Vacuum leak please help (pic) - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

todd5854 · 02-01-2013, 05:42 PM

Very loud and obvious.

If I spray starter fluid in the circled red area, my idle goes back to normal for a bit.

idle is rough, low, and the entire engine shakes. It almost sounds like a misfire... when I rev past 1500 the misfire type sound goes away.

Sometimes when coasting, I push in the clutch, it'll stay around 2000rpm to 2500 for a few seconds then drop to 500 - 700

20130201_193454 by todd5854, on Flickr

todd5854 · 02-01-2013, 05:46 PM

Note-

I know there are no hoses on my egr. I removed the BPT and plugged the vacuums going to it / them. EGR is next to go. Also that hose with no clamps on it... that hose is not leaking. It is mangled and will be replaced. Car has been running fine for 5 months, this problem came up a week ago and I still can't figure it out.

godsmack · 02-01-2013, 07:02 PM

Manifold gasket or injector o-ring. I'm leaning more towards the manifold gasket being shot there. Get new gasket and replace.

steve shadows · 02-01-2013, 07:11 PM

Here's a way to know for sure: DIY How-to: build a vacuum leak detection machine - Pennock's Fiero Forum

todd5854 · 02-01-2013, 07:27 PM

I already replaced my intake manifold a few months ago. New gasket obviously lol.

My o ring gaskets are hard as rock. They can be changed.

Other symptoms..
Driving just above 2000rpm if I push clutch in the revs go to 2500 then drops to idle.

Sprayed starter fluid on injector no. 4 and idle went smooth for short time

At wide open throttle (WOT) I hear whining from 3k to about 6k

Frank_Jaeger · 02-01-2013, 08:34 PM

Quote:

Originally Posted by todd5854

I already replaced my intake manifold a few months ago. New gasket obviously lol.

My o ring gaskets are hard as rock. They can be changed.

Other symptoms..
Driving just above 2000rpm if I push clutch in the revs go to 2500 then drops to idle.

Sprayed starter fluid on injector no. 4 and idle went smooth for short time

At wide open throttle (WOT) I hear whining from 3k to about 6k

Doesn't mean jack if the manifold isn't flush with the head. Did you reinstall the braces for the lower manifold?

EDIT: If you're getting new o-rings, you can get them from FRSport. http://www.frsport.com/OEM-Upper-and...ts_p_1325.html

todd5854 · 02-02-2013, 10:16 AM

The braces... those 3 14mm bolts? Only one would go in.

I purchased new o-rings, and seals for the 4 injectors for $20.

Mine are hard as a rock so it won't hurt to just change them anyway.. when I swapped manifolds I reused them too, that's two strikes against those shitty ones.

I agree with you, it seems like it would be a leak from my manifold..hopefully not a crack.
I have another one I can put in if all else fails.

todd5854 · 02-02-2013, 01:33 PM

Oh by the way, when the car is COLD the idle is normal.

Frank_Jaeger · 02-02-2013, 01:45 PM

Did you install that one bolt for the brace before or after you bolted the IM to the head?

When the car idles cold it's usually running at a high enough RPM that a vac leak isn't apparent.

todd5854 · 02-02-2013, 09:21 PM

Brace installed after bolted to head. and yeah that makes sense.

cold it idles at 1000 now (this is also normal)

warm it idles 400- 1100 its all over the fucking place

todd5854 · 02-02-2013, 11:35 PM

injector o-rings and seals for all 4 injectors are on the way. Getting my intake manifold ready for replacement..... gonna order those gaskets as well.

Would anyone recommend changing the knock sensor? It's like $60 but I don't want to spend the money if I don't have to... my 94 ecu had CEL for knock sensor, but when I swapped manual, the 92 ecu is throwing no codes.

