vac. pressure good sometimes??? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

sk8rfreak345 · 10-22-2012, 05:01 PM

I have a ka24det running weird.

9 out of 10 times I start it, the vacuum gauge reads -17, idles sputtering, running really rich, black smoke. (when i try to accelerate it doesn't hold boost)

that other 1/10 times it will start up perfect, vacuum at -23, perfect idle, no smoke, holds boost almost perfectly (~6psi.).

i have 2 separate maf's that i have tried with no success. checked for leaks and fixed them except a small one by the iacv.

So what could be causing it to work right occasionally? any suggestions?(seems it would be something electrical.) thanks in advance for any helpful comments, and yes i have searched, cant find any cases that completely match mine.

if it helps at all its has a s14 t28, sr injectors, an n60 maf and an Enthalpy tune.

sk8rfreak345 · 10-25-2012, 06:48 PM

no one has a clue?

bkt808 · 10-25-2012, 10:53 PM

my rb was doing this, it was a loose fuel rail causing a vacuum leak at the injector to manifold o-rings. sometimes the vacuum would seal the injectors to the rings and idle good and when id hit boost it would open up the leak and idle bad when it came back down to idle

sk8rfreak345 · 10-26-2012, 10:32 AM

Yea I didn't notice a vacuum leak at the insulators but I'll go ahead and replace them and see what happens. Thanks!

10-22-2012, 05:01 PM	#1
sk8rfreak345 Leaky Injector Join Date: Aug 2009 Location: Long Beach Age: 28 Posts: 59 Trader Rating: (4) Feedback Score: 4 reviews	vac. pressure good sometimes??? I have a ka24det running weird. 9 out of 10 times I start it, the vacuum gauge reads -17, idles sputtering, running really rich, black smoke. (when i try to accelerate it doesn't hold boost) that other 1/10 times it will start up perfect, vacuum at -23, perfect idle, no smoke, holds boost almost perfectly (~6psi.). i have 2 separate maf's that i have tried with no success. checked for leaks and fixed them except a small one by the iacv. So what could be causing it to work right occasionally? any suggestions?(seems it would be something electrical.) thanks in advance for any helpful comments, and yes i have searched, cant find any cases that completely match mine. if it helps at all its has a s14 t28, sr injectors, an n60 maf and an Enthalpy tune.

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10-25-2012, 06:48 PM	#2
sk8rfreak345 Leaky Injector Join Date: Aug 2009 Location: Long Beach Age: 28 Posts: 59 Trader Rating: (4) Feedback Score: 4 reviews	no one has a clue?

10-25-2012, 10:53 PM	#3
bkt808 Zilvia Member Join Date: Feb 2010 Location: Wailuku, Maui, Hawaii Age: 33 Posts: 245 Trader Rating: (1) Feedback Score: 1 reviews	my rb was doing this, it was a loose fuel rail causing a vacuum leak at the injector to manifold o-rings. sometimes the vacuum would seal the injectors to the rings and idle good and when id hit boost it would open up the leak and idle bad when it came back down to idle

10-26-2012, 10:32 AM	#4
sk8rfreak345 Leaky Injector Join Date: Aug 2009 Location: Long Beach Age: 28 Posts: 59 Trader Rating: (4) Feedback Score: 4 reviews	Yea I didn't notice a vacuum leak at the insulators but I'll go ahead and replace them and see what happens. Thanks!