Help with timing problems needed
Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 5,941
Likes: 281
From: Was New Orleans but swam to Baton Rouge LA
Cruise-In IX Veteran
Help with timing problems needed
In the search to find out the reason why my car is backfiring I found my timing is off. I set the timing last week at around 10 degrees BTDC. Now this week I cannot even read the timing mark. It appears that the balancer spun 180 degrees. Is this possible?? When I was setting the timing last week I could not get it steady. The timing mark was jumping about 4 degrees each way. I plan on checking the balancer tommorrow, but would like to know what to look for to see if it is shot. My car appears to be running good it is just rough and backfires when attempting to start it. All help is appreciated.
Mark B.
Mark B.
Burning Brakes
Joined: Apr 2001
Posts: 752
Likes: 1
From: Springfield Oregon
Re: Help with timing problems needed (Sigforty)
Did you go through all the usual steps when you set your timing? Vacuum advance (if you have it) disconnected and vacuum port plugged? Are you sure you had the pickup on the right plug wire? I know these are kind of dumb questions, but it's the dumb stuff that always gets me. All this being right, is it possible you have an advance weight doing something wierd in your distributor? Maybe a spring came off one or something like that. You made need to go through the procedure of rolling your #1 cylinder around to TDC, coresponding with the rotor being in position to fire #1, and check that your balancer mark is where it should be in relationship to this. Best of luck.
Safety Car
Joined: Feb 1999
Posts: 3,631
Likes: 14
From: Fountain Hills AZ
Re: Help with timing problems needed (Sigforty)
"When I was setting the timing last week I could not get it steady. The timing mark was jumping about 4 degrees each way."
My first suspect would be a sloppy (or slipped) timing chain. It's also possible that there's another problem in addition to a bad timing chain.
My first suspect would be a sloppy (or slipped) timing chain. It's also possible that there's another problem in addition to a bad timing chain.
Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 5,941
Likes: 281
From: Was New Orleans but swam to Baton Rouge LA
Cruise-In IX Veteran
Re: Help with timing problems needed (ORVette)
I went through last week and replaced most of the things in the distributor. I checked and regapped all my plugs along with a new cap and rotor for the distributor. I had the timing light and all connected correctly. The first thing that popped in my head was the balancer being on its way out last week and spun this week causing the variance in timing. When I checked the timing I used my adjustable light that goes from 0-60 degrees advanced and i could not get the balancer mark anywhere close to timing tab. Tommorrow i plan on playing with it more. The motor seems to be running fine it just vibrates and occassionally backfires.
Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 5,941
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From: Was New Orleans but swam to Baton Rouge LA
Cruise-In IX Veteran
Re: Help with timing problems needed (Sigforty)
I am in the process of pulling everything off the front of the motor. There seems to be a problem removing the pulley from the balancer. Does anyone know if the balancer and pulley get removed together or separately?? I figure i will start with the balancer and if it looks good move on to the timing chain.
Mark B.
Mark B.
Le Mans Master
Joined: Sep 2000
Posts: 5,635
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From: Orlando Floriduh
Re: Help with timing problems needed (Sigforty)
There is a bolt in the center of the dampener. Take the pulley off first, then remove the center bolt and bolt a good puller to the dampener. It is not always easy to get them off but it is IMPOSSIBLE if you do not take the center bolt out. :lol:
Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 5,941
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From: Was New Orleans but swam to Baton Rouge LA
Cruise-In IX Veteran
Re: Help with timing problems needed (silvervetteman)
I have the center bolt and the other bolts removed, but the pulley does not want to come off of the balancer. I am just trying to figure out if I should attempt to pull them both at the same time now.
Mark B.
Mark B.
Le Mans Master
Joined: Sep 2000
Posts: 5,635
Likes: 4
From: Orlando Floriduh
Re: Help with timing problems needed (Sigforty)
I have seen some that were really tough to seperate for some reason. I think maybe you could rig something to pull everything as a unit. I did one car that had some sort of loc-tite on the dampener. Real tough.... :smash: :smash: :smash: :mad :smash:
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Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 5,941
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From: Was New Orleans but swam to Baton Rouge LA
Cruise-In IX Veteran
Re: Help with timing problems needed (silvervetteman)
Is there any thing i should mark. I put the distributor rotor on #1 cylinder, but my balancer is way off. I think it is either my balancer spun or the timing chain skipped a tooth. What should i go off of to detemine the problem and make sure the balancer gets back on correctly?
