Can't remove crankshaft timing belt pulley BOLT!

You will have to brace the crankshaft somehow, either by way of the flywheel, or the pulley. The trick to getting the bolt to break is "heat". Propane will sometimes work, but it's generally not hot enough. You want to get that bolt glowing if you can, and hit it with air impact then. Be careful not to burn yourself!

I hope this helps you, and I wish you luck on your repair.

This is a simple problem to solve.
To replace the timing belt the mark on the camshaft pulley should be aligned with the engine block/valve cover and the mark on the crankshaft pulley should be aligned with the mark on the engine block.
The marks may be a white mark or an indentation.

When this is done one of the cylinders will be at TDC (Top Dead Center). In this position the ALL THE INTAKE AND EXHAUST VALVES IN THAT CYLINDER WILL BE CLOSED (compression stroke). Get the correct cylinder. Remove the spark plug in that cylinder. Back off the piston slightly and pack a length of a small diameter rope into the spark plug hole until full. Leave one end out for removal! Now when you turn the crankshaft nut the piston will push against the rope and the engine will not turn. You can get a manual from the library, auto supply shops or internet.

Some books suggests compressed air with a sparkplug adapter. That's elaborate and too noisy.

Make sure those marks are aligned on final assembly ! The valves will hit the pistons if not.

For my '92 Mazda, a tool supposedly exists for holding the crankshaft by the pulley bolts while you use a breaker bar on the crankshaft bolt. Mazda could not find it in their parts system, probably because it was too long ago. I finally went back to the starter method with the braced breaker bar on the crankshaft bolt. I had to charge the battery to make sure I had maximum power to the starter. I bumped it a few times, checked the socket to make sure it wasn't slipping off, bump a few more times, took the socket and breaker bar off and turned the engine to a new position and repeated all that in 3 or 4 crankshaft positions, so I wouldn't be hitting the same spot on the flywheel every time. After about 40 bumps with the starter, the bolt finally came loose.

You need a "Crankshaft hold" tool which screws into the pulley using the same screws that hold the larger pulley on while giving room to still get an impact socket on the crank bolt. As the 91-94 Mercury Capri use a Mazda 1.6 Engine (which are much more popular than the Capri) you can use a Mazda Miata crankshaft hold tool. Can make your own from scrap steel and a oxy torch if you have - or buy one from flyinmiata.com or the ebay store "mazdamecca. Some good videos on Youtube if you search for Mazda Miata Crankshaft keyway.

Don't recommend you torch the bolt as some other folks have suggested as there is a seal behind it as well as the chance the bolt would lose its temper.

Also don't recommend the technique of putting the breaker bar on the bolt and running the starter (50/50 shot the starter gear will break before the bolt breaks lose).

Once the proper pulley hold tool is in place you can really bear down on a breaker bar - giving it a few sharp wraps with a small sledge hammer helps break it lose. Impact should work as well if you have a strong enough compressor to supply enough torque.

I understand. and i have found ways to get around it.... but i'm sorry, i cannot tell you. they are horribly unsafe, and i'm not having that on my consience. all i'll say, is that if there is anything attached to the pulley (the timing belt) or anything that is indirectly attached to the pulley (the crankshaft and inherently the flywheel) holding any of those still with a well placed screwdriver will help. please be careful...