New camshaft, timing problems
Thread Starter
Pro
Joined: Dec 2000
Posts: 560
Likes: 0
From: Camino CA
New camshaft, timing problems
In my 81, I put in the Crane Energizer Cam 272 H10 with new lifters, and I made certain that the timing marks on the timing gears were matched up, but I had to advance my timing to 27 degrees in order to get it to run. I have an automatic transmission and whenever I stop while it's in 3rd, like at a light, my check engine light comes on, when I give it a little gas it goes off, but what do I need to do to fix this? Here's the link to my camshaft card http://dab7.cranecams.com/SpecCard/D...1=Display+Card
Burning Brakes
Joined: Aug 2000
Posts: 852
Likes: 0
From: Katy TX
Re: New camshaft, timing problems (Ben Taylor)
27 degrees sounds like an awful lot. Are you sure the distributor is in correctly? I would try redropping the distributor rotating back 1 gear tooth on the shaft.
Edit;
Just checked a distributor gear and they have 13 teeth.
360/13 = 27.6
So if you are off one tooth you would be 27.6 degrees out. If this is true you are running at about 0 advance although your timing indicator on your balancer shows 27 degrees advance. If my logic is screwed someone please speak up. I have dropped distributors off a tooth before but figured out the problem before actually getting it to run and setting the timing.
[Modified by PatG, 6:07 PM 3/1/2002]
Edit;
Just checked a distributor gear and they have 13 teeth.
360/13 = 27.6
So if you are off one tooth you would be 27.6 degrees out. If this is true you are running at about 0 advance although your timing indicator on your balancer shows 27 degrees advance. If my logic is screwed someone please speak up. I have dropped distributors off a tooth before but figured out the problem before actually getting it to run and setting the timing.
[Modified by PatG, 6:07 PM 3/1/2002]
Drifting
Joined: Jan 2002
Posts: 1,645
Likes: 11
From: Schaumburg IL
Re: New camshaft, timing problems (Ben Taylor)
Right on PatG. One tooth is what you say and it easy to get one off. Bring the engine to TDC on #1 with the balancer at 0 degrees and see where the rotor is pointing. Should be right on the money to the #1 post in the cap. If is between posts, move it one tooth to line things up. Then try retiming it.
Thread Starter
Pro
Joined: Dec 2000
Posts: 560
Likes: 0
From: Camino CA
Re: New camshaft, timing problems (PatG)
I don't think that should change anything, if I do change what tooth it is on, the car won't start without me turning the cap, which would put the timing back at around 27 degrees advanced. The car seems to be running great, no pinging or anythin. I figured out that the check engine light is only coming on when the RPMs get to 600 or lower, with my old cam it idled at about 850.
Burning Brakes
Joined: Aug 2000
Posts: 852
Likes: 0
From: Katy TX
Re: New camshaft, timing problems (Ben Taylor)
"I don't think that should change anything, if I do change what tooth it is on, the car won't start without me turning the cap, which would put the timing back at around 27 degrees advanced"
One more area to look is at the balancer. If you are running a stock balancer the outer ring may have slipped. Did you note the timing with the old cam in the car? This would not explain the rough idle though.
Drifting
Joined: Oct 2000
Posts: 1,825
Likes: 56
From: Shawano WI
Re: New camshaft, timing problems (PatG)
Having the distributor off 1 tooth will not change the timing, you just have to rotate the distributor body to compensate for it. If the timing mark reads 27 degrees it is timed at 27 degrees regardless of the position of the distributor.
Balancers can and often do slip. Double check that TDC on the motor coresponds with the mark on the balancer.
Also check your timing light against someone elses. I have seen timing lights be off as much as 10 degrees.
Balancers can and often do slip. Double check that TDC on the motor coresponds with the mark on the balancer.
Also check your timing light against someone elses. I have seen timing lights be off as much as 10 degrees.
Drifting
Joined: Dec 1999
Posts: 1,541
Likes: 2
From: Raleigh NC
Re: New camshaft, timing problems (Pete79L82)
I am backing Pete on this one. You are timing by a light that is triggered by the voltage passing through the number one spark plug wire. You can adjust for a tooth off. Did you install the cam straight up?
Thread Starter
Pro
Joined: Dec 2000
Posts: 560
Likes: 0
From: Camino CA
Re: New camshaft, timing problems (Rob's 73)
I replaced the balancer about 5 months ago, so I don't think the outer ring has slipped, when I installed the camshaft I put it straight up, with the dots on the timing gears lined up, and when I put the timing cover and the balancer on, the timing mark lined up with TDC on the cover. I last checked my timing with the old camshaft when I replaced the harmonic balancer, and it was about 7 degrees advanced. The only other timing light I have access to is not adjustable, but the timing mark looks like it's at about the same spot as when I set the timing to 0 on mine. The car isn't idling rough, just at a low RPM.
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
Drifting
Joined: Oct 2000
Posts: 1,825
Likes: 56
From: Shawano WI
Re: New camshaft, timing problems (Ben Taylor)
In my 81, I put in the Crane Energizer Cam 272 H10 with new lifters, and I made certain that the timing marks on the timing gears were matched up, but I had to advance my timing to 27 degrees in order to get it to run.
Do computer controled cars have mechanical advance, that the weights could be stuck at full advance?
Thread Starter
Pro
Joined: Dec 2000
Posts: 560
Likes: 0
From: Camino CA
Re: New camshaft, timing problems (Pete79L82)
It wouldn't even start at the stock settings, if I only advance it to about 15 degrees it will start, then die if I let off the gas.
The advance is controlled by computer I believe, the advance is different at different RPMs, so it seems to be working, the 27 degrees was at about 770 RPM which is where it idles in park.
I was told at the store where I got the camshaft that this would work in my car without a problem, but after looking at the Crane Cams webpage this cam is for 57-87 cars without computers.
Excuse me while I go and push my car off some cliff, then report it stolen.
The advance is controlled by computer I believe, the advance is different at different RPMs, so it seems to be working, the 27 degrees was at about 770 RPM which is where it idles in park.
I was told at the store where I got the camshaft that this would work in my car without a problem, but after looking at the Crane Cams webpage this cam is for 57-87 cars without computers.
Excuse me while I go and push my car off some cliff, then report it stolen.
Racer
Joined: Dec 1999
Posts: 317
Likes: 0
From: olean ny usa
Re: New camshaft, timing problems (Ben Taylor)
any chance you have the timing light connected to cylinder number 2?
should be on the front cylinder on the driver's side.
throw the light out and time it by ear. trial and error until it starts well and runs well. then put the light on it and see what the timing is
should be on the front cylinder on the driver's side.
throw the light out and time it by ear. trial and error until it starts well and runs well. then put the light on it and see what the timing is
