Computer Diagnostics and Tuning Technical discussion on diagnostics and programming of the F-body computers

1995 Z28 pinging under load once warmed up

Thread Tools
 
Search this Thread
 
Old Jun 24, 2010 | 01:15 PM
  #16  
bobdec's Avatar
Registered User
 
Joined: Nov 2007
Posts: 910
xxjman, is you PVC valve OK, during normal (high) vacuum conditions the hose from valve cover to the TB should be sucking fresh metered air out of the TB into the valve cover, thru the crankcase/lifter galley where it becomes crankcase fumes and then the fumes end up in the intake thru the PVC valve. To test.. when idling pull the hose off the valve cover and place a piece of paper (bigger than the hole so it doesn't get sucked in) to test for vacuum, if the paper does not get sucked down then you have positive pressure in the crankcase or a PVC problem.
Old Jun 24, 2010 | 01:23 PM
  #17  
xxjman's Avatar
Thread Starter
Registered User
 
Joined: Dec 2006
Posts: 18
From: Leander, Texas
I did replace that when I did the heads but that doesn't mean it's not bad so I will try that test and see what I get. I am hoping it's something simple.

That would make sense though because I wasn't going through oil like I am now and it is not leaking. Sometimes when I start the car I get a nice white smoke cloud. One time the car did not start right away like it normally does when I tried to start it again it turned over a bunch of times and then a huge white cloud came out from under the hood. This was strange I have never seen this happen before. So it does make me think that the intake is filling up with oil.

Thanks for the help
Old Jun 24, 2010 | 05:51 PM
  #18  
Injuneer's Avatar
Administrator
 
Joined: Nov 1998
Posts: 71,094
From: Hell was full so they sent me to NJ
PCV valve
Old Jun 24, 2010 | 06:43 PM
  #19  
xxjman's Avatar
Thread Starter
Registered User
 
Joined: Dec 2006
Posts: 18
From: Leander, Texas
Well I just went out on lunch break "I work late!" And did the paper test on the vent line passenger valve cover and it did not suck the paper in I put my finger on it and could feel just a little bit of suction but nothing major. The elbow is covered in oil though. So I guess the next step will be pulling the pcv out. Can I run it without that venting connected to test? See if it helps the ping go away? Also this was after a cold start I don't know if that matters? I wouldn't think so but that's why I am asking.

Thanks guys
Old Jun 24, 2010 | 09:40 PM
  #20  
Injuneer's Avatar
Administrator
 
Joined: Nov 1998
Posts: 71,094
From: Hell was full so they sent me to NJ
If you pull the vent hose off, cap the connection on the side of the throttle body. Also put a small filter in the hose to the valve cover, so you don't pull dirty air in.

Some people add a small 90-degree Deutsch filter that replaces the plastic elbow that connects the hose to the valve cover. I'm not sure how long that will last without plugging up if you have a heay oil load through the hose. Clean out the top of the throttle body, under the cover plate. That's where the vent hose connects.
Old Jun 24, 2010 | 09:52 PM
  #21  
xxjman's Avatar
Thread Starter
Registered User
 
Joined: Dec 2006
Posts: 18
From: Leander, Texas
Ok I will try that. I have read about those filters. I have read a lot. I am determined to fix this thing one way or another!

Thanks for the help
Old Jun 30, 2010 | 11:56 AM
  #22  
xxjman's Avatar
Thread Starter
Registered User
 
Joined: Dec 2006
Posts: 18
From: Leander, Texas
Ok I changed out the pcv and added the filter to the valve cover and cleaned out the top of the TB. I also disconnected the battery to reset the pcm. 2nd day of driving no more smoke and no more pinging!!!

Now I guess I can get a tune for it.

Thanks Guys for the ideas!!!
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Garcia5
General 1967-2002 F-Body Tech
15
Jul 7, 2022 06:51 PM
calaban
LT1 Based Engine Tech
18
May 18, 2020 06:43 PM
dbusch22
Forced Induction
6
Oct 31, 2016 11:09 AM
edxiel
LT1 Based Engine Tech
10
Jan 24, 2015 07:40 PM
dbusch22
LT1 Based Engine Tech
2
Jan 5, 2015 07:14 PM




All times are GMT -5. The time now is 11:17 AM.