Mark B.
Mark B.
Le Mans Master
Joined: Sep 2000
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From: Westfield Indiana
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Re: Help with timing problems needed (Sigforty)
A couple of things come to mind. When you "put the rotor on number 1", is that where it was to begin with? Did you rotate the engine to get it to number 1? Or just bolt the rotor back on at number 1? I never tried to see if mine would go on "incorrectly" but it's a thought.
Also, when you replaced the rotor, it's possible that the weights bound up on each other. Mine did that and the mechanical timing wouldn't advance, causing backfires. Vac advance still worked though.
I know it's a bit late since you have the front of the engine apart, but thought I'd throw these your way, just in case.
[Modified by sharklover, 1:48 PM 3/30/2002]
Also, when you replaced the rotor, it's possible that the weights bound up on each other. Mine did that and the mechanical timing wouldn't advance, causing backfires. Vac advance still worked though.
I know it's a bit late since you have the front of the engine apart, but thought I'd throw these your way, just in case.
[Modified by sharklover, 1:48 PM 3/30/2002]
Melting Slicks
Joined: Dec 2000
Posts: 3,407
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From: Carmichael CA
Re: Help with timing problems needed (Sigforty)
Is there any thing i should mark. I put the distributor rotor on #1 cylinder, but my balancer is way off. I think it is either my balancer spun or the timing chain skipped a tooth. What should i go off of to detemine the problem and make sure the balancer gets back on correctly?
Mark B.
Mark B.
As for timing jumping around 4degrees mine did that and was due to slop in the distributor gear which is machined into the cam shaft...my only alternative is a new cam shaft...you might want to check that while you are messing with timing.
Keep us posted.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
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From: Unreconstructed, South Carolina
Re: Help with timing problems needed (Sigforty)
Sounds like the balancer may've slipped. I have a 71 L48 with keyed crank that I pulled the balancer from. My pulley was "stuck" to the balancer also. My engine appeared to have never been into, but I won't swear to that. Anyway, the pulley was actually sealed to the balancer with what looks like hot melt glue (??) ... same goo was also in the keyway of the balancer ... maybe to prevent oil leakage through keyway? Anyway, you can use your balancer puller tool with the pulley still attached to balancer ... just push puller bolts through the pulley holes & screw into the balancer. Separate the pulley on the bench. When you do, let me know how you did it ... I've not pried mine off yet. I do have a new balancer. Do use a balancer install tool to put new balancer back on so you don't risk damaging it. Some guys pound on it to get it on ... don't do it ... use the proper install tool. You can get a new balancer from your local parts store or Chevy dealer.
Thread Starter
Le Mans Master
Joined: Apr 2001
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From: Was New Orleans but swam to Baton Rouge LA
Cruise-In IX Veteran
Re: Help with timing problems needed (jackson)
Sharklover- The rotor is on correctly. There is only one way for it to go on. One side has a round dowel and the other a square dowel that seat into the weights on the distributor.
Rockn-Roll- I check the key after I removed the balancer and it is all right. I think the rubber in between the inertia wheel and the outer wheel slipped. I think this happened over the timing chain skipping due to the fact my car still ran great. I just needed to retune the carb since the weather changed.
Jackson- I removed the balancer and the pulley as a unit like you described. Then I set them on a bench and pryed the pulley off by wedging a screwdriver in between them. The pulley actually has a rolled lip inside that seats about 1/8 inch into the balancer's center. Now I just need to see another balancers timing groove in comparison to the key so I can definately know might moved.
Mark B.
Rockn-Roll- I check the key after I removed the balancer and it is all right. I think the rubber in between the inertia wheel and the outer wheel slipped. I think this happened over the timing chain skipping due to the fact my car still ran great. I just needed to retune the carb since the weather changed.
