Erotomania

I just picked up my first miata and also my first experience on anything other than a honda. I wasn't planning on buying one quite yet but I found this one for 750 bucks, 1990 5spd 1.6 with all the options. It was repainted black but looks to have originally been blue or teal, with a dark almost navy blue interior. Its in pretty rough shape, but my goal is eventually to rework the whole car so, the current condition doesn't bother me. The owner said it blew a headgasket and it wouldn't run. I haven't tried starting the car up, I picked it up with the plugs already removed and I can see a light layer of fluids sitting in cylinder #2 and #3. So the obvious is it needs a new head gasket, I'm also assuming the head will need to be surfaced again. I started trying to tackle pulling the head off and quit thinking maybe I should do some research or ask a few questions before I waste too much time. My searches have landed me a lot of useful knowledge but not much on what I'm looking to find out. Am I correct to assume that I can just remove the Intake manifold and exhaust manifold(and down pipe obviously) from the head and set them aside and pull the head off? I tried loosening the timing belt tensioners but they really didn;t want to budge at all so I'll have to give that another shot. I also removed the electrical plugs on the firewall side of the head for the cylinder sensor and a few other things.

Am I missing anything important? or am I thinking on the right track?

Also, should I worry about the bottom end? What should I do to clear all of the mixed up oil out? drain it all and refill it with new fluids, run it and repeat?

Just looking for some knowledgeable advice. I don't like to run too far on my own assumptions of how things work. Its pretty weird working on a motor mounted backwards!

I also noticed numbers written on the valve cover in grease pen? Would this maybe mean it has a new motor put in it? Is there anyway to check if the motor is original to the car? Or if it is even a 1.6 and not a 1.8? I have no clue about the history of this car but its been around for quite awhile and who knows whats been done to it.

Thanks

zoomin

iTrader: (16)

It's usually easier to just pull the engine and transmission out of the car as a complete assembly to work on it. Replace the front and rear main seals, rear CAS seal, might as well replace the clutch and bearing, clean off the years of grease and dirt, and then put it back in. And you don't need to remove the intake manifold to do the head gasket, just make sure the sensors are disconnected.

akaryrye

iTrader: (5)

1.6 has indented letters on the cam cover, and the cam sensor is on the passenger side. 1.8 has raised letters and cam sensor is on the drivers side. To pull the head, you will need to get that belt off of course, pull the plugs and the heater line off the back (careful not to mess up the copper heater core lines that come out of the firewall.

Cover up the oil ports please when you pull that thing.

samnavy

iTrader: (7)

You're exactly on the right track. Don't forget you might want to drain the coolant and unplug the battery before you get started. You'll be working in close proximity to the alternator.

The exhaust manifold comes off without a hitch, except at that age, I HIGHLY RECOMMEND YOU LET EVERY NUT/BOLT YOU INTEND TO REMOVE SOAK IN PB-BLASTER or LIQUID WRENCH OVERNIGHT, INCLUDING THE BOLTS AT THE MIDPIPE!

The intake manifold is similarly easy. There are zero tricks or "gotcha's". There is an intake manifold brace under the IM that secures it to the block... no need to re-install that when you remove it. It was severe over-engineering by Mazda and is completely unnecessary. Some of the intake manifold nuts are a little hard to get to. Experimentation with an array of extensions/swivels will get you in the right direction.

Check these threads from when I did mine:
https://www.miataturbo.net/forum/t14714/
https://www.miataturbo.net/forum/t14979/

If you've got oil mixed with coolant and vice-versa, you'll need to drain the fluids. If you're paranoid about it, just fill back up with water and the cheapest gas-station oil you can find. Drive for a couple days, and then change fluids again with the good stuff. If it's freezing where you are, then obviously plain water won't work.

The block is iron, and it'd have to be severly overheated to warp. It would be a mistake not to have the head planed flat as a precaution... as you can see in my linked threads, I failed bad there.

Additionally, WELCOME TO THE FORUM!
Since I was so awesome to hook you up with some old threads, please FILL IN YOUR PROFILE WITH YOUR LOCATION, and PUT SOMETHING IN YOUR SIGNATURE, LIKE THE YEAR/MODEL/MODS OF YOUR MIATA.

Additionally, WELCOME TO MIATAS!
Don't forget before tackling any routing/standard maintenance to consult the The MX-5 Miata Pit Stop: MX-5 Miata.net GARAGE. Just go to the website and CLICK the link for the garage on the left-side of the main page. You'll want the ENGINE/DRIVETRAIN section for this one... but while you're there, check out the rest of the AWESOME writeups and how-to's others have done.

Erotomania

Thanks alot guys. Those threads were really useful. I've pulled and rebuilt a couple honda motors in my short years and the miata seems to be a little more user friendly its just different.

I'm hoping to get this thing in running shape here soon so I can figure out what else is wrong haha

I've got lots of body work to pay attention to and I'm really itching to get rid of some stuff under the hood. No need for wiper fluid or cruise control or any of that ugly junk! It's gonna need new fenders, finish panel, tail lights, and a new top. The plan is to widebody it, build a 1.8 and turbo the snot out of it!

Thanks for the help guy's I'll put up some pictures once I think its presentable.

