90 mx-5 died on me :~(

Well, hopefully there's a resurection in its future. Maybe someone on this group can lend me a hand. Sunday, as I sat at a stop light in my 90 miata, I noticed a slight whirring noice, but not even so much of one that I could tell whether or not it was anything more than my head messing with me. I still think there is a chance that it was my imagination, but the events that immediatly preceded my noticing the noice would cause me to think otherwise. As the light turned green I turned left to find that all of a sudden my engine had died. I had enough of a roll to pull into a parking lot, where I found that the starter would turn the engine over vigorously, yet the engine wouldn't start. I immediately checked the fuses, to no avail, yet I found that the plugs were not firing. I towed it back to the house, and now I'm left wondering what to do.

Some background: I love my car, which I purchased from my brother 3 years ago. It has just hit 125,000 and had been showing no signs of engine trouble whatsoever. While I change the oil regularly, I am ashamed to say that my financial situation has not allowed me to give it as much maintenance as I would have liked (!I have not changed the plugs or wires since I've purchased it... insert insulting remarks here.) although I was able to scrape together enough money last summer to get a badly needed paint job. My financial situation leaves me with no opportunity to immediately spend anything over $200, and I fear that it may require more...

Ok, back to the problem at hand. I wonder if my coil pack may have gone out on me, although I realize there are other things that could result in the same scenario. I am wondering what I can do to narrow the field as far as what may be causing my problem. Could it be that neglect of those plugs and wires could have resulted in an all of a sudden loss of spark (One second she was running strong, the next she was dead) My limited knowledge of engine electrical systems would lead me to think that while those old plugs and wires are probably not helping anything, they probably aren't the cause of the problem at hand (let me know if I could be dead wrong.) I live in a pretty small town in arkansas, so a mazda shop is pretty out of the question. If I can find out what is wrong, and can purchase the part, as long as I don't feel that I'll make the problem worse than I'll do the work myself. If necessary I'll take it in to a mechanic to plug their computer in, but I don't know how they'll feel about giving me a diagnostic just to have me tow it away and fix it myself.

Reply to
jacobo chiquito
Loading thread data ...

You might be able to get some knowledgeable help from another Miata owner in your area.

If there is no spark it could be a coil pack. Bad wires and plugs will hasten the failure of a coil pack. As the gap widens and the plug wires deteriorate, the load is reduced on the pack and the peak voltage increases. The higher voltage breaks down the dialelectric (insulation) in the secondary winding of the pack, and the winding shorts out.

Other problems can also occur as a result of a neglected ignition system. The unburned fuel from the cylinders that are not firing will make the O2 sensor try and lean out the mixture. And the O2 sensor can be damaged. And then the catalytic converter overheats and becomes damaged. About that time the car fails emission testing. (blah....blah...blah)

Reply to
Larry Gadbois

Have you ever changed the timing belt? I'm not sure how a broken timing belt would affect spark, although the angle sensor wouldn't be sensing anything because the cam isn't turning and therefore wouldn't fire the plugs (?). Fairly easy to tell, remove the oil filler cap, turn over the engine and look at the cam lobes you can see through the filler hole. If they aren't moving, your belt is gone. If you are mechanically inclined with access to the appropriate tools, the belt package itself (seals and tensioner spring included) is inexpensive. If you're not comfortable with doing it yourself, your going to need to double your budget of $200.00 to get it done professionally. Unfortunately, at your mileage, the other belts and water pump should also be done which has now tripled your budget. Make sure you, or your mechanic, read the information on miata.net about the crank problems on the 90 miatas - print it out and follow the instructions to the letter or you'll be buying an engine.

Tom

92 Red

jacobo chiquito wrote:

Reply to
Tom Howlin

No

Thanks, I'll check that asap, at university at the moment, but I'll check later today. If that is the case, I'll fix that myself.

Thanks tom, you've given me something to check, and even if it's not the problem, I'll at least feel that I'm starting to narrow down the field. Could a broken timing belt be immediatly precipitated by the whirring noise I mentioned earlier?

