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Gtr Making No Boost!

whiteboy01

By whiteboy01,
in Engines & Forced Induction

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whiteboy01 Collaborator

whiteboy01

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Ok guys here the story...

Driving along and notice a small leak from the rubber hose just past the twin turbo pipe. I didn't do anything for about a week :D . I no no... didnt' have any spare time so i diciced to drive underboost all the time. The car ran ok and make a very loud sucking sound.

Come to today (about 2 weeks later) I'm driving the car and not making any boost whats so ever and to my understanding it was that pipe being mega loose. So i got a mate to make me a metal pipe to replace the one that was alll busted up.

Replaced pipe and nothing. No boost and was running the same as before. Like the pipe was still off. WTF is going on?

Checked EVERY f**kING PIPE in my car atleast twice. Maybe more. It's not the pipes.

Checked the AFM and they are running ok.

The car is really sluggish to speed up when driving in any gear BUT is easy to start. No smoke on start up but heaps of black smoke with revs.

Thanks! :P

PS I hate this car when it breaks down :P but love it when it works :yes:

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Fry_33 Proficient

Fry_33

Posted
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A friend of mine started to have boost problems once and it turned out to be his CAT. The front part of the internal mesh had started to desintergrate and had sort of melted a bit so was block the majority of it, ie near zero flow.

Could it be the wastegate(s) are stuck open?

whiteboy01 Collaborator

whiteboy01

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A friend of mine started to have boost problems once and it turned out to be his CAT. The front part of the internal mesh had started to desintergrate and had sort of melted a bit so was block the majority of it, ie near zero flow.

Could it be the wastegate(s) are stuck open?

hmmm... makes sense. Because it was running rich all the time. O and a nother thing to add is when I rev it from idle the revs clime then drop off really quickly and nearly stall, then fix it self.

Wierd hey! :P

whiteboy01 Collaborator

whiteboy01

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The cat sound most logical cause of the amount of fuel vapuor been dumped the ceramic centre has proberly clogged up.

WOW i spent 4 hours trying to make something work and you guys come up with somehting i wouldn't even think possible! f**kING LEGENDS!

To late to try now i will do it tomorrow and report back!

whiteboy01 Collaborator

whiteboy01

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I had it happen to me so thats how i knew.

Cool. So if i just drop the cat and start it up i should notice it straight away? Doing this on a sunday so no places are open that sells cats. How do I clean the cat? Bash it out? Put a Pipe though it?

Risking Grand Master

Risking

Posted
Posted

cat is a remote possibility but being a GTR dave is going to be right in that its spat an exhaust wheel.

Blocked cat usually it will feel flat and retarded one blown turo will result in no boost what so ever and the symptoms you described

Bumblebee Experienced

Bumblebee

Posted
Posted (edited)

it wont be the cat. blown would make it feel like he just said, but theres 1 thing missing.. the black smoke. that means its runnin rich.. if the turbo was blown the afm wouldnt be reading more intake air and therefore adding more fuel... it'd read whatever was comin in. if the turbo wasnt makin boost, it wont put more fuel in.

I think u have a boost leak somewhere.. ive heard a few ppl sayin the bov's tend to leak boost on GTRs. im not sure how they work as i havent had a chance to look @ mine, but that might be a good place to start. Cats dont cause no boost, and if theyre "clogged" ud know about it.. the engine would sound like its tryin to blow massive amounts of air through a red rooster straw.. ud know about it hahah.

check the bovs out.

Edited by Bumblebee
whiteboy01 Collaborator

whiteboy01

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it wont be the cat. blown would make it feel like he just said, but theres 1 thing missing.. the black smoke. that means its runnin rich.. if the turbo was blown the afm wouldnt be reading more intake air and therefore adding more fuel... it'd read whatever was comin in. if the turbo wasnt makin boost, it wont put more fuel in.

I think u have a boost leak somewhere.. ive heard a few ppl sayin the bov's tend to leak boost on GTRs. im not sure how they work as i havent had a chance to look @ mine, but that might be a good place to start. Cats dont cause no boost, and if theyre "clogged" ud know about it.. the engine would sound like its tryin to blow massive amounts of air through a red rooster straw.. ud know about it hahah.

check the bovs out.

