What would cause the following timing problems? And how can I fix them?

Question

I reset my truck's timing by finding TDC of the compression stroke of cylinder 1 by following the instructions of a GM tech on Yahoo answers. By following his instructions I was able to start my engine easier (it barely cranks before starting) and my engine runs smoother. However, when I put a timing light to it, it shows Cylinder 1 as firing a whole second before the line hits TDC. I made sure with a piece of yarn that the V matched up with the TDC mark. But I figured I may have made a mistake, so I moved the harmonic balancer's mark in line with the V on the timing plate cover again and I took off the cap of the distributor and it was 180 degrees off. It was pointing towards terminal 5 instead of terminal 1 like it was suppose to. So I figured I made a mistake, aligned the rotor back with one, put everything back together and it started fine and ran smoothly, but it still fired 1 second before the line hit the V. I took it apart and it was 180 out again.

This problem keeps cropping up, I've tried to fix it over 4 times already. I normally wouldn't care except it's causing me to have an OBDII code for multiple/random cylinder misfire and cylinder 4 misfire. Any ideas?

My truck is a 98 Chevrolet S10 V6 4.3L with Enhanced Distributor Ignition and Central Sequential Fuel Injectors. It's the also Vortec model.

Answer 1

You can't check the timing with a lite. The computer senses the position of the piston and camshaft and decides timing by engine load, temperature, rpm, gear selected etc. There is no way to adjust timing. It is normal for the TDC mark to be far off when the engine is running.

The TDC mark goes by twice (the crank turns twice) while the distributor turns once so it's normal for the rotor to point 180 out every other revolution of the crank.

BTW it doesn't have a timing belt and you don't set the timing by moving the distributor. There is no timing adjustment.

Answer 2

Check that you have all the wires in the right firing order. The cars computer will advance or retard the timing. The timing should be before TDC on the timing mark. You may want to check the plug wires themselves, they might be bad. Good luck.

Answer 3

Most cars are set to fire just slightly....7 to 12 degrees...before top dead center. This allows the fuel mixture to have a more comlete burn ensuring full power to the compression stroke. If you truck is running, the timing is not 180 degrees out. You are looking at the top of the exhaust stroke.

Answer 4

Stop trying because it's fine.
The spark must fire early so the gas/air mixture will explode right at TDC.
Timing is usually expressed in degrees before TDC.
Leave it alone.

Answer 5

well you never set the timing by moving the harmonic balancer you always setthe timing by the dist.it sound like the timing belt is worn worn out if it still goes 180 out you need to take the car in and have the timing belt replace and then they will time the whole engine to the manufactory spec.