Jacob

Reply to
jacobo chiquito

Could a broken timing belt be immediatly precipitated by the

Since I'd planned on posting, I'll step in for Tom and say yes; the whirring noise could very well have been the timing belt coming apart. The job was due at 120K (assuming it was changed at 60K as it should have been), so you're right on schedule for a break. Luckily, the Miata engine isn't closed; the valves don't hit the pistons if the camshaft stops and the engine doesn't, so if it is the belt, a new one should have you up and running again. Be sure to read up on the dreaded crankshaft problem that the early Miatas were prone to, so you get the belt changed without creating a potential disaster. And consider changing the water pump just on principal while you're in there.

formatting link
My 90 Miata (120K miles) died on the freeway one night. It turns out the crank pully had loosened it's bolt, and spun off. I got under the hood and jiggled the pulley and it was loose in my hand. I thought I was sunk with a busted crankshaft, but it wasn't. The pully had simply come off. So...a new timing belt, pulley bolt and key and a very good torque wrench had me back on the road. Napolean now has 153K miles, and isn't showing any signs of quitting. Remarkable little cars....

Walt

Reply to
WJ

On Tue, 02 Mar 2004 03:47:12 GMT, snipped-for-privacy@yahoo.com (jacobo chiquito) wrote in news: snipped-for-privacy@posting.google.com:

I second the timing belt motion. (or lack of motion)

I had exactly the same thing happen to me a long time ago.

The key evidence is the way the engine seems to run more quickly when you try to start it.

I'm sure there are a couple of quick verification tests you can do to prove it. (or not)

Reply to
Dave Null Sr.

Yes. The belt could have been in the process of fiber separation and pieces of it were hitting the timing belt cover and as soon as you accelerated, the increased velocity snapped what there was remaining of the belt. Fortunately, the Miata has a non-interference engine and so the likliehood of any damage beyond the timing belt is small. Good luck with it.

Tom

92 Red
Reply to
Tom Howlin

Wanted to followup here, I checked, as suggested the movement of the cam lobes as I turned the engine over. Sure enough, no cam movement. For a second I held my breath wondering about bent valves, but as I got back on here to post my findings, I was releaved to find a few say that wasn't the case. So, this timing belt change shouldn't prove to be too difficult eh? I'm kind of happy to find that my wallet shouldn't be hit too hard. A couple questions. Can I be sure that this is the problem and go ahead and purchase replacements? What other things do I need to replace. Tom suggested the other belts, which look like they need it, as well as the water pump suggested by both tom and WJ. Is there a way I can check the status of the water pump or is this something that I really should just do. While I really can't afford to spend (really any money at all) I recognize that by allowing things to get worse I'm just looking at more money and heartache down the road, maybe even soon. How much money am I looking at seeing as how I'll be doing the labor all myself?

And thank you all for making me aware of the crankshaft issue. I plan (hope) to do the work thursday, so I will familiarize myself with miata.net's info on it.

Thanks again for the help, I kind of felt dead in the water. Now I can see the light at the end of the tunnel. I really feeel that my car has done me so well, I love it, and I really appreciate the online community.

Jacob

Reply to
jacobo chiquito

If your front cover crankshaft seal isn't leaking oil, it's possible to do the belt replacement without disturbing the crank pulley bolt, by just unbolting the lower pulley from its hub. My Haynes manual illustrates the procedure that way. That's considered to be the safest route in terms of the early Miata's potential crankshaft problems. In that case, all you'll need for sure is a new belt and the cover gaskets. You can order a timing belt kit that will have all the gaskets and seals along with the belt. Look over the water pump really good while you're in there. If it's seeping coolant out its bottom weep hole, or if it's pulley feels the least bit strange when you turn it, replace it even it you have to spend the next month eating skinny. I'm tempted to advise you to replace it regardless, but I've been broke a time or two myself. You will need a manual of some sort; the timing marks for the crank and two cam sprockets are not obvious or easy to get lined up correctly.

If the front cover crankshaft seal is leaking, I would go ahead and replace it if I were in your shoes. In that case, you'd need the seal (which may come with the timing belt kit; I'm not sure), and a new pulley bolt and key. None of that's expensive, but it will add a bit of work to the job. You'd also need a top quality torque wrench to get the new pulley bolt torqued

*exactly* to spec, and maybe a puller to get the hub off the end of the crankshaft. These kinds of things can be rented or borrowed, but don't just settle for any old torque wrench. I got a chunk of angle iron and cut/drilled one end to bolt onto the pulley hub so I could hold the crankshaft while I torqued the pulley bolt.

