3F Troopcarrier sudden loss of all compression

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Mar 16, 2023
I bought my dream car a 1989 FJ75RV TroopCarrier a month ago. It had driven well for a month and I have replaced all fluids, spark plugs, adjusted valves, and timing. Ready for re-registration next week... so I thought!!

3 days ago it just simply died while driving. No mechanical noise/clunks etc. Pulled to the side of the road and when trying to start the engine spins high/lose. As if no spark plugs are present. Towed it home.

Since then I have read about timing gears etc. and read few experiences in this forum such as they can be lose 10deg. etc and checked the following:

- The valves and distributor rotates, which eliminates timing gear failure issues
- Can see that at TDC mark cylinder 1 valves are lose and 6 are tight as per FSM
- Did compression test on cylinder 1 and showing 0. Put tablespoon of oil and still 0

I will do leak down test to see where the air is escaping. But I am a bit puzzled why no compressions at all on ALL cylinders at one time? I was "hoping" it was a simple timing gear failure. And burnt valves do not happen all at once. Any clues where else I should look at? I am new to this engine.
With ZERO compression across ALL cylinders, it sounds like the timing is WAY off and/or the valves are slightly bent holding open. Anything else that could cause zero compression would have made a horrible bang noise, and you never heard that.

It sounds like you are able to check the timing, since you adjusted it last month. Do all the marks still line up?
Yes I am still able to adjust the timing fine.
- When I rotate the crank I can see the rear TDC mark moving (eliminating snapped crank)
- At TDC mark the valves are in correct stage e.g. compression on cylinder one, and after 360deg on cylinder 6

Bent valves are a suspicion although I have read 3F are non-interference engine (?)
OK so I did troubleshooting from scratch tonight. Checked TDC manually by poking a stick and confirmed the marker lined up. But on both compression and exhaust cycles the valves were NEVER lose! So that concludes that there is timing gear issue:
- Possibility of jumping teeth
- The fibre timing gear has worn off and wobble as per this thread and maybe worse than his (his car was still running):

Either way glad to find out there is no mystery and I can get on to fixing it as per specs. I just hope that my reading is correct that the 3F is a non-interference engine and will not bend valves.

This also explains the whole event from driving to losing power all of the sudden without mechanical noises. If the fibre timing gear had moved there will be no compressions and the car simply coast, which is what happened....

I will update...
i know what happen ,

a fuse in your fuse box ratted loose ....

the black wire w/ yellow stripe is now helpless ...

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