I have only had my Zed for a few days and it all seems to run lovely apart from a suspect wheel bearing.

 

I thought I should have a look at the buyers guide on this site (link below) and according to it I have compession problems:(

 

http://www.300zx.co.uk/tech/BuyingZ.htm

 

On the buying guide it mentions that if the needle on the boost guage is not on the far right of the guage on idle then I have problems with the compression. The needle on my guage is in about the same position as the bad guage in the buyers guide. Mine for some reason is only showing -7 and +7 psi whilst the one in the guide is showing 14. Is this because mine is an import?

 

Can anyone help?

 

Thanks,

 

Justin

As far as I am aware the needle should be near the far left of the gauge on idle not the right!!

 

The guage shows -7 and +7 because you have an import

Yes. The gauge is the same as mine -7 to +7 and is because it is an Import. As for your other question I can't help you.

As far as I am aware the needle should be near the far left of the gauge on idle not the right!!

 

The guage shows -7 and +7 because you have an import

 

Mine sits at about -6 on idle. Which I am told is correct.

As far as I am aware the needle should be near the far left of the gauge on idle not the right!!

 

The guage shows -7 and +7 because you have an import

 

Yeah, you are right, very sorry. I meant the left!

 

Thought that might be the resone for the different guage.

 

Cheers for the reply,

 

Justin

bare in mind that the boost/oil pressure gauges are not very accurate.

 

Vijay

bare in mind that the boost/oil pressure gauges are not very accurate.

 

Vijay

 

Yeah, good point Vijay,

 

I know if compression is bad then idle is supposed to be lumpy. No sign of that in my car. Infact if the compression is bad then I would love to know what my car would go like when it is right! :hyper:

 

I think I will get a compression test when it goes in for a service soon anyway for peace of mind.

 

Thanks,

 

Justin

Hi Justin

 

If your boost gauge needle sits more to the centre than left it could be something simple like a vacuum leak. Particularly in this recent cold weather, as the hoses contract reducing the seal effect (just like with fuel line leaks)

 

My boost needle sits just to the right of -14 (UK car) normally at idle, but during cold weather it stays nearer -7 (3/4s left) for the first 10 minutes until the engine is warm before returning to normal.

 

I had it checked by ZX specialist at local Mandella just after Xmas and he said everything was fine :cool:

 

HTH

 

Richard :smw:

Thanks Richard,

 

I checked this morning and the needle did get further left when heated up but still no further than I mentioned.

 

I will see how things go then for the moment and see if the problem goes away when the weather gets warmer.

 

Thanks for your reply,

 

Justin:)

Yep I was going to suggest a vaccum leak as well.

Vijay can still (as far as I know) get hold of a boost leak detector for about £20 odd quid. These are very useful to have as part of your Z tool kit.

 

A friend of mines Z was in about the same position and turns out he was running 5psi rather than 9psi due to boost leaks.

 

When you put your foot down does the needle go all the way to the right of the gauge ? (obviously don;t try it in this weather :D :D )

Yep I was going to suggest a vaccum leak as well.

Vijay can still (as far as I know) get hold of a boost leak detector for about £20 odd quid. These are very useful to have as part of your Z tool kit.

 

A friend of mines Z was in about the same position and turns out he was running 5psi rather than 9psi due to boost leaks.

 

When you put your foot down does the needle go all the way to the right of the gauge ? (obviously don;t try it in this weather :D :D )

 

Hi,

 

I am pretty sure that I do reach full boost.

 

The thing I don't understand is that it feels so fast, not like a car with any performance prohibiting problems. I took a mate who has a 350bhp Evo 6 for a spin in it yesterday and he could not believe the power.

 

Justin

If your zed has been in storage for months before you got it it can have slight gunging up on piston rings and valve seats etc. This will all clear after some days and weeks of driving and it'll get smoother and tighter on compression. So dont over react and dont roger it with too aggressive driving either especially when cold or we'll be hearing about your blown turbos next :)

If your zed has been in storage for months before you got it it can have slight gunging up on piston rings and valve seats etc. This will all clear after some days and weeks of driving and it'll get smoother and tighter on compression. So dont over react and dont roger it with too aggressive driving either especially when cold or we'll be hearing about your blown turbos next :)

 

Thanks Willie,

 

You might have hit the nail on the head there.

 

Due to shipping delays in Japan etc my car had been sitting for a long time.

 

Infact it was deregistered in Japan sometime in August and I only picked it up on the weekend. Looks like some Redex and plenty of Optimax should help it on its way.

 

Cheers,

 

Justin

The import gauge is in metric and calibrated in 100mmHg and the UK one in PSI.

700mmHg is approximately equal to 14psi.

justin, about a year ago my boost gauge needle kept going into the middle of the gauge when on idle, i found out on mine anyway that it was the boost gauge vacume line, its on the drivers side right at the back left, where they usually put the alarm sirens, its on a T-piece. On mine it had gone real hard and split, I cut it down a few times but it kept splitting.

 

after i got a new piece of rubber hose it has been fine since then.

 

hope this helps a little

 

Jim

justin, about a year ago my boost gauge needle kept going into the middle of the gauge when on idle, i found out on mine anyway that it was the boost gauge vacume line, its on the drivers side right at the back left, where they usually put the alarm sirens, its on a T-piece. On mine it had gone real hard and split, I cut it down a few times but it kept splitting.

 

after i got a new piece of rubber hose it has been fine since then.

 

hope this helps a little

 

Jim

 

Thanks Jim,

 

If the problem does not cure in the next couple of weeks then I will try replacing the hose.

 

Thanks again,

 

Justin:)