Ok, so I've been trying to get my 78 f150 running. I can not get my 300 timed to save my life. I've set the number one cylinder to top dead center on the compression stroke. I set the distributor with the rotor facing the correct way and I've even adjusted the distributor almost all the way around slowly while trying to crank it. I cannot figure out why it will not crank to save my life. Please help!

 

Is your rotor spinning while cranking ? Do you have proper Spark ?

 

Yes, the rotor is definitely spinning. And I am getting a very good spark. I did only check the number one cylinder for this though. But my approach was correct right?

 

Yes . TDC #1 on compression . Rotor pointing to #1on cap . Should get you in the ball park . Timing marks could be off and not usable . Fire and fuel under compression at the proper time , It should at least try to run . What led to your current no run condition . Did it just die ? or has it been sitting a while ?

 

How did you check for compression stroke?

I like pulling #1 spark plug and feeling for air being pushed out...

Also, The 300 timing cover has several timing marks, are you looking at the right ones?

 

It was running fine. Then I was pulling some bushes out for my neighbor and it just all of a sudden started running like crap. I thought it was the carb because I didn't mess with the timing at all. I tried my friends carb on it and it didn't help at all. So I figured maybe something happened with the timing so I tried to adjust the distributor and noticed that it wasn't getting better. So that's when I decided to try and reset the timing by finding top dead center. I find it by having my friend hold his finger over the hole until it blows out then put a dowel in the hole and turn it until the dowel stops moving up. I have done a compression test on the truck and all of my readings were good. I just don't know what could have happened.

 

I think you need to start from square one . Timing does not go off all at once unless something broke . Stripped gears in the timing or at the dizzy .

 

I have replaced the dizzy. And check the gears each time I've pulled it and they seem fine. I've reset it to top dead center 3 or 4 times now. I dont really know how much further I can go back to start at the beginning. I did make sure there was fuel and spark.

 

Good spark ? week coil ? Bad module ? Have it tested . Fuel quality ? I towed one in a few weeks ago . Had half a tank of water in it .... Just saying . you are focused on timing . It may be something else .

 

One more thing ... I had one towed years ago. Guy backed into a dirt bank, plugged his exaust 8 inches deep with dirt and killed the engine .... Just saying take a breath ( that can help ) and look at other possibles . Best of luck !

 

Lol thanks, I have had to do that several times actually. That is probably the best thing to do I've also found out!

 

Once you fix the problem and get it to fire you can time it with a vacuum gauge quick and easy.

 

I usually do time with a vacuum gauge. I just have to get it to run...

 

You're getting a nice fat blue spark that snaps? A weak spark under compression, won't fire the charge.

 

Yes, the spark looks very clean and strong. I will put some more gas in there the next time I get a chance to get over there and work on it. I feel like the quality of the gas could be the only thing or the quantity of it. I just need to get this figured out!