Ka-t no boost... - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Steve5405 · 08-16-2016, 03:31 PM

I have a freshly swapped/rebuilt dual cam Ka with a t3/t4. I just got the car running propperly, and was driving home from work when i heard a rather large pop and the car bucked a little. I figured an intercooler piping popped off, but they were all connected. I did notice the silicon adapter for the intake pre turbo had come off. Pulled that completly off and continued down the road. And to my demise, no boost. The gauge will just stop at 0. Since there is no intake, spooling is loudand obviously spooling. I disconected the bov to see if that was stuck open, but that made no difference. I have an external waste gate with an ebc, the waste gate is clearly not stuck open. I have looked everywhere for boost leaks and havent found ant, i do not have a tester though. I have 15ish pounds of vaccum at idle. So i feel like it shouldnt just be a boost leak. As expected the car does run slightly rich, but other than that, idles and drives well. Any help would be greatly appreciated. Turbo also free spins fine.

derass · 08-16-2016, 04:36 PM

You're going to have to pressurize the system to rule out a boost leak, a visual inspection doesn't cut it. Look up a DIY tester, it's a good tool to have.

Also, the unit for vacuum is "Inches of Mercury" (in.Hg), not pounds. 15 is very low unless you have cams.

KAT-PWR · 08-16-2016, 04:46 PM

Sounds like a coupler blew off

Steve5405 · 08-16-2016, 08:14 PM

Alright, will do. Ill update when i have pressure tested it.

About boost gauges reading vacuum in mmHg, is aways true? I just have an aem failsafe, so i can control what unit it is shown in. After light research I cant find a definate answer. and 14.7 psi would be a little less than 30 inHg which would make since.

Thanks for the quick reply guys.

vJilly · 08-16-2016, 08:46 PM

brake booster check valve

derass · 08-16-2016, 09:14 PM

You know what, you might be right. My Haltech was configured by default to read pressure and vacuum in PSI only. So 20 inHg would equal -9.8PSI.

However, if that's the case with your gauge -15 PSI would equal 30inHg as you said. It's nearly impossible that your engine would be pulling that much.

My advice is check the manual for your gauge. I'm sure it describes what units the values are.

Steve5405 · 08-17-2016, 02:15 PM

You were correct. It reads it in inHg; knowing this i surely have a vacuum leak. Sorry for the stupid question.

08-16-2016, 03:31 PM	#1
Steve5405 Leaky Injector Join Date: Apr 2013 Location: Richmond Age: 27 Posts: 64 Trader Rating: (4) Feedback Score: 4 reviews	Ka-t no boost... I have a freshly swapped/rebuilt dual cam Ka with a t3/t4. I just got the car running propperly, and was driving home from work when i heard a rather large pop and the car bucked a little. I figured an intercooler piping popped off, but they were all connected. I did notice the silicon adapter for the intake pre turbo had come off. Pulled that completly off and continued down the road. And to my demise, no boost. The gauge will just stop at 0. Since there is no intake, spooling is loudand obviously spooling. I disconected the bov to see if that was stuck open, but that made no difference. I have an external waste gate with an ebc, the waste gate is clearly not stuck open. I have looked everywhere for boost leaks and havent found ant, i do not have a tester though. I have 15ish pounds of vaccum at idle. So i feel like it shouldnt just be a boost leak. As expected the car does run slightly rich, but other than that, idles and drives well. Any help would be greatly appreciated. Turbo also free spins fine. Last edited by Steve5405; 08-16-2016 at 04:30 PM..

08-16-2016, 04:36 PM	#2
derass Zilvia FREAK! Join Date: Jun 2010 Location: Toronto, ON Age: 36 Posts: 1,182 Trader Rating: (0) Feedback Score: 0 reviews	You're going to have to pressurize the system to rule out a boost leak, a visual inspection doesn't cut it. Look up a DIY tester, it's a good tool to have. Also, the unit for vacuum is "Inches of Mercury" (in.Hg), not pounds. 15 is very low unless you have cams. Last edited by derass; 08-16-2016 at 09:08 PM..

08-16-2016, 04:46 PM	#3
KAT-PWR Nissanaholic! Join Date: Dec 2011 Location: US Posts: 2,040 Trader Rating: (11) Rides Gallery: KAT-PWR Feedback Score: 11 reviews	Sounds like a coupler blew off __________________ MRP Manufacturing

08-16-2016, 08:14 PM	#4
Steve5405 Leaky Injector Join Date: Apr 2013 Location: Richmond Age: 27 Posts: 64 Trader Rating: (4) Feedback Score: 4 reviews	Alright, will do. Ill update when i have pressure tested it. About boost gauges reading vacuum in mmHg, is aways true? I just have an aem failsafe, so i can control what unit it is shown in. After light research I cant find a definate answer. and 14.7 psi would be a little less than 30 inHg which would make since. Thanks for the quick reply guys.

08-16-2016, 09:14 PM	#6
derass Zilvia FREAK! Join Date: Jun 2010 Location: Toronto, ON Age: 36 Posts: 1,182 Trader Rating: (0) Feedback Score: 0 reviews	You know what, you might be right. My Haltech was configured by default to read pressure and vacuum in PSI only. So 20 inHg would equal -9.8PSI. However, if that's the case with your gauge -15 PSI would equal 30inHg as you said. It's nearly impossible that your engine would be pulling that much. My advice is check the manual for your gauge. I'm sure it describes what units the values are.

08-17-2016, 02:15 PM	#7
Steve5405 Leaky Injector Join Date: Apr 2013 Location: Richmond Age: 27 Posts: 64 Trader Rating: (4) Feedback Score: 4 reviews	You were correct. It reads it in inHg; knowing this i surely have a vacuum leak. Sorry for the stupid question.