Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

Checking for timing jump

Thread Tools
 
Search this Thread
 
Old 06-26-2011, 09:37 PM
  #31  
Imo000
Captain Obvious
Super User
 
Imo000's Avatar
 
Join Date: Aug 2003
Location: Cambridge, Ontario, Canada
Posts: 22,846
Received 337 Likes on 244 Posts
Default

Evne if only one bank of valves are bent, might as well pull the other head to and put a new head gasket in there. It's not that much more work to pull the other head.
Old 06-26-2011, 09:51 PM
  #32  
Mrmerlin
Team Owner
 
Mrmerlin's Avatar
 
Join Date: May 2004
Location: Philly PA
Posts: 27,906
Received 2,257 Likes on 1,250 Posts
Default

turn it in what ever direction is shortest to ge the crank to the 45deg line.

NOTE at this point the cams dont really matter as they can be turned in either direction once the belt is off. once the crank is at 45 deg the cams can be turned full rotations.

NOTE the 45 degree mark on the cams will be about 3 teeth before the hash marks would line up with the cam housing
Old 06-26-2011, 10:06 PM
  #33  
Bill Ball
Under the Lift
Lifetime Rennlist
Member
 
Bill Ball's Avatar
 
Join Date: Mar 2002
Location: Buckeye, AZ
Posts: 18,647
Received 46 Likes on 33 Posts
Default

Go ahead with the teardown at 45 degrees. Back up to 45 BTDC- as little turning as possible, like Stan said.

You might have escaped unharmed. 7 cam teeth is not certain death. We lucked out on Jon's car when the WP seized and stripped a pile of belt teeth. BUT the way it is running/not running sounds like more than just timing way off.

If everything goes back togther (e.g., the cam is not snapped), we can do a leakdown (do I need to bring my compressor?) or a compression test. Actually a compression test is quicker and simpler and will tell us what we need to know.
Old 06-26-2011, 10:46 PM
  #34  
Hilton
Nordschleife Master
 
Hilton's Avatar
 
Join Date: Jun 2006
Location: ɹəpun uʍop 'ʎəupʎs
Posts: 6,279
Received 54 Likes on 44 Posts
Default

Originally Posted by Charley B
Never got a belt warning. I should have all the tools we need, Bill. Unless you have a reason for me to leave the pully's and belt at this stage, for anything you might want to check, I'll go ahead and finish the tear down.
Crossing fingers for you.

Belt warning is inop until 3 mins after startup - so if something broke when you started it, you have no idea until the bad sounds.
Old 06-26-2011, 10:51 PM
  #35  
Charley B
Rennlist Member
Thread Starter
 
Charley B's Avatar
 
Join Date: Apr 2006
Location: Patterson, Ca
Posts: 4,373
Likes: 0
Received 2 Likes on 2 Posts
Default

OK Bill. I have several air compressors and a good compression gauge so we're fine there.

Good point Hilton. I never had it running for three minutes once it began to run funny.
Old 06-27-2011, 02:01 AM
  #36  
Charley B
Rennlist Member
Thread Starter
 
Charley B's Avatar
 
Join Date: Apr 2006
Location: Patterson, Ca
Posts: 4,373
Likes: 0
Received 2 Likes on 2 Posts
Default

Who can tell me what this three hole female plug is? It comes from under the intake, joins the front loom with the belt warning wire and was laying down near the top of the air pump.
Attached Images  
Old 06-27-2011, 02:14 AM
  #37  
Mrmerlin
Team Owner
 
Mrmerlin's Avatar
 
Join Date: May 2004
Location: Philly PA
Posts: 27,906
Received 2,257 Likes on 1,250 Posts
Default

is the Hall sensor connected?
this is on the backside of the right cam tower behind the housing
Though i thought the Hall sensor had a 2 prong connector
Old 06-27-2011, 03:12 AM
  #38  
Charley B
Rennlist Member
Thread Starter
 
Charley B's Avatar
 
Join Date: Apr 2006
Location: Patterson, Ca
Posts: 4,373
Likes: 0
Received 2 Likes on 2 Posts
Default

