Shut off and wont restart

[Cruisers460]

OK, seems like I just make it over when something goes wrong...... 2002 NB 225000 miles

Wifes driving to work last week downshifted for a turn and the engine died. I towed it hone and can't get it to do anything but turn over. I've confirmed that the fuel pump comes on, but it wont even sputter on starter fluid, changed the main green relay and also the crank position sensor. Fuel filter has about 15000 miles on it and the cam sensor is fairly new. Fuses look good but the 100amp fuse will not pull out of the box. So what else should I be checking? Car was running great when it shut down. No trouble codes from the engine. Thanks

[SONICZM]

Check for spark. May be the coils.

[iscariot]

Fuel, Air, Spark, Compression.

No cough on starter fluid indicates no spark. No spark on either coil indicates a sensor malfunction, not a coil problem.

Replace the cam sensor. Yes it's new, but if it's a cheap sensor it's always good to keep a spare in the glovebox anyway.

[iscariot]

After edit - died on a downshift? Probably stripped the timing belt. Have someone crank it while you look in the oil fill and verify the cams are spinning.

[Cruisers460]

OK, looked into the oil fill, Could only see what looked like a pillar block and a short piece of shaft with grind marks. Nothing moved when the engine was spun over. I'm assuming that the short shaft with the marks was the cam? Never had the cover off the miata engine to be familiar with it.

Ok googled miata cam images, looks like the timing belt is gone.

[CAKELIE]

Good news is that it likely didn't destroy anything. Time for a timing belt! Make sure you replace all the seals and water pump while you're in there. Use OEM seals only.

[Cruisers460]

This one only has about 30k on it, radiator was full but when I popped the cap the water pump started leaking. Didn't think the 2 were related but starting to wonder.

[iscariot]

So "Downshift" was the keyword in your diagnosis - Many years ago, I messed up doing a timing belt - more specifically, I messed up the crankshaft seal. It was leaking oil all over the timing belt. I knew the timing belt was compromised from the oil, but my garage was in use by my daily driver and just needed the belt to last 6 weeks before I could get the daily running and go back and fix my mistake. It lasted 5. Downshifted coming off the interstate, and yeap, miata became a static display.

So when you pop the valve cover off - look for oil on the belt, check your seals. My guess is something in there compromised the timing belt.

[Cruisers460]

About 5 inches of teeth stripped from the belt. Best guess is premature water pump failure with just enough of a leak to wet the belt but not enough to be noticeable.

[boatshoes]

Water pump gone at 30k? Mind sharing the manufacturer of said water pump?