FJ40 what did I break?? (2 Viewers)

[Jaws87]

Question for those more versed in F engines than I am. I was trying to get my 1973 started after a long restore. I finally got it to fire and was letting it run for 15 to 20 seconds at a time while I fine tuned it. Well, it seized up on me at one point. I discovered that my distributor was set on top of the bracket and not the block, so it probably was not turning the oil pump. I was able to turn it back and forth by hand and free it up, but now it will not start. I have verified spark, fuel and compression. I noticed that the fuel from the carb was just kind of pooling in the intake manifold and getting to the pistons. I checked and I have zero vacuum while cranking. I was thinking maybe when it froze I broke the timing gear? I'm completely out of ideas. Any help would be very much appreciated!

 

[cruisermatt]

if it actually seized it's done. Pull the motor, disassemble and asses. And probably start shopping for another long block.

 

[Jaws87]

if it actually seized it's done. Pull the motor, disassemble and asses. And probably start shopping for another long block.

I was doubtful it totally seized because I was only letting it run for 15 to 20 seconds at a time. It cranks freely and even stumbled a couple times like it wanted to start, but then nothing. It's not even attempting to fire. Would the starter still crank like normal if it's fried?

 

[cruisermatt]

If what you are saying is true, and it actually seized due to running with no oil pressure, then it's junk. No one can actually determine that for you through the internet though.

 

[Jaws87]

If what you are saying is true, and it actually seized due to running with no oil pressure, then it's junk. No one can actually determine that for you through the internet though.

You may very well be correct. I am just trying to make sure it's garbage before I go through the trouble of pulling this thing. Thank you for your quick replies!

 

[charliemeyer007]

I'd check your timing again, easy to get off a tooth are it rotates in. Look for damage on the dizzy drive gear. Maybe a bore scope to look at the other drive gear.

It can only take only seconds for un-lubricated parts rubbing together to be ruined.

In the future, when starting an engine after it was rebuilt or set for a long while - pull the plugs and spin the engine over until it builds oil pressure. I always put in a few cc's of Marvel's Mystery Oil in every jug, spin the engine a little to distribute the oil; when putting an IC engine to sleep.

 

[Rocky_LC]

Are you sure the timing is set correctly if the distributor was loose?

Can’t be sure about the engine’s status, as has been said.

You can drop the oil pan and inspect bearings & journals…

Pretty big job, but….

 

[Jaws87]

I'd check your timing again, easy to get off a tooth are it rotates in. Look for damage on the dizzy drive gear. Maybe a bore scope to look at the other drive gear.

It can only take only seconds for un-lubricated parts rubbing together to be ruined.

In the future, when starting an engine after it was rebuilt or set for a long while - pull the plugs and spin the engine over until it builds oil pressure. I always put in a few cc's of Marvel's Mystery Oil in every jug, spin the engine a little to distribute the oil; when putting an IC engine to sleep.

I will check timing again. Thanks for the tip on spinning the oil pump. I read that somewhere else and will not forget to do it in the future.

 

[Jaws87]

Are you sure the timing is set correctly if the distributor was loose?

Can’t be sure about the engine’s status, as has been said.

You can drop the oil pan and inspect bearings & journals…

Pretty big job, but….

I took off the oil pan cause I thought my oil pump was bad. Everything seemed ok with my untrained eye.

 

[45Dougal]

Take your rocker cover off, and check to see if you dropped an intake valve.
Maybe it didn't seize. This would explain your lack of vacuum.

 

[Jaws87]

Take your rocker cover off, and check to see if you dropped an intake valve.
Maybe it didn't seize. This would explain your lack of vacuum.

Ok. I will check that. Thanks!

 

[peesalot]

Zero vacuum while cranking & " I checked compression" don't add up ? Meaning if it had comp it should have vacuum unless the cam is broke or as noted above , out of time badly but then it should have good comp #'s either ?

 

[Jaws87]

Ok. I will check that. Thanks!

Zero vacuum while cranking & " I checked compression" don't add up ? Meaning if it had comp it should have vacuum unless the cam is broke or as noted above , out of time badly but then it should have good comp #'s either ?

 

[pjohnson]

I took off the oil pan cause I thought my oil pump was bad. Everything seemed ok with my untrained eye.

You need to pull bearing caps to inspect bearings. There is at least one that is likely fried, but all may be damaged. If you can find the oiling path diagram, I would start with the first rod or main bearing that gets oil from the pump and work out from there.

IF you are very lucky, you MIGHT be able to replace a bearing and keep going, but I would defer to @cruisermatt on the probabilities of being that lucky.

 

[Chungas Revenge]

IF you are very lucky, you MIGHT be able to replace a bearing and keep going.

word..

 

[Jaws87]

You need to pull bearing caps to inspect bearings. There is at least one that is likely fried, but all may be damaged. If you can find the oiling path diagram, I would start with the first rod or main bearing that gets oil from the pump and work out from there.

IF you are very lucky, you MIGHT be able to replace a bearing and keep going, but I would defer to @cruisermatt on the probabilities of being that lucky.

Ok thanks! Any good videos of this being done? Or is it in one of the service manuals? I’ve never poked around down there.

 

[45Dougal]

View attachment 3446569

View attachment 3446570

It's hard to see on the photos..
You're looking for a loose rocker (as if a valve has dropped down partly).
Try turning the engine by hand to check them all

 

[73FJ40]

"letting it run for 15 to 20 seconds at a time" How many times?

 

[peesalot]

whats the bottom of dist look like ?

 

[Jaws87]

"letting it run for 15 to 20 seconds at a time" How many times?

Not sure. 6 or 7 times probably.