Hi. Ill try and explain the best i can as not very good with all this writing stuff..

anyways i bought a 1990 300zx tt the other day, with low milage and full service histort. It looked like it had been stood awhile tho

. When i went to pick it up it seemed like it was only running on a few cylinders.. This helped alot in knocking the price down severly.

Anyways i ended up getting it very cheaply.

we trailered the car away. Got it home and after a bit of research i decided to get some new plugs,fit them,also did the injector screwdriver test and found 2 of the injectors wernt working, i removed the plugs off them and found them to be green.

I cleaned the terminals up and refitted them. Started the car and great it ran sweet as.

After doing an oil,filter and coolant change i took it for a run.. Everything seemed fine until i tried to floor it.

Absolutely no boost. Car runs sweet, the stock boost guage goes up to the 0 then stops. When i slow down the guage goes back into -..

Cant even hear if there spooling or not..

Al i do know is there is no hissing or strange noises from the engine bay. Ive had it on the ramps today to check as much as i can and all seems fine no apparent split hoses, turbo's and actuators all seem fine and are where there sposed to be..

Totally at a loss now and time to ask for some advice

I know my way around jap stuff and have owned a wide variety of old school jap car but have nevet come across this before..

Last time i had a similar issue was wirh my r32 skyline but even tho it had a boost leak u could still hear the whoosh as the turbos spooled but obviously didnt get much boost but it still ahowed on the guage as boosting..

This car doesnt even get past 0 pn the guage lol

Now ive checked with the service history and everything adds u with the milage and its the original engine according to the numbers.

What i did find tho was a receipt for a superchip, performance exhaust,top end overhaul to the heads and a refurbishd and uprated gearbox to apparently handle the extra hp. Thr dyno receipt shows 376 bhp??

This to me sounds odd as i think it would ov needed more extras on it to make that kind of hp gains!!!

I havnt fine through all the service hostory yet as there is so much..

Also ive noticed there was an ebc fitted but it has been removed

Any help and advice would be greatly appreciated

Maybe your turbos are knackered... Engine out to change them :whistling:

 

You can remove the hoses and put latex gloves over them... And see if they inflate, that's one way to check although dont ask me to go into any more detail that's all I know lol :)

I think these days that's a fairly easy figure to hit mate (I'm guessing flywheel?).

 

You could have a nasty boost leak maybe?

Maybe knackered knock sensor? Might be a daft question with you being new but do you have conzult or any other diagnostic program? Might be worth getting it in a local members if not

Edited July 20, 201312 yr by bird

I'm in peterbough a couple of times a week. I don't mind giving it a plug in for you to see if it throws up a code or two.

Could be in safety mode, need to get it on consult or datascan, i would take up the offer of a plug in from cyberbean, could save you lots of searching and headaches.

Given the engine runs well as you describe there is little chance you have a boost leak large enough to have no boost at all.

 

Almost certainly you have a seized turbo, and in 99% of the time it will be the passenger side turbo that fails in this way, any boost produced by the other turbo short circuits and is lost past the stalled turbo and down the exhaust.

 

You can change the passenger side turbo with the engine in place quite easily so no engine removal required, check the failed turbo by removing the big throttle pipe and run the engine, feel for boost at the steel outlet coming from the intercooler ( not the throttle )been produced when revving the engine, try both sides and it will I am sure prove the n/s turbo is seized.

 

Jeff TT

Edited July 21, 201312 yr by JeffTT

thanks.. ill check to see if theres any air moving from them pipes tomorow and yes id be up for any assistance cyberdean..

i got 2 garretts from my m8 sat in my garage.if it proves to be the turbo/turbos ill get them changed..i do like a challenge lmao.

yes ive heard of this safety mode from the research ive done,and i havnt checked for any fault codes as im still struggling with the destructions on how to do it lol

so will there be much air coming from these pipes?? enough to just feel??

if no air felt leaving the pipe then knackered turbo??

as i understand it,boost safety mode cuts the boost solenoid but the turbo will still boost 6-7 psi on the wastegate??

if thats correct then mine cant be in boost safety as i cant even get any boost.lol

Safety boost as you say just lowers the boost not removes all boost, the easiest way to feel for the boost at the steel pipe is to place a rubber or latex glove over the pipe and it will either slowly inflate if the turbo is ok or will suck in slowly if the turbo.

 

Jeff TT

You can always rely on jeffs sound advice. That said any luck yet jeff?

