MAS. Of course the unit does a bit more than just adjust the flow full stop have a look at :

 

http://www.apexi-usa.com/superafc2.htm

 

for details.

 

Im not sure how wise it would be to do this however, the AFC is premary use by Z owners to cut back the ammount of fuel that the JWT ECU issues at WOT on the TT Z's you can use it for anything you want if you have the right tuning equipment to tune it safely and avoid detonation. However i wouldn't just plug it in and start altering numbers and then caining down the M1 at WOT for half and hour.

 

Hope that sorts ya out a bit, Now i better have that Dam password and user name correct. or im coming for your SGI server with an Axe Craig LOL.

 

Z ya

 

Nico91TT

 

 

 

 

 

 

 

 

Nico,

 

Thanks for that girlie version - it's all clear now !! I hope you didn't take those pics just for my benefit. One question, why do I have to disconnect the battery for a time afterwards? Does the electricity flowing through that cause some kind of electrolysis to occur? And how often should I clean these out?

 

Oops, that's three questions :|

 

Thanks again,

 

John R

 

No Probs J.

 

Nah the pics were pilthered from Zhome.coms Hesitation diagnosis section.

 

If you had electricity flowing thru the throttle bodies you would now by the load exploding sound and bits if engine block flying left right and side ways on ignition.

hehe.

 

The actual reason that you need to disconnect the battery is to put the ECU back into learning mode. The ECU sets up some parameters for the Maps itself as no two engines and drivers are ever the same.

The thing is now you have more Air flowing thru the MAS than before as a result of cleaning the deposits out the bodies. So if you do not reset the battery chances are you will get a stumbling engine as the ECU is not issues the correct Air to Fuel Ratios into the cylinders.

 

You dont have to do it too regular, i clean them if :

a) im bored with nothing to do (i.e once per decade)

 

b) the missus is pissing me off ( 10 times a week)

 

c) i have the hardpipes off for some other reason ( 5 times a week LOL)

 

d) the cars is hesitating of has bad gas milage.

 

he he . I have the cleanest throttle bodies in the world then i guess.

 

Hope that helps.

 

Z ya

 

Nico91TT

 

 

 

200 miles on a full tank. That must be around town driving. If it isn't then your car has a problem with it's setup!

 

Andy