Will an 80 start if Rotor is off 180 degrees? (1 Viewer)

[Fitzer]

I went ahead and did the distributor o-ring job and all went well until it didnt start after finishing the job. I did notice I couldnt get the rotor to point to the 11 o'clock on reassemble....it wanted to end up at 11:30 but was still pointing to wire #1. After several tries and no starts I set the flywheel to TDC Zero and the rotor pointing to 5 o'clock, pulled it and lined up the notches put it back in and it pointed to 11 o'clock and it started. I thought for sure it was pointing to 11 o'clock when I first disassembled....maybe not. But will an 80 start/run if the rotor is off 180 degrees?.....is it firing one cylinder ahead in timing? It feels like it is running fine.... I just want to make sure I'm not doing damage long term. Hopefully I just had a " moment" when I first disassembled and should have cranked it to zero one more time and hope that someone knows that it will not run if set 180 degrees off.

 

[mattafact]

I had the same problem when I did mine and it wouldn't start unless it was right on.

 

[sdnative]

Was it TDC on the compression stroke or exhaust stroke? I would have to think about what would happen if you were on the exhaust stroke and the rotor was 180 out

Are the wires ordered correctly?

 

[Fitzer]

I don't know if it was compression or exhaust. The wires should be in correct order...I did not unplug them from the cap or at the plugs. It is possible that I pulled the distributor/rotor out at 5 o'clock and reassembled at 11 o'clock the first time and hence the no starting. Pulling a 2nd time from 5 o'clock and reassembled at 11 o'clock and then it starts and appears to run fine might have set it back straight. If it starts and appears to run fine 180 degrees off, but can lead to long-term issues, I would like to know before I damage something. When I did it the first time to change the o-ring I only to cranked the fly wheel to TDC zero one time, pulled the cap and thought "good, I got lucky and don't have to wrench it around one more time" as I thought the rotor tip was pointing to 11 o'cock.

 

[jonheld]

I would have to think about what would happen if you were on the exhaust stroke and the rotor was 180 out

Nothing. There can't be fire without compression+fuel+air. This stuff only works one way.

 

[Pin_Head]

It won't run 180 degrees out. The easy way to fix it is to swap plug wires on opposite sides of the distributor (eg. 1 & 6, etc.) without pulling and reinstalling the distributor. It accomplishes the same thing.

 

[Fitzer]

If it won't run 180 degrees off, then I must have had a a dumb moment when I first disassembled and thought the opposite of what I actually saw. The only other possibility is if there is any internal gearing inside the dristributor that threw it off as I know the rotor spun around probably forwards and backwards while it was out while I was holding/cleaning the unit. Can any other gurus confirm that it wouldn't run 180 degrees off and that I should be ready to wheel. When I did get it started, it RPM'd at 1900 for a few minutes. I turned off and re-started and it idled fine around the 750 mark. I kdon't know if that is common as the ECU/timing is re-calibrating.

 

[jonheld]

If the motor is running well, then the motor is running well. I'm not sure what else you're looking for here.
It is mechanically impossible for the motor to run with the dissy rotor 180 out. Think about what's happening inside the combustion chamber when the spark ignites. There would be no fuel, air, or compression because the spark is igniting on the top of the exhaust stroke. There's nothing in there to ignite. In fact the motor would struggle to run if your ignition timing was more than 10 degrees out.

 

[sdnative]

Check the ordering of the plug wires on the cap and trace them to the spark plugs. They should follow the firing order of the motor in the direction the rotor spins. Also, put a timing light on it. If everything checks out, don't worry about it.