R34 Gt-t Power Cuts Off *help*

[maddowse]

hi guys i had a look at his car today (im not a mechanic but any bit of help is good) firstly this thing boost's way too hard for a stock setup but i couldnt find and obvious leaks and the actuator is normal (couldnt see if shaft had been shortend though )and there is no boost adjuster fitted , but he has a tone of oil in the inlet pipe from the afm to the turbo so i think the high boost has caused a seal to go on the turbo . but in my opinion its def a coil pack failure it feels like TSC cut but it does it under boost with the TCS off . i sugested he go get a power run on a dyno with trent because from what i understand the dyno will pick up a coil fail! is this right ??

also we tested my AMF on his car with no change to symptons so its not the AFM , car idles fine just cuts out when you push the revs

iv never felt detination from having boost too high but this could be another cause but i wouldnt know what to look for i still think its coils .

so if anyone can give him a better idea from whats going on with the decription i can give ?

[maddowse]

just a thort mate ur turbo might not be stuffed because of the high boost ! the high boost is becacause of the oil leak in the turbo . check your boost solinoid and all those boost lines leading to ot i recon there full of oil , so you car is over boosting , once you fix your car will be slower but at least it wont blow your motor . also get your coils fixed

[maddowse]

can anyone advise him ov the name and number of a turbo specialist in the cheltnham area ?? i think he needs to get the seals in the turbo fixed first then clean out the boost/vacume lines and soliniod, them fix the coils and do sparks at the same time and it should fix his problems

[Galois]

If you disconnect the factory boost controller you'll be able to determine the boost pressure the car goes to based only on the actuator.

Maddowse, did you ever find the source of your high boost? I commented my solution in your thread ages ago, it's either a tiny leak that I couldn't find in the line from the factory boost controller, or the controller has been modified.

[Charlie Bun]

Woooo... thanks heaps Maddowse, today you have been a really helpful and that you have released huge stress out from my head.

Erm now i am also positive that it is the coil packs problem, and sadly there is an issue on top which is the weird dirt oil in my turbo and through those pipes. (Does anyone else has this this problem?)

btw love your car bro...

Charlie

[Galois]

Coilpacks do have a used by date for skylines, but you could try changing the plugs, go either ngk bcp6res-11's, bcp6res, bkr6es-11, bkr6es or bosch plat fr7dp's or fr7dpx (-11 means 1.1mm gapped, no "-11" means 0.8mm, and the x means 1.1 gapped, no "x" is 0.8 gapped). The ngk's can be had for round $30, the bosch plats are about $40, they both last similarly as long though (round 5000km).

Don't bother spending much money on iridiums or plats (ngk plat's are like $17 each), some people find they last a few tens of thousand kms, but the vast majority don't.

[Wacky Dee]

stop the guesswork, just take it to an import mechanic .. plenty of them in Melbourne, just ask in the Vic section.

[maddowse]

Hey galios yeah the high boost on my car was from having a different actuator ! All sorted now thanks for the help on that .

[mad082]

have you put an aftermarket boost gauge on yet to see what boost pressure you are actually running? doing this could immediately tell you if the problem is boost related or not.

would also be worth checking the timing. if it is too advanced then the ecu may be backing off the timing and adding in more fuel, making any missfire caused be weak coils/plugs worse.

[maddowse]

have you put an aftermarket boost gauge on yet to see what boost pressure you are actually running? doing this could immediately tell you if the problem is boost related or not.

would also be worth checking the timing. if it is too advanced then the ecu may be backing off the timing and adding in more fuel, making any missfire caused be weak coils/plugs worse.

my boost is set to 11.5 (by trent at status ) and his car is boosting way harder than my car !,

as i said above his intake pipe is caked with thick glugy oil so i think the vac lines are blocked restricting air to the actuator so its over boosting ,

as for the power cut ic could be spark plugs are loged with oil but i still think coil packs will be the problem

i think he best step is to go to a tuner or a good mechanic (not the one he has been taking it to ! didnt spot a buggered turbo!!!)

and go from there

[mad082]

if it is over boosting then the ECU will cut the power. that is why before he spends any money on getting it professionally looked at (and spending money in the process), he could simply put a boost gauge on it and see what it's running at. if it's 13 or 14psi then that will be the problem and simply cleaning out the vaccum lines and actuator and making sure that the wastegate flap is able to open properly and isn't fouling on the dump pipe would be the things to do.

[maddowse]

good point

[Charlie Bun]

Ohh ok thanks guys. Ill check with some professional prob Thursday or something. But in the mean time can i still drive the car? Do you think i could blow up the turbo or engine if i keep on boosting?

If i drive normally would it still be bad idea?

[maddowse]

i dont recomend it as its probably boosting at actuator perssure and will cause further turbo problems (better to fix a blown seal than seezied turbo )

its a pitty i know as you have finaly gotten your self a turbo and after two weeks told its not a good idea to drive it ! but best be on the safe side

[mad082]

if you don't floor it it should be fine, basically don't let it boost fully, drive it like a nanna and you should be fine.

[Charlie Bun]

I ses.. I see....

Ill try to get it fix ASAP but I keep it low when driving it.

I will post the result after fixing it.

[Charlie Bun]

Hey guys, the other day i brought my car to this place called R.E in Westall.

Anyways RE was too busy with the other cars on this dyno which he couldnt come out to have a conversation with me. However, another guy came up to me and asked what was my problem. I told him about it and he said he had the problem before and it was this boost sensor at the back on the engine and its attached to firewall of the car. (You guys might confuse which one im talking about but this one is easy to take off or disconnect). So we disconnected the plug and the problem was gone, however the high boost was still there. Right now i am driving it with the boost sensor unplugged.

So the questions are:

1. Is it because of my boost sensor playing up which is why i have a boost cut after about 5000-5500 rpm?

2. If I keep driving with the boost sensor unplugged, would there be any consequences? e.g blowing up my engine, turbo or gasket etc?

3. WIth the high boost - should i just buy another turbo and replace it for get someone to rebuild it for me?

Thanks guys

[paulR32gtr]

1. No - the turbo is overboosting, the boost sensor (MAP sensor) is just telling the ECU what it is seeing, and the ECU is cutting the engine out. By disconnecting the boost sensor you are just tricking the ECU so it can't see how much boost the turbo is producing. The overboost is the problem - not the sensors / ECU.

2. Yes - only drive like an old lady until you have it fixed - your turbo is boosting way above what it is meant to, you risk leaning out your engine and blowing it and / or blowing your turbo from overspeed

3. Depends what is causing the problem. You should be able to get the wastegate working correctly again - based on what people above have suggested (ensure lines to wastegate actuator are not split / leaking, ensure wastegate on turbine housing is not hitting dump pipe etc).

If you have heaps of oil in the intake pipe this could either be from a leak on the compressor side of the turbo, or it could be carbon build up from blow by / crankcase breather. You will be able to see a leaking compressor easily by taking the pipe off the compressor intake - the wheel will literally be sitting in oil. You would also be getting heaps of blue smoke out the exhaust.

[maddowse]

first this as i said on the phone ! replace all you vac/boost lines as i think there blocked with oil also clean out your boost controller with wd40 .

secondly if the turbo is stuffed (i recon it is with all the fresh oil in the inlet pipe) here is a turbo for sale in frankston at a good price $400

http://www.skylinesaustralia.com/forums/R3...ts-t344501.html