Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Go Back   Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum > General > Tech Talk > Engine Tech

Engine Tech Technical discussion related to all relevant engines such as KA, SR, RB, CA, 2JZ , L24/26/28, VG, VQ, and LSx series.


Reply
 
Thread Tools Display Modes
Old 01-15-2014, 11:26 AM   #1
Nikzilla
Zilvia Member
 
Join Date: Jun 2013
Location: Los Angeles
Age: 26
Posts: 291
Trader Rating: (0)
Nikzilla is an unknown quantity at this point
Feedback Score: 0 reviews
[SR20DET] Are my rings fucked?

So my mechanical timing was off previously by 2 links on the camshaft sprockets and it was preventing my from setting my timing properly.

Previous thread:
http://zilvia.net/f/engine-tech/5494...iming-off.html

Now I'm really certain I have it dead on, there is 9 links between my camshaft marks, and the exhaust cam is dead on 12 o'clock relative to the engine block at TDC. Although I still can't get the timing in the right range, but I can get it at 15-16 BTDC with the CAS maxed out, however I can't get it to idle for shit.

It's stumbling and dying on me at idle, but if I just hold the throttle open it will run with a bit of a vibration, or if I advance the timing past -15 it runs smoothly. IACV was never adjusted, I was told that if it's stock, don't touch it.

I thought maybe my valves were bent since my cams were off, so I did a compression test.

Dry:
1. 150 psi (3 pumps for about 140psi, 6 pumps for 150)
2. 150 psi (3 pumps for about 140psi, 6 pumps for 150)
3. 135 psi (3 pumps for about 120psi, 6 pumps for 135)
4. 142 psi (3 pumps for about 130psi, 6 pumps for 142)

Wet (3 squirts of oil from a squirter):
1. 155 psi (3 pumps for about 140psi, 6 pumps for 155)
2. 170 psi (3 pumps for about 150psi, 6 pumps for 170) <<<<<<
3. 160 psi (3 pumps for about 145psi, 6 pumps for 160) <<<<<<
4. 160 psi (3 pumps for about 145psi, 6 pumps for 160)


In case you're wondering, the reason why my rocker cover was off is because I had lifter tick after mis-shifting 3rd to 2nd at high rpm. It was running fine beforehand.

Could my piston rings be fucked?
Nikzilla is offline   Reply With Quote
Sponsored Links
Old 01-15-2014, 11:36 AM   #2
pablito_s13
Leaky Injector
 
pablito_s13's Avatar
 
Join Date: May 2013
Location: Anaheim
Posts: 52
Trader Rating: (0)
pablito_s13 is an unknown quantity at this point
Feedback Score: 0 reviews
normal compression
pablito_s13 is offline   Reply With Quote
Old 01-15-2014, 11:39 AM   #3
Nikzilla
Zilvia Member
 
Join Date: Jun 2013
Location: Los Angeles
Age: 26
Posts: 291
Trader Rating: (0)
Nikzilla is an unknown quantity at this point
Feedback Score: 0 reviews
Quote:
Originally Posted by pablito_s13 View Post
normal compression
<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3

If you give me your address I will send you flowers
Nikzilla is offline   Reply With Quote
Old 01-15-2014, 12:17 PM   #4
pete240
Leaky Injector
 
Join Date: Mar 2007
Location: SATX
Age: 33
Posts: 124
Trader Rating: (4)
pete240 is making a name for him/her selfpete240 is making a name for him/her self
Feedback Score: 4 reviews
have you checked for boost/vac leaks?
pete240 is offline   Reply With Quote
Old 01-15-2014, 12:17 PM   #5
Nikzilla
Zilvia Member
 
Join Date: Jun 2013
Location: Los Angeles
Age: 26
Posts: 291
Trader Rating: (0)
Nikzilla is an unknown quantity at this point
Feedback Score: 0 reviews
Quote:
Originally Posted by pete240 View Post
have you checked for boost/vac leaks?
I had a couple but it's all air tight now.
Nikzilla is offline   Reply With Quote
Old 01-15-2014, 12:39 PM   #6
di-devol
Zilvia FREAK!
 