Jackson- I removed the balancer and the pulley as a unit like you described. Then I set them on a bench and pryed the pulley off by wedging a screwdriver in between them. The pulley actually has a rolled lip inside that seats about 1/8 inch into the balancer's center. Now I just need to see another balancers timing groove in comparison to the key so I can definately know might moved.
Mark B.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
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From: Unreconstructed, South Carolina
Re: Help with timing problems needed (Sigforty)
Mark:
When looking at face of balancer ... with centerline of keyway at 12 oclock position ... the timing mark should be approx ten (10) degrees to LEFT of centerline of keyway ... as in 10 degrees advanced from the keyway. I just looked at a brand new balancer, never installed. I don't have a degree wheel with me here ... but I recall it's 10 degrees.
When looking at face of balancer ... with centerline of keyway at 12 oclock position ... the timing mark should be approx ten (10) degrees to LEFT of centerline of keyway ... as in 10 degrees advanced from the keyway. I just looked at a brand new balancer, never installed. I don't have a degree wheel with me here ... but I recall it's 10 degrees.
Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 5,941
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From: Was New Orleans but swam to Baton Rouge LA
Cruise-In IX Veteran
Re: Help with timing problems needed (jackson)
My timing mark is to the left of the keyway like you said. I am not sure about 10 degrees, but it is about even with the edge of the center star leg above the keyway. Is that about 10 degrees or so??
Mark B.
Mark B.
Racer
Joined: May 2001
Posts: 401
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From: Carlsbad CA
Re: Help with timing problems needed (Sigforty)
Just a thought on the timing mark bouncing around like it is:
I had the same problem one day, and later the same day it had gone away. The second time I hooked the inductive pickup to the #1 wire up by the distributor, not down by the spark plug boot (I burned my finger on the header one too many times). I decided to see if I was getting some interference or arcing between spark plug wires, and sure enough, when I moved the pickup back down to the boot, the jump happened again. I am in the process of pulling my wires out of the "shields" under the headers and routing them separately like I have seen everyone on the forum do. Hope this helps. Sounds like you're on your way to getting the balancer problem fixed.
Good luck :cheers:
I had the same problem one day, and later the same day it had gone away. The second time I hooked the inductive pickup to the #1 wire up by the distributor, not down by the spark plug boot (I burned my finger on the header one too many times). I decided to see if I was getting some interference or arcing between spark plug wires, and sure enough, when I moved the pickup back down to the boot, the jump happened again. I am in the process of pulling my wires out of the "shields" under the headers and routing them separately like I have seen everyone on the forum do. Hope this helps. Sounds like you're on your way to getting the balancer problem fixed.
Good luck :cheers:
Drifting
Joined: Aug 1999
Posts: 1,468
Likes: 1
From: Kirkland WA
Re: Help with timing problems needed (thebruce)
Thebruce makes a good point.
If the pickup on your timing light is too close to another wire it will cause skipping. When I check my timing, I always do it near the distributor. I have QUITE a bit of slack in my #1 wire, so I can pull it a good 3-4 inches away from the other wires.
Also, I wouldn't discount worn bushings in the distributor. I had a bouncing timing mark until I sent the whole thing off to Lars for a rebuild.
If the pickup on your timing light is too close to another wire it will cause skipping. When I check my timing, I always do it near the distributor. I have QUITE a bit of slack in my #1 wire, so I can pull it a good 3-4 inches away from the other wires.
Also, I wouldn't discount worn bushings in the distributor. I had a bouncing timing mark until I sent the whole thing off to Lars for a rebuild.
Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 5,941
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From: Was New Orleans but swam to Baton Rouge LA
Cruise-In IX Veteran
Re: Help with timing problems needed (Corellian Corvette)
Well I have gotten the balancer off, but it does not appear to be the problem. It looks like there is something wrong with the timing chain. I think I am going to have to wait till next week though to pull the oil pan and timing cover to see for sure. The balancer would not align with the 0 timing mark or anywhere close when I had the distributor and rotor on #1 plug wire. Can anyone recommend any timing chain sets? Although distributor slop could be adding to the problem I do think there is something greater. Does anyone have any info for when I pull the timing cover?
Mark B.
Mark B.