Well did the layex glove idea and both worth not blowing.. Seemed like they were both sucking the glove in..

Guess i know what ill be doing over the next couple of weeks:( lol

Is it safe to drive the car around obviously slowly??

Will it do any harm??.. Ive driven it around town over last few days collecting parts for it. Like i said apart from no boost atall its running fine!!

Bit of an update...

Decided replace the turbos but as we removed the plenum we fount almost every hose was split and the accordian hose to the passenger intercooler wasnt connected.

The plenum has excessive oil laying in it inc all the pipes to the intercoolers

Could this all result in complete loss of boost??

 

Ive aquired a plenum with an egr delete kit alredy fitted , a couple of arc intercoolers and airbox of my m8 whos helping me fix the car so theyll be fitted as soon as the replacement hoses arrive:)

If your going that far detach the front hard pipe on the turbo face and GENTLY try to turn the turbo by hand. It should spin smooth as silk. Lots of boost leak are not going to help though and I suggest you replace as much of the vac hoses and water hoses as possible while you there as well as deleting the dross. Plenum water pipes aiv etc.

You've done a lot quickly... Nice job

Thanks checking the blades will be a tomoro job.

Ordering all the hoses tomorow morning and also removing the plenum water system.. Luckily i got a freind helping who has already done all this to his cars so all looking well.

Ive worked on quite a variety of jap engines over the years and to date i still have nightmares were the gto-tt's are concerned.. Lol

So far the 300zx-tt is challenging but not impossible:)

been at it today and:

removed stock airfilter box, pipes and plastics to make was for the ARC airbox

removed radiator, coolent pipes and the 2 silver pipes from the block and found my water leak

removed recircs,full of oil and replaced with dv29 baileys

removed both accordian hoses left side had a hold and the right side that wasnt even connected to the ic was split at the turbo end

removed intercoolers.pas side was fine but drivers side had lots of oil in it and replaced with a pair of ARC intercoolers

checked engine oil level and was a long way past the full mark which is making me think this is were the oil has come from,drain and refill with new filter

checked trans oil and that is half way up the dipstick so thats gona get drained out and refilled to the proper level

stripped old loom of to make way for its replacement

found the knock sensor loom was not looking healthy so replaced knock sensor and loom

found the driverside o2 sensor wasnt even connected due to broken plug,replaced plug

did the water bypass mod from under the plenum

also removed old egr system and fitted the egr delete kit

 

new pcv hose kit and all the other hoses that we dont have spare ordered and should be here tomorrow inc the plenum gasket

new platinums fitted

pik of pass accordian hose turbo end

checked ecu to make sure it was modified to back up the history.opened it and yes its chipped:) and on the lid we found

looking forward to tommorow when we can start re-assembling and hopefully should have it back on the road by the weekend:)

Looks like you are steaming through. Once it is all back together i'll come buy and plug her in to make sure all is fine.

Looks like you are steaming through. Once it is all back together i'll come buy and plug her in to make sure all is fine.

 

Thanks bud that would be awesome...

Well.. Got it all back together and its runs soo sweet BUT. still no boost.. After all the things we fount wrong we thought it would ov been sorted but hey...

Will pull it all to bits tomorrow and start again, i know its gona be a horrid job to replace the turbos, but itll be worth it in the end..

Bit miffed today so going for a long soak in the bath and chill till tomorrow

You can remove the fronts of both tubbies and check them for play and wear before going to far.

 

Its pretty obvious it has to have dead turbo or turbo's so mite as well go all the way:)

Bit of an update.. Removed passenger turbo and its fine.

No damage, splindle and blades all fine and spins freely so its not that turbo..

Was expecting to find something wrong with it:)

Now im baffled, will start on drivers side turbo today and hope that one is fine!!

Dont make sense... If passenger turbo is fine then why wont it boost?? Surly it has to boost if theres nothing wrong???

ozzizere, would you mind dropping me an E-mail in regards to steering wheel please: - Cheers.

Edited July 26, 201312 yr by 300ZX_666
Removed email address

ozzizere, would you mind dropping me an E-mail in regards to steering wheel please: - Cheers.

 

Email sent:)

Edited July 26, 201312 yr by 300ZX_666
Removed email address

Driverside turbo was seized solid..

Both turbos now replaced..

Just got to get a broken stud removed from the drivers side turbo elbow then the car should be back on the road:)

Looking forward to finally driving this thing as it should be ( turbo not n/a ) lmao