Won't build boost? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Solidus311 · 07-16-2008, 05:12 PM

My rb25 won't build boost. My gauge reads vacuum then goes to 0 and no further. I bought a used OEM wastegate but I am being told that it could be the turbo itself. I checked all my piping and I don't think there are any leaks. I have yet to do a boost leak test though.

Prior to losing boost I was doing a little clutch kicking.

I have an SAFC with fuel turned down 10-22 percent, and a manual boost controller set to about 12 LBs. Car has trouble running at all, much less with boost. Seems to be running super rich, it bogs down and can hardly make it to 4k RPM's.

What about the ECU wiring? I had someone with me at the time and maybe he kicked the kick panel and fucked up my ECU.

kevtrinh · 07-16-2008, 06:02 PM

sounds like boost leak

Solidus311 · 07-16-2008, 08:24 PM

Quote:

Originally Posted by kevtrinh

sounds like boost leak

Alright, I guess I'll rig up something to test for a leak before I drop the money for a turbo.

*fliprayzin240sx* · 07-17-2008, 12:39 AM

Check the tubo too, not that hard to check it. Take the inlet off and spin the compressor by hand.

Solidus311 · 07-17-2008, 01:11 AM

Quote:

Originally Posted by fliprayzin240sx

Check the tubo too, not that hard to check it. Take the inlet off and spin the compressor by hand.

Compressor side seems fine, spins freely and not a lot of play. I haven't checked the exhaust side.

awesomenick · 07-17-2008, 01:28 AM

Both wheels on the turbo are connected on a solid shaft. Normally a problem with the turbo would be in the center section, so you probably don't need to check the exhaust side too. If it spins and doesn't have excessive shaft play through the intake side, it's probably not causing your issues. It sounds a lot like a boost leak, maybe one of your couplers popped off, or has a tear in it. You should build a boost leak tester, and also use some soapy water on all connections to make sure it's perfect.

When you have a boost leak, you're leaking out metered air. This would cause the MAFS readings to be totally incorrect, and that could be why your car hardly runs.

Solidus311 · 07-18-2008, 01:40 AM

Quote:

Originally Posted by awesomenick

Both wheels on the turbo are connected on a solid shaft. Normally a problem with the turbo would be in the center section, so you probably don't need to check the exhaust side too. If it spins and doesn't have excessive shaft play through the intake side, it's probably not causing your issues. It sounds a lot like a boost leak, maybe one of your couplers popped off, or has a tear in it. You should build a boost leak tester, and also use some soapy water on all connections to make sure it's perfect.

When you have a boost leak, you're leaking out metered air. This would cause the MAFS readings to be totally incorrect, and that could be why your car hardly runs.

Man I hope you're right. Fixing a boost leak is far cheaper than a used/new turbo.

07-16-2008, 05:12 PM	#1
Solidus311 Leaky Injector Join Date: May 2008 Location: MD Age: 37 Posts: 97 Trader Rating: (0) Feedback Score: 0 reviews	Won't build boost? My rb25 won't build boost. My gauge reads vacuum then goes to 0 and no further. I bought a used OEM wastegate but I am being told that it could be the turbo itself. I checked all my piping and I don't think there are any leaks. I have yet to do a boost leak test though. Prior to losing boost I was doing a little clutch kicking. I have an SAFC with fuel turned down 10-22 percent, and a manual boost controller set to about 12 LBs. Car has trouble running at all, much less with boost. Seems to be running super rich, it bogs down and can hardly make it to 4k RPM's. What about the ECU wiring? I had someone with me at the time and maybe he kicked the kick panel and fucked up my ECU. __________________ cardomain.com/ride/3113705

07-16-2008, 06:02 PM	#2
kevtrinh Zilvia Junkie Join Date: May 2006 Location: Richmond,VA Posts: 370 Trader Rating: (0) Feedback Score: 0 reviews	sounds like boost leak __________________ Team Pterodactyl

07-17-2008, 12:39 AM	#4
fliprayzin240sx Man w/ CTSV & a Car Seat Join Date: Aug 2002 Location: Tampa Posts: 17,998 Trader Rating: (19) Rides Gallery: fliprayzin240sx Feedback Score: 19 reviews	Check the tubo too, not that hard to check it. Take the inlet off and spin the compressor by hand. __________________ If you think Zilvia has too many assholes... CLICK HERE!!!

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07-17-2008, 01:28 AM	#6
awesomenick Zilvia Addict Join Date: May 2006 Location: UT Age: 32 Posts: 944 Trader Rating: (33) Feedback Score: 33 reviews	Both wheels on the turbo are connected on a solid shaft. Normally a problem with the turbo would be in the center section, so you probably don't need to check the exhaust side too. If it spins and doesn't have excessive shaft play through the intake side, it's probably not causing your issues. It sounds a lot like a boost leak, maybe one of your couplers popped off, or has a tear in it. You should build a boost leak tester, and also use some soapy water on all connections to make sure it's perfect. When you have a boost leak, you're leaking out metered air. This would cause the MAFS readings to be totally incorrect, and that could be why your car hardly runs.