02-01-2013, 05:42 PM	#1
todd5854 Leaky Injector Join Date: Nov 2012 Location: Pennsylvania Posts: 144 Trader Rating: (0) Feedback Score: 0 reviews	Vacuum leak please help (pic) Very loud and obvious. If I spray starter fluid in the circled red area, my idle goes back to normal for a bit. idle is rough, low, and the entire engine shakes. It almost sounds like a misfire... when I rev past 1500 the misfire type sound goes away. Sometimes when coasting, I push in the clutch, it'll stay around 2000rpm to 2500 for a few seconds then drop to 500 - 700 20130201_193454 by todd5854, on Flickr

02-01-2013, 07:11 PM	#4
steve shadows Post Whore! Join Date: Aug 2003 Location: LA and OC Posts: 8,202 Trader Rating: (5) Feedback Score: 5 reviews	Here's a way to know for sure: DIY How-to: build a vacuum leak detection machine - Pennock's Fiero Forum __________________ Like Me on FaceBook !

02-01-2013, 05:46 PM	#2
todd5854 Leaky Injector Join Date: Nov 2012 Location: Pennsylvania Posts: 144 Trader Rating: (0) Feedback Score: 0 reviews	Note- I know there are no hoses on my egr. I removed the BPT and plugged the vacuums going to it / them. EGR is next to go. Also that hose with no clamps on it... that hose is not leaking. It is mangled and will be replaced. Car has been running fine for 5 months, this problem came up a week ago and I still can't figure it out.

02-01-2013, 07:02 PM	#3
godsmack Zilvia Addict Join Date: Feb 2009 Location: Allentown, PA Age: 38 Posts: 652 Trader Rating: (0) Feedback Score: 0 reviews	Manifold gasket or injector o-ring. I'm leaning more towards the manifold gasket being shot there. Get new gasket and replace.

02-01-2013, 07:27 PM	#5
todd5854 Leaky Injector Join Date: Nov 2012 Location: Pennsylvania Posts: 144 Trader Rating: (0) Feedback Score: 0 reviews	I already replaced my intake manifold a few months ago. New gasket obviously lol. My o ring gaskets are hard as rock. They can be changed. Other symptoms.. Driving just above 2000rpm if I push clutch in the revs go to 2500 then drops to idle. Sprayed starter fluid on injector no. 4 and idle went smooth for short time At wide open throttle (WOT) I hear whining from 3k to about 6k

02-02-2013, 10:16 AM	#7
todd5854 Leaky Injector Join Date: Nov 2012 Location: Pennsylvania Posts: 144 Trader Rating: (0) Feedback Score: 0 reviews	The braces... those 3 14mm bolts? Only one would go in. I purchased new o-rings, and seals for the 4 injectors for $20. Mine are hard as a rock so it won't hurt to just change them anyway.. when I swapped manifolds I reused them too, that's two strikes against those shitty ones. I agree with you, it seems like it would be a leak from my manifold..hopefully not a crack. I have another one I can put in if all else fails.

02-02-2013, 01:33 PM	#8
todd5854 Leaky Injector Join Date: Nov 2012 Location: Pennsylvania Posts: 144 Trader Rating: (0) Feedback Score: 0 reviews	Oh by the way, when the car is COLD the idle is normal.

02-02-2013, 01:45 PM	#9
Frank_Jaeger Zilvia FREAK! Join Date: Jan 2012 Location: Port Charlotte, Florida Age: 32 Posts: 1,352 Trader Rating: (1) Feedback Score: 1 reviews	Did you install that one bolt for the brace before or after you bolted the IM to the head? When the car idles cold it's usually running at a high enough RPM that a vac leak isn't apparent.

02-02-2013, 09:21 PM	#10
todd5854 Leaky Injector Join Date: Nov 2012 Location: Pennsylvania Posts: 144 Trader Rating: (0) Feedback Score: 0 reviews	Brace installed after bolted to head. and yeah that makes sense. cold it idles at 1000 now (this is also normal) warm it idles 400- 1100 its all over the fucking place

02-02-2013, 11:35 PM	#11
todd5854 Leaky Injector Join Date: Nov 2012 Location: Pennsylvania Posts: 144 Trader Rating: (0) Feedback Score: 0 reviews	injector o-rings and seals for all 4 injectors are on the way. Getting my intake manifold ready for replacement..... gonna order those gaskets as well. Would anyone recommend changing the knock sensor? It's like $60 but I don't want to spend the money if I don't have to... my 94 ecu had CEL for knock sensor, but when I swapped manual, the 92 ecu is throwing no codes.