How do i check the BOV block one of the pipe off?

I dont' think its the turbos becasue it made boost just before the pipe blew. replace pipe and no boost? How can i root a turbo with a busted pipe?

whiteboy01 Collaborator

whiteboy01

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How do i check the BOV block one of the pipe off?

I dont' think its the turbos becasue it made boost just before the pipe blew. replace pipe and no boost? How can i root a turbo with a busted pipe?

O and another thing. I have a HSK after market boost gauge that goes into negative(?) before zero(?) then to 2.0 Bar if you no what i mean. The neadle sits in negative and when i give it some the guage goes to 0 and trys to go over but doesn't.

I hope that makes sense.

SLIPPERY Experienced

SLIPPERY

Posted
Posted

its a leak. The pipe may look like its on tight but there might not be a super tight seal. I suggest you re-do all the piping to make sure. It may take a while again for the little amounts of oil in the intake to seal the joins like before.

I had the exact same problem 2 weeks ago. Wouldnt make positive manifold pressure what so ever. I inspected the turbos and they were good. I re-did that damn bit of pipe straight after the merging of the two turbos with new hose clamps and the thing drove crappily. The next morning it was all good again

whiteboy01 Collaborator

whiteboy01

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its a leak. The pipe may look like its on tight but there might not be a super tight seal. I suggest you re-do all the piping to make sure. It may take a while again for the little amounts of oil in the intake to seal the joins like before.

I had the exact same problem 2 weeks ago. Wouldnt make positive manifold pressure what so ever. I inspected the turbos and they were good. I re-did that damn bit of pipe straight after the merging of the two turbos with new hose clamps and the thing drove crappily. The next morning it was all good again

but when you reved the car did it almost stall on the way down?

SLIPPERY Experienced

SLIPPERY

Posted
Posted

well, it got to the point where i couldnt drive up my driveway which is only a slight incline

The revs will drop because its overfuelling severely. To nurse it home i had to hold my foot on the accelerator. So to answer your question, yes :(

Fry_33 Proficient

Fry_33

Posted
Posted

I think it would have to be a leak of some sort.

If he had blown a ceramic turbine off he should have found bits of it in the cat shouldn't he?

As stated I'd be re-checking hose clamps are tight and check for cracked hoses etc. I'd be checking the vac hose that goes to the BOV as if that's not on as soon as you hit boost it will more than likely open as it won't have boost pressure from the hose to keep it closed.

You could block off the BOV by putting a thin metal plate underneath it to seal it off. Do this to just see if you can get onto boost, if so time for some new BOV's.

whiteboy01 Collaborator

whiteboy01

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I think it would have to be a leak of some sort.

If he had blown a ceramic turbine off he should have found bits of it in the cat shouldn't he?

As stated I'd be re-checking hose clamps are tight and check for cracked hoses etc. I'd be checking the vac hose that goes to the BOV as if that's not on as soon as you hit boost it will more than likely open as it won't have boost pressure from the hose to keep it closed.

You could block off the BOV by putting a thin metal plate underneath it to seal it off. Do this to just see if you can get onto boost, if so time for some new BOV's.

I had look in the cat and all that fell out was black water. The cat wasn't blocked. When I rev the car HEAPS of black smoke comes out of the dump pipes. Smells like fuel. Then the car nearly dies as it revs down. like it's flooded.

The pipes are all very good sealed. All of them are checked by me a friend twice each!

The BOV are next. Ran out of time today.

If it was the turbo broken would it still make it to 0psi and not move fromt the negative psi?

Could it be the ECU retarding something to stop me making boost?

Sorry for the blunt post i'm tierd as f**k.

Duncan Grand Master

Duncan

Posted
Posted

definately a leak somewhere. Air gets measured by the AFM, leaks out of the intake somewhere and the injectors still put in the full amount of fuel

can you hook it up to a smoke machine or maybe spray some start you bastard around and listen for raise revs

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