S14SR forgot how to turbo. Help needed. - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

LongGrain · 05-31-2017, 07:29 AM

Hey dudes, long time no post. I'm trying to help my friend figure out a problem we're having with his SR. We were driving at an event on Sunday and all of the sudden his car decided it didn't want to be turbo anymore and just started running NA.. I've searched and came up with threads with the same problem but all seemed to end up being a problem we don't have.

Engine setup:
Stock s14sr
High/mid mount intercooler
3" downpipe
Tomei poncam
Ran perfect one lap, then just decided to be NA the next
Runs GREAT, and is totally drivable and normal sounding, aside from not having the power it should.

Things I've checked:
Wastegate actuator (and replaced it with a new one.. no change)
Wastegate - flapper and door are present and move freely
Compressor and turbine wheels are both present and spin together (shaft not snapped or anything)
Turbo has a little shaft play since its old, but nothing that would condemn it.
Turbo IS spinning just fine with the engine running, you can hear it doing its thing
Blow off valve opens and closes properly
Wastegate is closed and has tension on it
All piping/hoses are hooked up, no boost/vacuum leaks that I have found
Haven't taken the turbo off to inspect for exhaust leaks pre-turbo, but all hardware is tight and the gaskets were all new recently.
Cam and ignition timing were done recently and should still be fine
AFR's were good both before and after it started having this issue.

I'm completely stumped. If you have any insight as to why it wouldn't make any boost, I'd love to hear it.

jedi03 · 05-31-2017, 08:05 AM

temp sensor, fuel pressure, spark plugs, compression...um that's all I can think of atm

LongGrain · 05-31-2017, 09:00 AM

All of those things are new. Compression is good. The car runs and drives literally perfect, it's just NA. It was perfectly fine one run, waited in the grid, went for his next lap and all of the sudden it didn't boost, just ripped like a Sentra haha.

LongGrain · 05-31-2017, 09:01 AM

Also, no codes on the ecu or anything via Consult

***Future240*** · 05-31-2017, 02:42 PM

Tried swapping in another ECU?

blackmags91 · 05-31-2017, 02:56 PM

Does he have a mechanical boost gauge hooked up? You've said its not boosting, but it sounds totally fine? Is there any positive charge being measured?

914Slide · 05-31-2017, 07:29 PM

Quote:

Originally Posted by blackmags91

Does he have a mechanical boost gauge hooked up? You've said its not boosting, but it sounds totally fine? Is there any positive charge being measured?

Agreed what does the gauge say? make sure it is showing neg pressure at idle. what are the afrs at wot? it could be leaning out

Maybe the turbo had some crazy failure.

LongGrain · 05-31-2017, 08:12 PM

Wot AFR is normal, around 11.5 iirc. Yes it has a boost gauge, does not build any pressure. Car runs and feels fine, but it is NA. Turbo has not suffered any sort of catastrophic failure. All components are there and spin freely. Engine pulls perfect vacuum

Even with the wastegate line pulled off (wastegate stuck closed), the car does not build any boost.

LongGrain · 05-31-2017, 09:28 PM

Just popped the valve cover off, cam timing didn't jump or anything. All looks good on the inside

Jefro240 · 06-01-2017, 09:59 AM

Quote:

Originally Posted by LongGrain

Haven't taken the turbo off to inspect for exhaust leaks pre-turbo, but all hardware is tight and the gaskets were all new recently.

This is where I'd start. If the gasket between the manifold & turbo is toast resulting in a huge leak you will not see any boost.

bataangpinoy · 06-01-2017, 10:37 AM

i've had the seals of a turbo fail and push boost through the shaft seals instead of through the compressor housing. one was on my s13 sr, the other is a buddy's rb20. made boost fine one day, intermittent/none the next.

di-devol · 06-05-2017, 06:12 PM

Quote:

Originally Posted by LongGrain

Wot AFR is normal, around 11.5 iirc. Yes it has a boost gauge, does not build any pressure. Car runs and feels fine, but it is NA. Turbo has not suffered any sort of catastrophic failure. All components are there and spin freely. Engine pulls perfect vacuum

Even with the wastegate line pulled off (wastegate stuck closed), the car does not build any boost.

If you're not boosting how are the afr's correct? You'd be super rich. Sure it ain't the clutch? Check timing with a light.

LongGrain · 06-05-2017, 07:29 PM

Quote:

Originally Posted by di-devol

If you're not boosting how are the afr's correct? You'd be super rich. Sure it ain't the clutch? Check timing with a light.

You wouldn't necessarily be rich unless it was a boost leak. The MAF reads the quantity of air coming in and tells the ecu how much fuel to send, so long as the MAF is reading the correct amount of air it doesn't matter if you're making boost or not.