Join Date: Jun 2010
Location: Woodinville
Age: 39
Posts: 1,412
Trader Rating: (5)
di-devol will become famous soon enoughdi-devol will become famous soon enoughdi-devol will become famous soon enoughdi-devol will become famous soon enough
Feedback Score: 5 reviews
How are you taking timing with the gun? Are you using the loop at the back of the motor?

Take a pic of your cas, so we can see the orientation of it.
__________________
di-devol is offline   Reply With Quote
Old 01-15-2014, 01:19 PM   #7
Def
Post Whore!
 
Join Date: Apr 2004
Location: Houston, TX
Posts: 2,701
Trader Rating: (16)
Def is close to perfectionDef is close to perfectionDef is close to perfectionDef is close to perfectionDef is close to perfectionDef is close to perfectionDef is close to perfectionDef is close to perfectionDef is close to perfectionDef is close to perfectionDef is close to perfection
Feedback Score: 16 reviews
Do you have cams? If so you should open up the IACV screw slightly (maybe 1/2-1 full turns). Cams mean the engine needs more airflow at idle.

Have you checked a consult feed to see what your timing is vs. what the gun is reading? It should be pretty steady at 15 deg BTDC on almost any ROM tuned ECU, as most don't change the idle timing.

It'll jump a bit here and there to stabilize, which is the exhaust tone change you hear with an SR idling.
__________________
S13 Hatch - Goes around tracks quickly
DEFSPORT
Def is offline   Reply With Quote
Old 01-16-2014, 04:34 AM   #8
Luvs2slide
Zilvia FREAK!
 
Luvs2slide's Avatar
 
Join Date: Oct 2006
Location: NW Florida
Age: 39
Posts: 1,490
Trader Rating: (81)
Luvs2slide is a glorious beacon of lightLuvs2slide is a glorious beacon of lightLuvs2slide is a glorious beacon of lightLuvs2slide is a glorious beacon of lightLuvs2slide is a glorious beacon of lightLuvs2slide is a glorious beacon of lightLuvs2slide is a glorious beacon of lightLuvs2slide is a glorious beacon of lightLuvs2slide is a glorious beacon of lightLuvs2slide is a glorious beacon of lightLuvs2slide is a glorious beacon of light
Feedback Score: 81 reviews
You need to ensure your mechanical timing is set dead on. Your cam angle sensor should be roughly in the center of the adjustment. I made this picture after fighting with the timing on my car after doing it like 20 times for the first time, now its super easy. Good Luck.

__________________
Luvs2slide is offline   Reply With Quote
Old 01-16-2014, 05:00 PM   #9
Nikzilla
Zilvia Member
 
Join Date: Jun 2013
Location: Los Angeles
Age: 26
Posts: 291
Trader Rating: (0)
Nikzilla is an unknown quantity at this point
Feedback Score: 0 reviews
You guys have been extremely helpful! It turns out it was the IACV, even though my engine is stock. I just screwed it out a turn and it idled steady, and then I drew it back into 825 RPM.

Thanks guys!
Nikzilla is offline   Reply With Quote
Old 01-17-2014, 01:46 PM   #10
Def
Post Whore!
 
Join Date: Apr 2004
Location: Houston, TX
Posts: 2,701
Trader Rating: (16)
Def is close to perfectionDef is close to perfectionDef is close to perfectionDef is close to perfectionDef is close to perfectionDef is close to perfectionDef is close to perfectionDef is close to perfectionDef is close to perfectionDef is close to perfectionDef is close to perfection
Feedback Score: 16 reviews
Take the IACV out and clean it out with throttle body cleaner. They like to get gunk in them if you have any sort of blowby, especially on S13 SRs since the baffling in the valve cover sucks.
__________________
S13 Hatch - Goes around tracks quickly
DEFSPORT
Def is offline   Reply With Quote
Reply

Bookmarks


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 04:48 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
vB.Sponsors
Copyright © 1998 - 2019, Zilvia.net™