I don't remember what the timing belt cost when I did mine. I just remember that it cost a lot less than the new crankshaft I thought I was going to have to get .

Good Luck, Walt

Reply to
WJ

I have a question about the timing belt. Since it sits right there in front, I assume one can tell if it's gone? Since the shredding can happen first, I assume one can tell if the timing belt is missing altogether?

Thanks ~Cissy '89 Miata

Reply to
Expmiata

Miata

On a stock 1.6L Miata (only ones I have direct experience with), the timing belt is fully enclosed so you can't see it. It's under those two humps at the front of the valve cover. You can inspect the timing belt by removing the valve cover. One way to see if it's broken without pulling the valve cover is to look down the oil filler hole while someone cranks over the engine. You can see the left camshaft in there, and if it doesn't turn with the engine, it's 99% sure that the timing belt is broken. A timing belt generally has only three conditions:

-good condition (looks basically undamaged, might be a bit scuffed on the edges)

-starting to fail (you have maybe five miles if you're lucky; they don't last long once they start to go)

-failed (car won't run)

The belts are designed to last 60k miles or 48 months according to my manual. Pushing the limit is just asking to be stranded somewhere, but at least with a Miata the head and/or pistons aren't damaged when the belt goes out like on some cars. But the trick is still to replace it before it fails, because they usually don't give fair warning.

Cheers, Walt

Reply to
WJ

Thanks, Walt ~Cissy '89 Miata

Reply to
Expmiata

Allright, in the middle of it now, as I deposit a layer of grime onto the keyboard here, my step father has gone to get a socket to turn the crankshaft. A few questions I'm worried about. the instructions from miata.net say to rotate the crankshaft twice until the left cam is lined up w/ a particular mark. only problem is, with no timing belt (oh btw, it was the belt, snapped clean) turning the crankshaft doesn't turn the camshafts! I'm wondering how I'm to line the camshafts up so that their alignment is correct. Can I just set the camshafts to their marks and that will be fine? We haven't turned them since we opened it, can I expect them to still be aligned and turn them together bylaying the broken belt across the top and pulling it right? I'm crossing into uncharted waters as far as my own experience goes, definatly a learning process... I just need my timing to be correct... obviously! the article from miata.net advises seeking pro help if the cam's are off, and as I've said before that Isn't an option...

ok now, going to read the timing article on miata.net

btw thanks for everyone who's given advice so far, this board is where I was able to get the information to determine the problem, and it was dead on!

Reply to
jacobo chiquito

Check out

formatting link
for detailed instructions and pictures of timing belt, idler tensioner, cam and crank seal replacement.

Reply to
Michael Cain Sr.

About two journals back on the cams you will find a hex cast into the cam. You can put a large wrench on these hexes and turn the cams to the correct position. It may not make any difference, but I would only turn them clockwise since that's the way they normally turn. I find that it helps a lot to put a wrench on each cam and wedge it in place somehow to hold the cams in the exact correct position while installing and tensioning the belt (if you have a helper this should be easy). When I put mine back together it was so well lubricated that one or both of the cams kept springing to one side or the other, slightly off the mark, making it hard to get the belt on both of the cam sprockets without slack in between. The wrenches made it much easier. Then you can release the tensioner before removing the wrenches, re-tighten the tensioner, remove the wrenches, turn the crank

1.3125 (?) turns to the other mark (~8 o'clock position) and re-loosen then re-tighten the tensioner to set the correct tension. At least that's how I remember it from my '94 1.8L (just realized you have a '90).

John McClary ('94 Miata) jsgmcclary at cox dot net

Reply to
John McClary

I'm currently slightly over 100k miles and somewhere around 120 months on the original timing belt and it hasn't failed yet.

I like to live dangerously.

Reply to
tooloud

Suggestion: If you decide to get religious about this, don't touch the crankshaft bolt and pulley unless the front oil seal is leaking badly. If you do, read the "loctite" articles carefully, use loctite even if everything looks OK and pay the $25 or so for a new crankshaft pulley.

Best,

Ken

Reply to
KWS

Hey, man, I finally changed the rear pads and installed a new caliper last weekend after having the car sit without them for about six months. That timing belt goes anytime soon and I'll be speed-dialling a mechanic friend to take care of the problem.

Reply to
tooloud

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.