Cold Start Rattle
 

Howdy,

New member, this is my first thread.

Actually I just posted a pic of my 2002 in the NB Miata Picture thread.


But my issue is this: Upon cold start, (only) after it has sat for days, I get a rattling/clattering from the engine, fairly loud.

When the car has sat for a day, no noise.

When the car has sat for a week, it rattles for one second.

When it sits for 3 weeks, it rattles for 3 seconds.

5 weeks or more, it rattles for 3 seconds.


I run 5-30 Mobil 1 with a NAPA Gold filter.

90k on the engine, no major mods.

This started at 85k.

I've since changed the filter.


On someone's suggestion two years ago, I began to first turn over the cold engine by pushing the accelerator to the floor and cranking for 5 seconds. The engine does not start during this mode.

Then it starts up fine on the second turn of the key.

This procedure has eliminated the rattling noise. Completely.


However, I don't know if the fully depressed pedal disconnects the ignition or the fuel.

If it cuts the ignition, then the combustion chambers might be getting flooded with fuel, washing the oil off the walls, and causing inordinate wear during startup.


If it cuts the fuel injectors, that would be preferable.


Anyone got an answer to this?

Thanks

https://cimg7.ibsrv.net/gimg/www.mia...c448e81b6f.jpg