Disappearing power!

[mid life 5]

How wobbly is the wobbly crank syndrome, mine moves slighty by a mm or two, cheers peter.

I will be in Ipswich over the weekend and can have a look if you like..

That will be great, i'm at springfield lakes, sat or sun, cheers peter.

[JBT]

The problem is this (see attached) if the key-way is stuffed. The wobble may or may not be apparent.

[corners]

The problem is this (see attached) if the key-way is stuffed. The wobble may or may not be apparent.

Ouch mine isnt that bad!!!!

[mid life 5]

Is there a way to test the afm because last night i noticed while the engine was running, and it was idling nice and smooth that when i cut the engine there was a clunk from inside the afm, I've never noticed that before. My son has a 1990 1.8 tx3 laser which has an identical looking afm, can i fit this on my motor to test out, if not is ther another afm from a mazda or ford i can get from a wreckers to try, cheers peter.

[JBT]

The clunk was probably the AFM vane closing normally. If the AFM is not working the engine won't start.

Another way to help detect a very worn key-way is to do a TDC check. Take out the #1 plug and insert a long screwdriver, length of wood dowel or similar so that it sits on top of the piston. Turn engine by hand until the screwdriver reaches it's highest point. The timing mark on the pulley should be at TDC. If not at TDC, you have a problem.

[mid life 5]

The clunk was probably the AFM vane closing normally. If the AFM is not working the engine won't start.

Another way to help detect a very worn key-way is to do a TDC check. Take out the #1 plug and insert a long screwdriver, length of wood dowel or similar so that it sits on top of the piston. Turn engine by hand until the screwdriver reaches it's highest point. The timing mark on the pulley should be at TDC. If not at TDC, you have a problem.

Tried the tdc check and it's all good, timing marks lined up perfectly. Tried another afm and its just the same, one other thing i noticed is after the engine was running (for only about 20 seconds) was the extractors were red hot, is this normal. Is it worth pulling the exhaust off from the collectors and trying it, be a bit loud but would eliminate a blocked cat or muffler, cheers peter.

[JBT]

I reckon it's time to pull all the front bits off the engine and check out the timing belt setup and the crank pulley/key-way condition.

[mid life 5]

Ok, i pulled the front of the engine off this morning and guess what, it's nearly as bad as the picture above. So what's next, do i get this rebuilt or buy another engine, how much roughly am i looking at either way. It's bloody typical, i lost my job last week after 15 years service and as this is my only car, i need it to get around for job interviews, thanks for all your input, cheers peter.

[JBT]

Bummer.

Your options really boil down to the "loctite fix", a replacement engine or rebuild the current engine with a new or undamaged crankshaft.

The loctite fix has a 50/50 chance of working and enduring. http://www.miata.net/garage/hsue/crank/loctite_1.htm

A replacement engine (with long nose crank) would be my pick. Try MX-5 Plus for price/availability.