timing varies....
Thread Starter
Race Director
Joined: Apr 2003
Posts: 19,347
Likes: 654
From: Tampa, Florida
timing varies....
My timimg is set to 8 degrees initial with a digital timimg light. I change the timing light to 36 degrees to check mechanical advance and rev it slowly. The timing mark on the balancer is all over the place in relation to the tab. It will go from very advanced to retarded and back to advanced and all over. Its bouncing all over the place.
Right now I can only think of two things that will cause this:
1. Misfire
2. I'm not steady with the throttle and as the RPM varies the mechanical weights are opening and closing. The only problem with this theory is the timing mark should never cross '0' but it does.
BTW...I set the points with a feeler gauge and my dwell reads 43. I cant get the dwell within range.
Thanks,
Jim
Right now I can only think of two things that will cause this:
1. Misfire
2. I'm not steady with the throttle and as the RPM varies the mechanical weights are opening and closing. The only problem with this theory is the timing mark should never cross '0' but it does.
BTW...I set the points with a feeler gauge and my dwell reads 43. I cant get the dwell within range.
Thanks,
Jim
Race Director
Joined: Jul 2004
Posts: 12,696
Likes: 329
From: Scottsdale Arizona
Are you sure that the balancer isn't the cause? For the longest time I thought that my problem was with the distributor but then pulled off the old harmonic damper and found that the rubber had completely rotted away. The outer ring was almost spinning free.
Thread Starter
Race Director
Joined: Apr 2003
Posts: 19,347
Likes: 654
From: Tampa, Florida
Racer
Joined: Jul 2003
Posts: 455
Likes: 0
From: Buffalo New York
first make sure that the timing light is only on the #1 plug wire or cap of the distributor and that is not touching any other plug wire or terminal on the cap. If it does it will read from both and it will bounce all over the place.
If that is not the issue then see the other posts so far (i.e. distributor)..
Good luck
Chris
If that is not the issue then see the other posts so far (i.e. distributor)..
Good luck
Chris
Melting Slicks
Joined: Mar 2004
Posts: 3,472
Likes: 18
From: Lake Ozark, MO
Make sure the plug wire is good... switch to another wire and see if the flash is steady (of course you can't take a reading like that) if it is you have a bad wire / plug. You may have a bad pickup on the light. After that it becomes mechanical.
Tech Contributor
Joined: Aug 1999
Posts: 14,374
Likes: 6,373
From: At my Bar drinking and wrenching in Lafayette Colorado
You gotta' fix this before you try setting the timing. Why can't you get the dwell in range - will the screw not turn..? You have to get 30-31 degrees dwell before ever attempting to set timing.
Thread Starter
Race Director
Joined: Apr 2003
Posts: 19,347
Likes: 654
From: Tampa, Florida
Lars, when I turn on the meter it reads 45. After grounding it and touching the negative coil post it reads 43-ish. The screw turns (the point gap changes as well, verified with cap off) but the dwell reading doesnt change as I turn it.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Thread Starter
Race Director
Joined: Apr 2003
Posts: 19,347
Likes: 654
From: Tampa, Florida
first make sure that the timing light is only on the #1 plug wire or cap of the distributor and that is not touching any other plug wire or terminal on the cap. If it does it will read from both and it will bounce all over the place.
If that is not the issue then see the other posts so far (i.e. distributor)..
Good luck
Chris
If that is not the issue then see the other posts so far (i.e. distributor)..
Good luck
Chris
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
If that doesn't fix your problem, you might suspect the timing light being defective....especially if the engine doesn't sound all that bad. If Timing was jumping around as much as you indicate, it should be running really rough. Borrow a light from a neighbor/friend and see what it shows.
Thread Starter
Race Director
Joined: Apr 2003
Posts: 19,347
Likes: 654
From: Tampa, Florida
If that doesn't fix your problem, you might suspect the timing light being defective....especially if the engine doesn't sound all that bad. If Timing was jumping around as much as you indicate, it should be running really rough. Borrow a light from a neighbor/friend and see what it shows.
It runs rough. My distributor endplay is .045. Time to order some shims.
Tech Contributor
Joined: Aug 1999
Posts: 14,374
Likes: 6,373
From: At my Bar drinking and wrenching in Lafayette Colorado
Then your meter has an internal; ground and is no good. Set the point gap to .016" when wide open and let it go - this will produce just about 30 degrees of dwell. Once set, re-verify timing since a change in dwell produces an equal change in timing.
