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

2800 Rpm after timing belt change

Thread Tools
 
Search this Thread
 
Old 02-13-2009 | 05:24 PM
  #16  
Grey Wolf's Avatar
Grey Wolf
Racer
 
Joined: Aug 2008
Posts: 389
Likes: 0
From: Saxonburg, Pa.
Default

another question. When I got my 84S, we did a T/B job. I noticed that the timing marks on the cam gears were to the backside of the gear. However, I aslo noticed on another (same size engine) that the timing marks were towards the front of the cam gear. Also noticed was the fact that the timing marks weren't at the top of the tooth nor quite in the valley of the tooth either. If the cam gear is placed on backwards as to the way it came off, could this effect timing?
Old 02-13-2009 | 05:27 PM
  #17  
jon928se's Avatar
jon928se
Addict
Rennlist Member

 
Joined: Nov 2003
Posts: 2,608
Likes: 11
From: Sydney AUS
Default

Originally Posted by Tampa 928s
Let me get this clear one revolution of the crank and two on the cams. When I set the TDC I made sure the piston was at the top of its travel. I just checked with the crank at 0 the piston was all the way to the top the cam marks were not showing, around again and the piston was on the top and cams were lined up. Is there any way that this is incorrect and having the piston in the correct spot when I started?
TWO revolutions of the crank equals ONE revolution of the cams.

I think you know this but typed it wrong.
Old 02-13-2009 | 05:37 PM
  #18  
Tampa 928s's Avatar
Tampa 928s
Thread Starter
Race Car
 
Joined: Dec 2006
Posts: 4,089
Likes: 6
From: Tampa Florida
Default

Gray it has euro cams which puts it in the gray zone:

I got it running looks like the owner did not notice the Plenum had lifted off a little, I reseated it and it started. My distributor is at the end of its travel is there a procedure when you insert it in reference to that line?
Old 02-13-2009 | 05:40 PM
  #19  
dr bob's Avatar
dr bob
Chronic Tool Dropper
Lifetime Rennlist
Member
 
Joined: Oct 2001
Posts: 20,506
Likes: 549
From: Bend, Oregon
Default

One too-common thing to look for is the balancer on correctly. With the balancer on backwards, cam timing will always be wrong. Should be able to read the numbers right-side-up looking from the front.

Otherwise, you are correct on the way you determined #1 TDC. On the compression stroke, the rotor should point to the #1 plug wire. Hopefully, you didn't move the distributor much during your work. Distributor drives at the same speed as the cam, and the relationship should not change when you change a belt.


I want to throw out another possibility, and that is that you have a broken cam. On your 16V car it's relatively easy to pull the cam covers to check. Kind of remote chance but worth consideration if you don't find something else. You could quickly see symptoms of this with a very basic leakdown test, and also for sure with a compression test on all the cylinders.
Old 02-13-2009 | 06:32 PM
  #20  
Tampa 928s's Avatar
Tampa 928s
Thread Starter
Race Car
 
Joined: Dec 2006
Posts: 4,089
Likes: 6
From: Tampa Florida
Default

Got it seems like the timing was off I reinserted the distributor the rotor needs to be at the leading edge of the line toward the passenger side not the drivers side. It's running fine, I have a slave on the way and will drive it tomorrow and reset the timing.
Old 02-13-2009 | 07:59 PM
  #21  
dr bob's Avatar
dr bob
Chronic Tool Dropper
Lifetime Rennlist
Member
 
Joined: Oct 2001
Posts: 20,506
Likes: 549
From: Bend, Oregon
Default

Originally Posted by Tampa 928s
.... I have a slave on the way and will drive it tomorrow...

Need pictures of the slave. Could probably use one myself but not worth keeping one full-time.
Old 02-13-2009 | 08:03 PM
  #22  
Tampa 928s's Avatar
Tampa 928s
Thread Starter
Race Car
 
Joined: Dec 2006
Posts: 4,089
Likes: 6
From: Tampa Florida
Default

Dr. Bob is that a joke
Old 02-13-2009 | 10:21 PM
  #23  
Sailmed's Avatar
Sailmed
Three Wheelin'
 
Joined: Dec 2005
Posts: 1,822
Likes: 1
From: In the boatyard installing the mast and engine, we don't need a crane, we harness the mesquito's! Yeah!
Default

Mark...
obviously you have a destroyed engine...
just send the car to the farm and I promise to take good care of it...
better yet... the flat bed will be there at 9am tomorrow..
I'll let you know what happened
Old 02-13-2009 | 11:02 PM
  #24  
Tampa 928s's Avatar
Tampa 928s
Thread Starter
Race Car
 
Joined: Dec 2006
Posts: 4,089
Likes: 6
From: Tampa Florida
Default

Nice !



Quick Reply: 2800 Rpm after timing belt change



All times are GMT -3. The time now is 08:11 PM.