why would my jimny lose compression sometimes?

hi this morning i got into my 2002 dohc jimny and turned the key it turned over nomally and fires for about 2 seconds then died when i turned it over again it sounded really weird as though it was turning over without the timing chain on (no compression sound) the only time ive ever heard this sound it when my laguna timing belt snapped , i ended up walking to work bahhh
when i got home i tried the car again and it turned over and turned over for ages before not willingly coughing into life , ive run the car for 20 miles without a hiccup starting it up and turning it off , its done this before about 6 months ago any ides what to try?
first im thinking the timing chain has slipped but if its starting it cant be?

Is the starter turning the engine over or is the starter not engaging and is just spinning it's self? The drive went on my Jimn's starter a few weeks ago & I had it rebuilt with a new drive. It sounds a little like it's spinning the engine over without compression but sometimes catches so turns the engine over, making it seem like you say in that it had no compression and then it returned when it was the starter all along.

I suppose you could get someone else to turn the key while you look at the engine and see if it's actually turning over when it makes the noise.

Kirkynut

yeah that sounds about right kirkynut . replaced my starter about 4 weeks ago. sometimes it would sometimes it wouldn't ( not ideal offroading ).
seems like what jamesy is experiencing. starter failing to engage.

i suppose it could be that ive never seen if it actually turns the belts round?
it does start the car eventually if you keep cranking but it really struggles because of the unused fuel in the system so saying that i bet the engine is turning?

Mine has done this. It is getting flooded and the fuel is washing the bores and pistons. This can lead to the rings gliding up the bores instead of sealing. New plugs, especially if they are the iridium ones may help, or replace the coolant temp sensor (it may be over fuelling).

When it restarted it would have gone onto one cylinder, than another and then another finally coming to life?

Foot flat on the floor?

If so sounds familiar