Help! I've got no acceleration!!

I have a 1990 roadster, which up until now has given me no trouble and goes like a dream. Since Monday, when I try to accelerate from 1st or 2nd gear I crawl away at 5mph with my foot to the ground! I have to get the revs up to 2000 before I can pull away. I have tried new spark plugs and new HT leads to no avail and have bought a new air filter which I will fit tomorrow. Does anyone have any ideas?
I would appreciate any help.
Thank you

Might be worth checking that the HT leads are connected properly at the non plug end (cant think of the name for it!)

I had a similar problem with mine, one of the leads had worked its way loose


Hi Penny, I hate to suggest this, but have a look at this post

There is a known problem with the crankshafts on early Mk1 cars, and they exhibit similar symptoms to the one’s you describe. 

Or a slipping Clutch? Maybe a coil pack going down?

If it’s the clutch the engine revs will rise but you won’t go very quickly until the plate finally bites, a test is 2nd gear about 10mph and floor the throttle, if the revs go up and you don’t go faster it’s more likely the clutch.

Coil packs will cause misfires and sluggish performance to total failure. Hope it turns out not to expensive.


I have a '91 1.6 that has the same pulley as the lower of the two photo’s in your link. Does this mean that the issue has been resolved on my model/year?

Could it be something as simple as the automatic choke not working?

If you have an 8 slot pulley you have a 1.8 engine. Is the lettering on the cam cover raised or recessed?

Bit of a typo there I think; 8 slots on a '91 is not a 1.8 engine, but a 1.6 with the revised crank nose.  1.8 didn’t appear until 1993.

Hi Martin, I stand corrected, I think. I thought that only 1.8 engines were fitted with an 8 slot pulley, thats why I asked about the lettering on the cam cover.-----

Sorry about the confusion but, does this 8 slot pulley mean that I don’t have to worry about it becoming loose?



Hi Gary, it means you don’t have the early LWSC crank. Failures of this newer version are far less common, but you still have to take the same care as on the earlier cranks. Contrary to popular opinion later cranks do fail in the same fashion.

I’m still curious to know about the lettering on your cam cover?----

 Confused here as my crankshaft pulley doesn’t have any slots so what have I got?  Its a 09/91 UK 1.6 model.

Are you sure you have a 1.6 twin cam Mazda engine? Maybe someone slipped in a fiesta one in replacement[;)]

Look again, all the Mk1 engines that I have seen have slots in the bottom, crankshaft pulley—…but you may know something different 

 This is mine…what the hell have I got?

 Well, that looks a lot like my 1994 1.8 to be honest.  Do you have a general pic of the whole engine bay?

Trying to locate an engine number but exactly where on the engine and what I am looking for is proving to be difficult.  My log book states that it is 1.6 and the crank angle sensor on my engine is on the drivers side. From what I can gather on this and the Miata forums, it would be on the other side on a 1.8.    According to the service history, the car had a timing belt change and I am wondering if the outer pulley was replaced or the standard setup modified due to problems with the original keyway and slot. I guess there is no way of telling untill the next cambelt change is due or the pulley fails.

The pic is a 1.6 UK car. The tell tales are the CAS is on the inlet side and the coil pack is on the exhaust side. The lettering on the cam cover appears to be inset and you have a socking great resistor in a heat sink next to the AFM [to do with dim/dip]


It’s all in the faqs=====

 Thanks for the confirmation Geoff and the link. The outer pulley seems to be incorrect according to this thread. What form does the engine number take, is it a casting or a plate? I can see the location from the link you supplied but cannot see any engine ID in that area.

When I finally sorted my engine number about 6 blokes all looked and gave different numbers, my mate Roadster Robbie was the one who finally worked it out. The chalk you see in the pic is to indicate the part of the block where the number is stamped, do the same, and then wipe the excess chalk off, sometimes the chalk is held in the stamping marks and you can read the number  HTH  -----


PS No idea on the pulley, a two part pulley strikes me as a bit strange, however I’m sure someone will have the answer