I found this on Pirtles' site. This looks like the connector, down below the rotor, but I can't find the male end. I guess he's labeling it as a right fuel rail connection.
Attached Images  
Old 06-27-2011, 02:02 PM
  #39  
Bill Ball
Under the Lift
Lifetime Rennlist
Member
 
Bill Ball's Avatar
 
Join Date: Mar 2002
Location: Buckeye, AZ
Posts: 18,647
Received 46 Likes on 33 Posts
Default

That's the Hall sensor plug. The knock sensors and Hall are 3-wire, with the 3rd wire being the shielding. The sensor side of the connector fractures and the plug comes off and you lose 6 degrees of advance at higher RPM. More fun for Wednesday.
Old 06-27-2011, 04:24 PM
  #40  
Mrmerlin
Team Owner
 
Mrmerlin's Avatar
 
Join Date: May 2004
Location: Philly PA
Posts: 27,906
Received 2,257 Likes on 1,250 Posts
Default

so your car has been running without the Hall connected??

interesting you will have new found HP once you fix all the issues
Old 06-27-2011, 04:40 PM
  #41  
Charley B
Rennlist Member
Thread Starter
 
Charley B's Avatar
 
Join Date: Apr 2006
Location: Patterson, Ca
Posts: 4,373
Likes: 0
Received 2 Likes on 2 Posts
Default

Originally Posted by Mrmerlin
so your car has been running without the Hall connected??

interesting you will have new found HP once you fix all the issues
Holy Crap! It was already more than I could handle. I better start wearing a helmet.
Old 06-27-2011, 06:00 PM
  #42  
Charley B
Rennlist Member
Thread Starter
 
Charley B's Avatar
 
Join Date: Apr 2006
Location: Patterson, Ca
Posts: 4,373
Likes: 0
Received 2 Likes on 2 Posts
Default

I found the male end of the Hall sensor connector. It looks to be in very good shape other than the retainer clip being loose.
Attached Images  
Old 06-27-2011, 06:35 PM
  #43  
dr bob
Chronic Tool Dropper
Lifetime Rennlist
Member
 
dr bob's Avatar
 
Join Date: Oct 2001
Location: Bend, Oregon
Posts: 20,506
Received 545 Likes on 408 Posts
Default

Charley--

What's left of the connector looks fine. The missing part is still inside the part you have on the end of the harness. A small dentist's probe can be used to break up and extract the remnants stuck inside.

The Hall sensor lower bolt can be a real chore to get out. I used a long Allen driver on a couple extensions so the ratchet handle is back of the shock tower, makes it real easy vs the tight space and a conventional Allen key and arthritic fingers.. Put some stickum on the end of the driver so it hangs on to the little bolt, else it will wander off into the nether regions by the AC compressor and suspension/crossmember.

The replacement sensor (944 part) comes with a cable stub that's just a hair too short to go back in the bracket like the original. Loosen the cable clamp on the new one and you can get a little bit of extra wire length to play with to get the connector seated in the bracket again.
Old 06-27-2011, 06:47 PM
  #44  
Charley B
Rennlist Member
Thread Starter
 
Charley B's Avatar
 
Join Date: Apr 2006
Location: Patterson, Ca
Posts: 4,373
Likes: 0
Received 2 Likes on 2 Posts
Default

Originally Posted by dr bob
The missing part is still inside the part you have on the end of the harness.
The replacement sensor (944 part) comes with a cable stub that's just a hair too short to go back in the bracket like the original.
So I guess it's not an effective procedure to just push it back together again and secure it to the bracket.

Do you have the 944 part number?
Old 06-27-2011, 07:54 PM
  #45  
IcemanG17
Race Director
 
IcemanG17's Avatar
 
Join Date: Sep 2004
Location: Stockton, CA
Posts: 16,265
Received 71 Likes on 56 Posts
Default

great news.....I know when Sharky had a dead hall sender it was VERY noticeable in the "butt-o-meter"...huge really.....my cheapo dyno recorded it as 50whp....the GTS will really wake up with the extra 6' of timing....that plus the TB repair is gonna give you a completely NEW ride..... Congrats!!!!


Quick Reply: Checking for timing jump



All times are GMT -3. The time now is 01:09 AM.