Anyways, found the issue. Someone decided to play some kind of sick joke and shove a bunch of paper in his intercooler. It was blocking all the airflow. Pulled it out and it's back to normal.

di-devol · 06-06-2017, 12:54 AM

Quote:

Originally Posted by LongGrain

You wouldn't necessarily be rich unless it was a boost leak. The MAF reads the quantity of air coming in and tells the ecu how much fuel to send, so long as the MAF is reading the correct amount of air it doesn't matter if you're making boost or not.

Anyways, found the issue. Someone decided to play some kind of sick joke and shove a bunch of paper in his intercooler. It was blocking all the airflow. Pulled it out and it's back to normal.

Oh, you're right. Derp.

jedi03 · 06-06-2017, 03:57 PM

Man good thing it didn't get in the engine! Would have been a bad day!

05-31-2017, 07:29 AM	#1
LongGrain Post Whore! Join Date: Sep 2006 Location: Midwest Posts: 2,741 Trader Rating: (5) Feedback Score: 5 reviews	S14SR forgot how to turbo. Help needed. Hey dudes, long time no post. I'm trying to help my friend figure out a problem we're having with his SR. We were driving at an event on Sunday and all of the sudden his car decided it didn't want to be turbo anymore and just started running NA.. I've searched and came up with threads with the same problem but all seemed to end up being a problem we don't have. Engine setup: Stock s14sr High/mid mount intercooler 3" downpipe Tomei poncam Ran perfect one lap, then just decided to be NA the next Runs GREAT, and is totally drivable and normal sounding, aside from not having the power it should. Things I've checked: Wastegate actuator (and replaced it with a new one.. no change) Wastegate - flapper and door are present and move freely Compressor and turbine wheels are both present and spin together (shaft not snapped or anything) Turbo has a little shaft play since its old, but nothing that would condemn it. Turbo IS spinning just fine with the engine running, you can hear it doing its thing Blow off valve opens and closes properly Wastegate is closed and has tension on it All piping/hoses are hooked up, no boost/vacuum leaks that I have found Haven't taken the turbo off to inspect for exhaust leaks pre-turbo, but all hardware is tight and the gaskets were all new recently. Cam and ignition timing were done recently and should still be fine AFR's were good both before and after it started having this issue. I'm completely stumped. If you have any insight as to why it wouldn't make any boost, I'd love to hear it.

05-31-2017, 08:05 AM	#2
jedi03 Nissanaholic! Join Date: Jul 2008 Location: albuquerque Posts: 1,836 Trader Rating: (8) Feedback Score: 8 reviews	temp sensor, fuel pressure, spark plugs, compression...um that's all I can think of atm

05-31-2017, 09:00 AM	#3
LongGrain Post Whore! Join Date: Sep 2006 Location: Midwest Posts: 2,741 Trader Rating: (5) Feedback Score: 5 reviews	All of those things are new. Compression is good. The car runs and drives literally perfect, it's just NA. It was perfectly fine one run, waited in the grid, went for his next lap and all of the sudden it didn't boost, just ripped like a Sentra haha.

05-31-2017, 09:01 AM	#4
LongGrain Post Whore! Join Date: Sep 2006 Location: Midwest Posts: 2,741 Trader Rating: (5) Feedback Score: 5 reviews	Also, no codes on the ecu or anything via Consult

05-31-2017, 02:56 PM	#6
blackmags91 Zilvia Member Join Date: Sep 2010 Location: Phoenix, AZ Posts: 225 Trader Rating: (1) Feedback Score: 1 reviews	Does he have a mechanical boost gauge hooked up? You've said its not boosting, but it sounds totally fine? Is there any positive charge being measured?

05-31-2017, 08:12 PM	#8
LongGrain Post Whore! Join Date: Sep 2006 Location: Midwest Posts: 2,741 Trader Rating: (5) Feedback Score: 5 reviews	Wot AFR is normal, around 11.5 iirc. Yes it has a boost gauge, does not build any pressure. Car runs and feels fine, but it is NA. Turbo has not suffered any sort of catastrophic failure. All components are there and spin freely. Engine pulls perfect vacuum Even with the wastegate line pulled off (wastegate stuck closed), the car does not build any boost.

05-31-2017, 09:28 PM	#9
LongGrain Post Whore! Join Date: Sep 2006 Location: Midwest Posts: 2,741 Trader Rating: (5) Feedback Score: 5 reviews	Just popped the valve cover off, cam timing didn't jump or anything. All looks good on the inside

06-06-2017, 03:57 PM	#15
jedi03 Nissanaholic! Join Date: Jul 2008 Location: albuquerque Posts: 1,836 Trader Rating: (8) Feedback Score: 8 reviews	Man good thing it didn't get in the engine! Would have been a bad day!