Timing question

[sebas54]

4.3l merc. I/O
If the timing isn't set will this cause the engine to not start?

I removed the distributor and I am not 100% certain that I installed it at TDC. How can I install the distributor at TDC without any help, by myself.


Thank you

 

[bill70]

Re: Timing question

If you don't have a timing gun you take the number one cylinder spark plug out and look Inside side with a flashlight while turning the motor over with a wrench until the piston is all the way up. Then set the distributor one the number one wire. This will get the timing very close then you can use a gun to make it better. It's much easier with two people though.

 

[searay3]

Re: Timing question

Have you resolved your fuel pump problem? Anyway to the question at hand...start by pulling #1 spark plug. With your thumb over the hole, rotate the engine by hand until you feel air move your thumb off the hole. Thats TDC, both valves closed, piston at the top of th stroke. go to the harmonic balancer and see that the timing marks are showing TDC. Go to the distributer, the rotor should be pointing at the wire that goes to number 1 cyl. with the cap in place. If it does not, lift the distributer and rotate and drop it in so it does. remember that if you rotate the distributor the oil pump drive will not line up. Simply take a long screwdriver and rotate the oil pump drive until you can once again lower the distrib completely. You can look down the hole with a light and see it. Start motor and following the manual, set the timing with the light.

 

[sebas54]

Re: Timing question

Thanks Searay!!

Can this be done manually, turning the engine and feeling for TDC? I have noone to help turn the engine and the two terminals are too far to crank it while my finger is on #1 spark plug hole.

I think I exaggerated with the fuel line swelling. All the fuel lines are A1 fuel lines. I reinstalled everything and it seems to be working and the fuel line are not under a lot of pressure. I think the reason it's not starting is because of timing. I thought that the timing was set but probably lost it on the install. That is my next step in trying to start the engine. If that does not work I will look back at the carb or have a pressure test for the intake manifold.

Thank you

 

[bhammer]

Re: Timing question

Yes, you need to do it the manual way so that you know you are at TDC. Just put a ratchet & socket on the harmonic balancer and turn it until your finger is pushed off. Then you can use a flashlight to get the piston exactly at TDC.​

 

[sebas54]

Re: Timing question

Thanks to everyone here i got the engine to start.

The engine back fired through the carb?? If I am 180 degrees off would the engine start?

I felt the air push through spark plug hole #1. This can only be felt on the compression stroke? Right?

 

[Don S]

Re: Timing question

Once you start feeling the compression build, you have to continue turning the crankshaft till the timing marks line up.
Then you install the distributor with the rotor pointing to #1 spark plug wire on the cap.
You are now in the general vacinity. You may have to turn the distributor back and forth a bit to get it started, once started, you will need to use the timing light to get to the right timing mark, You also have to be at idle rpm to set the timing, so set the timing, adjust idle, reset timing and idle as needed..

 

[sebas54]

Re: Timing question

After I felt the compressed air I continued till the mark lined up to 0. If I didn't get it on the compression stoke would I still feel air? And would the engine still start?

When it start it will stall and back fire????

 

[Don S]

Re: Timing question

Once you start feeling the compression build, you have to continue turning the crankshaft till the timing marks line up.
Then you install the distributor with the rotor pointing to #1 spark plug wire on the cap.
You are now in the general vacinity. You may have to turn the distributor back and forth a bit to get it started, once started, you will need to use the timing light to get to the right timing mark, You also have to be at idle rpm to set the timing, so set the timing, adjust idle, reset timing and idle as needed..

You haven't got it close enough to run right yet. It will take some trial and error to get it running enough to set with the light.

 

[sebas54]

Re: Timing question

Thanks Don, I got her running by turning the dist.

I was adjusting it when you told me, just a half inch at a time, now this time I turned it about 1/3 and she started right up. Thanks again to all!!!

I will time the egine with the gun once it get darker out


Thanks.

 

[sebas54]

Re: Timing question

I would just like to say thak you to everybody on this forum for giving me the encouragment and know how, to do these types of projects. Without forums like this one I would be at a total loss and unable to do what I need.

So, thank you all for a job well done!!!

 

[bhammer]

Re: Timing question

And thank you for posting back the result. It is always nice when an issue gets closed out.