boost problem?! please help - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

DrIvEsldEwAyS · 10-12-2007, 11:03 PM

car was running great, had to take out the turbo and exhaust manifold to replace the exhaust gaskets, put it back in and whenever the boost controller is cut on (low or high boost) it will hold boost untill around 6k rpms and then the wastegate will shut. feels like hitting speed limiter. when you turn the boost controller off this problem does not occur. we have messed with the settings to try and fix it and no luck. any ideas?

we have tripple checked everything we unplugged and made sure its all hooked back up (o2 sensor, vaccum to wastegate and maf.) other then that we didnt touch anything when taking the turbo off.

DrIvEsldEwAyS · 10-13-2007, 05:18 PM

no one have any imput?

slider2828 · 10-13-2007, 05:36 PM

chances are its your gaskets..... hopefully you didn't reuse any of them? Secondly, try to tighten all of them. Wastegate shuts to hold boost and opens to reduce boost. So you probably have a small exhaust leak.

DrIvEsldEwAyS · 10-13-2007, 11:45 PM

i had a exhaust leak before and we fixed that. brand new OEM metal gaskets. we put a different boost controll solinoid on it and still did it. erased all the settings and started from 0 and started cutting again from 12-15psi.

skylindrftr · 10-14-2007, 12:57 AM

make sure your hotpipe is on there good, that is the only charge pipe you should have had to take off to remove the turbo, you might be leaking boost from a coupler or something check for holes, if you still dont find it, do a boost leak test.

DrIvEsldEwAyS · 10-14-2007, 07:37 AM

but if it was a boost leak why does it not do it at 10psi but do it at 14?

DrIvEsldEwAyS · 10-15-2007, 08:39 PM

still cant find it. any other ideas?

Gjohnson7 · 10-15-2007, 08:54 PM

I would assume it would be because of the increased pressure. 10 psi might not be enought pressure for it to leak???

Quote:

Originally Posted by DrIvEsldEwAyS

but if it was a boost leak why does it not do it at 10psi but do it at 14?

mangoes · 12-01-2007, 03:07 AM

sorry to bring back this thread but, i did pretty much the exact same thing tonight. the gasket on the turbo inlet went bad so we replaced it. had to take off exhaust manifold, unbolt turbo from manifold, unbolted the downpipe, took out hotpipe, took out intake, etc. we put everything back.

i am having the same problem. i hit boost cut whenever i hit .5-.6 bar. im running power fc w/ power fc boost controller. can the gaskets really cause the car to hit boost cut? we checked all the couplers on everything and they are all tight.

10-12-2007, 11:03 PM	#1
DrIvEsldEwAyS Zilvia Junkie Join Date: Apr 2005 Location: Columbia,SC Age: 35 Posts: 351 Trader Rating: (0) Feedback Score: 0 reviews	boost problem?! please help car was running great, had to take out the turbo and exhaust manifold to replace the exhaust gaskets, put it back in and whenever the boost controller is cut on (low or high boost) it will hold boost untill around 6k rpms and then the wastegate will shut. feels like hitting speed limiter. when you turn the boost controller off this problem does not occur. we have messed with the settings to try and fix it and no luck. any ideas? we have tripple checked everything we unplugged and made sure its all hooked back up (o2 sensor, vaccum to wastegate and maf.) other then that we didnt touch anything when taking the turbo off. __________________ -1990 240sx hatch sr20det- gt35r, blah blah blah

10-13-2007, 05:18 PM	#2
DrIvEsldEwAyS Zilvia Junkie Join Date: Apr 2005 Location: Columbia,SC Age: 35 Posts: 351 Trader Rating: (0) Feedback Score: 0 reviews	no one have any imput? __________________ -1990 240sx hatch sr20det- gt35r, blah blah blah

10-13-2007, 05:36 PM	#3
slider2828 Post Whore! Join Date: Oct 2004 Location: San Francisco, CA Posts: 5,998 Trader Rating: (13) Feedback Score: 13 reviews	chances are its your gaskets..... hopefully you didn't reuse any of them? Secondly, try to tighten all of them. Wastegate shuts to hold boost and opens to reduce boost. So you probably have a small exhaust leak. __________________ Turn and Burn!

10-13-2007, 11:45 PM	#4
DrIvEsldEwAyS Zilvia Junkie Join Date: Apr 2005 Location: Columbia,SC Age: 35 Posts: 351 Trader Rating: (0) Feedback Score: 0 reviews	i had a exhaust leak before and we fixed that. brand new OEM metal gaskets. we put a different boost controll solinoid on it and still did it. erased all the settings and started from 0 and started cutting again from 12-15psi. __________________ -1990 240sx hatch sr20det- gt35r, blah blah blah

10-14-2007, 07:37 AM	#6
DrIvEsldEwAyS Zilvia Junkie Join Date: Apr 2005 Location: Columbia,SC Age: 35 Posts: 351 Trader Rating: (0) Feedback Score: 0 reviews	but if it was a boost leak why does it not do it at 10psi but do it at 14? __________________ -1990 240sx hatch sr20det- gt35r, blah blah blah

10-14-2007, 12:57 AM	#5
skylindrftr Zilvia FREAK! Join Date: Apr 2007 Location: Metro Detroit Age: 35 Posts: 1,099 Trader Rating: (26) Feedback Score: 26 reviews	make sure your hotpipe is on there good, that is the only charge pipe you should have had to take off to remove the turbo, you might be leaking boost from a coupler or something check for holes, if you still dont find it, do a boost leak test.

10-15-2007, 08:39 PM	#7
DrIvEsldEwAyS Zilvia Junkie Join Date: Apr 2005 Location: Columbia,SC Age: 35 Posts: 351 Trader Rating: (0) Feedback Score: 0 reviews	still cant find it. any other ideas? __________________ -1990 240sx hatch sr20det- gt35r, blah blah blah

12-01-2007, 03:07 AM	#9
mangoes Zilvia Addict Join Date: Oct 2005 Location: SF Age: 33 Posts: 967 Trader Rating: (16) Feedback Score: 16 reviews	sorry to bring back this thread but, i did pretty much the exact same thing tonight. the gasket on the turbo inlet went bad so we replaced it. had to take off exhaust manifold, unbolt turbo from manifold, unbolted the downpipe, took out hotpipe, took out intake, etc. we put everything back. i am having the same problem. i hit boost cut whenever i hit .5-.6 bar. im running power fc w/ power fc boost controller. can the gaskets really cause the car to hit boost cut? we checked all the couplers on everything and they are all tight. __________________ Outside Family