1989 Corvette Timing Gears
Thread Starter
Heel & Toe
Joined: Aug 2018
Posts: 17
Likes: 0
1989 Corvette Timing Gears
Here is my problem, on my L98 motor I am having timing issues. I pulled the wire to the ECM, start the car, set my timing to 6 BTDC. Lock down the distributor, re check timing at 6 BTDC. I then go and remove the battery cables for one minute, put the terminals back on the battery, plug in the EMC wire that is located by the brake booster. Start the car and try to keep it running, it wants to die. The car will not RUN well when the timing is 6 BTDC. If I move it back to 14 BTDC it runs good. Take it out and it pings big time, I understand why it is pinging. The car will accelerate ok, it does not miss at all. Accelerate it to 65-70, yes it pings while throttling up, gets to 70 and it purrs like a kitten. It has been suggested that it has jumped a tooth in the timing chain and gears. I recently purchased the car, so I have no real background on it. The car has 193,000 on it and the engine looks as if it has never been worked on, other than new plug wires, plugs, roter, and cap. Any help would be appreciated. Thanks.
Last edited by D Maners; Aug 14, 2019 at 08:35 PM.
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
Unlikely jumping a tooth. Engine has roller cam and doesn't use nylon timing gear. Chain will rattle loudly if stretched enough to jump a tooth. Reset timing to 15 at idle with everything connected. Drive car see how it does if no spark knock add 2 degrees at a time until you hear knock them back off 2 degrees. IDK what's up with your "set timing" procedure,. When " set timing" connector is disconnected : EST code will set snd ses light should be on. Reading previous thread timing was not a problem prior to adjusting it. Did you correct misfire? Carbon build up in EGR passages can cause spark knock.
