72 will not start (1 Viewer)

[landcruiserluke]

My 72 fj40 will not start. It did start when taken out of winter storage. Actually problem started last fall before storage. Although when started did not run on all cylinders. Would run fine after revving engine. And would start fine while
starting and stopping on trip. Next couple of times starting cold engine same thing. Always ran fine after rough starting . Now it will not start. Sounds like it is firing. I changed points , coil and rotor. Set points to 18ths. Same problem will not start. Have new plug wires and distributor on order. Any other suggestions ?

 

[45Dougal]

How do the plugs look?
Gap set correctly, and producing a nice strong spark (not arcing along carbon deposits etc).

How about the resistor on the coil and the bypass connection to the starter?

 

[WildernessRimFab]

It could be lots of things, start with the easiest/cheapest that you can diagnose easily.
1. How old is the gas?
2. Have you checked your timing with a timing light on the flywheel?

 

[B y r o n]

It always boils down to air, fuel, and ignition. Find out which one is missing and it will run again!

 

[charliemeyer007]

Use your swiss army knife to scrape the aluminum contacts inside the distributor cap (I like the NAPA one with brass contacts). Is your gas fresh? Here there is summer and winter gas. Winter gas will vapor lock in summer heat. Summer gas doesn't want to vaporize in the cold. What about timing? I have a delco dizzy straight mechanical advance - in the summer I can jack the timing way up, winter its on the t mark. Good spark plug wires are worth the cost IMHO. Open the hood in the dark and look at the motor for fire around the wires.

 

[ToyotaMatt]

My 72 fj40 will not start. It did start when taken out of winter storage. Actually problem started last fall before storage. Although when started did not run on all cylinders. Would run fine after revving engine. And would start fine while
starting and stopping on trip. Next couple of times starting cold engine same thing. Always ran fine after rough starting . Now it will not start. Sounds like it is firing. I changed points , coil and rotor. Set points to 18ths. Same problem will not start. Have new plug wires and distributor on order. Any other suggestions ?

i can bet all the coins this topic is at play over a BAD PART ?

- parts wear over time and use , gas wears out over weeks

its real and so is Fayes Rock science

;;

 

[Muskyfever]

Could it be a faulty fuel pump?

 

[landcruiserluke]

Could it be a faulty fuel pump?

I see fuel in the sight window. It will not even fire up with starting fluid in carb. May spitter and sputter a little.

 

[45Dougal]

Fuel - check
Air - ?
Spark - ?

 

[Chungas Revenge]

Fuel - check
Air - ?
Spark - ?

The Holy Trinity of the internal combustion engine…

 

[diesellibrarian]

Air, fuel, spark...and compression. Have you checked timing? If your timing is off, spark might be happening when there's no compression, i.e. a valve is open.

 

[landcruiserluke]

Finally have the cruiser running. Went back to what I checked originally. Spark plugs. I have a tool to check spark was fine.
I have new wires coming and said I will change plugs to ngk platinum. Plugs only had 5k miles on them. Put new ones in and fired right up. Sometimes we over think things. At least I now know how to do points.. which were pitted. I will now put on new plug wires dist cap should be good to go.

 

[45Dougal]

Great to hear its running.
Runs with perfect new plugs, but not with 5k plugs.
Problem is probably not only the plugs but a weakening chain of other elements in the ignition.
Maybe time for a transition to electronic ignition?

 

[charliemeyer007]

Back in my aviation days we had a spark plug breakdown tester. Even new plugs you could blow out the spark at like 60 psi - Use a swiss pattern file and square edge the center electrode and properly set the gap that same plug would still have fire at 150 psi.

Take a broken hack saw blade, grind off the teeth, then thin down one end so it has about a 3/4" long skinny finger - make the best scraper tool for de-gunking the recess around the center electrode.