R33 Gtst No boost.

[KLA33E]

R33 Gtst No boost.

Hello!

Just got my R33 passed inspection this week and finally got her out on the road!

Today I was washing the car, on my way home I went full throttle for a short moment and backed off at 5200rpm, then the car literally had no boost after this pull, maybe like 2psi at max. I stopped for a brief period with the car still running, then I drove off and it boosted like normal again!?

I got home left some things and went for a drive again.

I eventually came to a straightaway and wanted to see how the car would behave so I hit full throttle and it boosted fine, I let off at aprox 6500rpm. Then SAME THING AGAIN! no boost and this time it didn't come back. So I drove home with no boost.

The car is fairly stock, it got a bigger exhaust, pod, Fmic, Splitfires coils, and Electronic EBC (Greddy profec B II). I was driving with the Boost controller of. It usually boost between 7-9psi, so not alot. 

The wierd thing is that the car idles fine, sits at 800rpm and sounds normal. If it were to be a big boost leak the car would run like crap and very rich, right?

my Wideband Readings showed 11.2-10.9 at WOT Before this occured. 

You Aussies seem to have good knowledge in these cars. Have any clue what this might be?

Cheers! 

[niZmO_Man]

Bypass the boost controller. See how it goes then. Inspect those hoses.

[KLA33E]

I discovered yesterday that my actuator arm was stuck open, I pulled it a little and it came lose.

It seems to function to some extent, because if I pull it now the arm moves as it should.

Maybe time to go aftermatket? I will check if the WG port is fouling on something.

 

[Birds]

Is this manual or auto?

Vac line or intercooler piping/hose loose IMO...also inspect turbo actuator to see if it's not getting stuck open. If you're careful you can connect an air compressor to the actuator and /lightly/ introduce air to it - should open the flap.

[KLA33E]

29 minutes ago, Birds said:

Is this manual or auto?

Vac line or intercooler piping/hose loose IMO...also inspect turbo actuator to see if it's not getting stuck open. If you're careful you can connect an air compressor to the actuator and /lightly/ introduce air to it - should open the flap.

The car is Manual.

And yes the actuator was stuck open but managed to pull on it a little so it closed itself . It moves like it should now.

Seems to get stuck when I give it some.

I was thinking if the flap on the wastegate maybe got stuck on something in my downpipe, but never happend before so I don't know.

I will test drive today, see how it goes.

[inmaniac]

Yep, generally when your wastegate gets stuck open most of the time it's fouling on the dump pipe. Strange that it's happening out of nowhere though hmm... Perhaps the flapper has got loose and moved slightly over time?

There could also be an issue with the actuator itself but less likely.

Let us know how you go!

[Birds]

My next question was going to be...do you have a split type dump pipe? These are notorious for fouling wastegate flaps. I had the issue of mine being stuck shut with one, so it was boosting to infinity...had to grind away a lot of the dump pipe to clear it properly but it never fully resolved the issue until I had a custom bell mouth made up.

Heat is often the cause of dynamic problems (issues that seem sporadic or occur after a while of driving etc.). Good chance that once things heat up, the diaphragm in the actuator could be playing up, or the metal of the wastegate/pipe expands and fouls on the dump pipe. Heat will also cause any pipe/hose leaks to get worse or better.

Pull the actuator arm off the wastegate flap (little circlip can be popped off with a screwdriver). Then you can move the flap by hand. See if it catches or feels sticky. If not, you could replace your actuator to rule that out - can usually pick up second hand for $20 or so.

One thing to be careful of when a turbo isn't making boost, is revving the engine - if the wastegate is shut and it turns out to be an intercooler hose / intake leak you can overspin the turbo without realising it / it won't show up on boost gauge.

[KLA33E]

3 hours ago, Birds said:

My next question was going to be...do you have a split type dump pipe? These are notorious for fouling wastegate flaps. I had the issue of mine being stuck shut with one, so it was boosting to infinity...had to grind away a lot of the dump pipe to clear it properly but it never fully resolved the issue until I had a custom bell mouth made up.

Heat is often the cause of dynamic problems (issues that seem sporadic or occur after a while of driving etc.). Good chance that once things heat up, the diaphragm in the actuator could be playing up, or the metal of the wastegate/pipe expands and fouls on the dump pipe. Heat will also cause any pipe/hose leaks to get worse or better.

Pull the actuator arm off the wastegate flap (little circlip can be popped off with a screwdriver). Then you can move the flap by hand. See if it catches or feels sticky. If not, you could replace your actuator to rule that out - can usually pick up second hand for $20 or so.

One thing to be careful of when a turbo isn't making boost, is revving the engine - if the wastegate is shut and it turns out to be an intercooler hose / intake leak you can overspin the turbo without realising it / it won't show up on boost gauge.

Thank you for the answer!

Yes I've got a split dump pipe with a little piece of metal to separate the exhaust gases. So it's definetely a possibility 

I drove the car earlier. It was fine to begin with, since I got the arm free. Then when I accelerated with a bit off boost on to the highway it got stuck again.? 

So next up I will do what you said, separate the actuator arm from the flapper, and then I should be able to figure out where the problem lies..

[KLA33E]

Okay, it's been a while but i managed to fix the problem. 

It was indeed the metal piece in the downpipe that got the arm to get stuck open. Took the downpipe off and grinded a bit away and now the car goes much better than before. Feels like the spool is quicker too!

Cheers guys.

Edited July 11, 2017 by KLA33E