Erotomania

Well, I pulled the head off. Removed the old gasket material, checked the head with a straightedge, it looked pretty straight so I just tried putting a new gasket on to see what would happen. Long story short, It wont start haha. I marked the timing belt positions and the teeth are where they originally were, so I'm assuming thats correct but even if the marked teeth are matching could it still be off? I dumped all the fluids replaced them, put new plug wires on, new spark plugs, added a little fresh gas. Fuel pump is pumping, plugs aren't fauled. Oil is staying oil and coolant is staying coolant. I'm kinda at a stand still. The only thing I can think of is maybe the timing belt isn't lined up correctly. Without removing the TB pulley is it possible to get the engine to TDC and check the marks on the cam pulleys from there?

Anything else that would stalling it? Its turning but not even trying to start. I can't get out of the car and try starting it to listen for injectors clicking but I'm assuming they are doing fine.

The car didn't have plugs or wires when i bought it so, Who knows if it would have started from day one, so I don't know if I'm at a preexisiting problem or a new one.

Help?

Thanks!

olderguy

iTrader: (19)

If it is the '90 engine, you can get the timing belt cog visible to check its' position without removing the timing belt, but you will need to remove all the front covers all the way down. The Miata.net timing belt writeup will give you the positions of the gears in relation to each other and the belt.

I would go the next step, however, and remove the bottom t/b cog to check the keyway and crankshaft, do the locktight fix if needed, and replace the main bolt either way.

y8s

iTrader: (8)

PS make yourself a nice new "hi I'm new" thread in the Meet and Greet section.

Erotomania

If my belt was on the teeth I marked, is it still possible to be off?

The car has sat for some time, is it possible the coil packs are fried? How can I tell if my igition system is working correctly?

I know I can listen for injectors and etc but I have no clue about the igition system.

I am trying to make a check list of things to check before I start poking around again.

samnavy

iTrader: (7)

No more help until you fill in your signature and profile info.

Toddcod

iTrader: (8)

People here can be butt holes..... You off to a good start.... But just to make everyone happy please go to your profile and state your car Profile info to keep the notzi's off.

And just for giggles make a quick meet and great thread.

CHECK TIMING MARKS AND GAS.......THE GAS MAY BE BAD

Find the fuel supply line, un hook it and run the line into a clear liter bottle, have a buddy start it. This will let you see what quality of gas you have. It bet you have bad gas......The new gas doesn't last like the old gas. It will go bad quick. And if that car has been setting. I bet the gas is bad.

First I would remove your timing belt covers and check the timming marks. The car was not running when you bought it, The dummy probably didn't know what he was doing or he would have fixed it himself and got a extra $1200. So I would think he had the marks off.

There are marks on the cam gears you line up, and a mark on the crank pully you line up. It is so simple.

Check fuses,,.......... Then if it doesn't start.........Ground the #1 wire and spark plug to a valvecover bolt. Have a buddy try to start it. It should spark. The try the #2 plug & wire and see if it sparks. That way you check both coils.

I bet you are just a tooth or so off. Becareful when you tighten the tensioner. It is common for the belt to move enough to make it a tooth off.

If you are lined up and have spark. It may be fuel. (Or bad fuel!!!!!) Spray starter fluid into the breather and try to start it. If it start than you have a fuel issue.

after all is checked. Last thing to look at if all is good..........
Keep in mind, these car's are notorius for the ignition to cause starting problems. So don't keep whirling the motor just quick start and shut off, start and shut of over and over and it will usually sart on one of them.

My 90 one would actually do better with jumper cables hooked to kit. Weird huh. Yea it was changed fast. problem fixed. ( I doubt this is your problem. CHECK FACTORY TIMING MARKS AND SPRAY STARTER FLUID IN BREATHER)

Cpt_Slow

iTrader: (2)

Check the timing! This will tell you first off if the coil is sending juice to the plugs, and will give you a good idea if the timing belt was replaced properly. If everything checks out, I'd check the fuel pressure - the fuel lines are easy to get to.

Erotomania

I'll try all of that, Its possible the fuel is bad. I did turn the key on and off a good 5 or 6 times before even trying to turn it over to rebuild fuel pressure and maybe push out any air. I have a strong sneaky feeling its the belt. I'm just a little burned out from doing a full tear down and rebuild the last 2 nights working all day then starting on the car at 6p, to aboue 1 or 2 am for the last week!

I'll probably just pull the TB back off and put the crank on its mark then the cams on theirs and install it as if I was doing a new belt. Then see what happens and go through the other tests you guys have mentioned.

Sorry about the profile and sig stuff. I thought I had done the profile a few days ago but I guess not. I've been a wee bit on the busy side.

Thanks for all the help, I'll check back for any other suggestions and report the news after I give it another go!

Toddcod

iTrader: (8)

Sounds good.

I would still unhook the fuel line first, And spray starter fluid in the breather and try to start it.
It might save you ALOT work.

Remember when you try to start the car the afm has to be hooked up, you can't have the tube unhooked. It won't start if it is unhooked.

Good Luck!

Erotomania

So, just some pictures of the tear down. I checked over the whole car again, checked for ignition, that was good. Fuel i was still a little questionable on, tried the starter fluid thing, that was a negative. Then when checking around I moved the wire harness for the Airflow meter and heard the fuel pump cut on pretty strong and let go and it stopped. Then remembered a friend was trying to take the airbox off and had somehow decided it was a good idea to unscrew the afm's plug from the box and I found out today in the process of doing that he yanked all the connections lose from the circuit board. So I redid them, hopefully correct. Still wouldnt start. I also noticed after pulling the plugs there was a little pool of fuel sitting on top of the cylinders. So I left the plugs out and valve cover off for the night hoping that fuel will evaporate out.

In the pictures I tried to show the belt marks as best as possible. Where I think I really screwed up was, I marked the teeth, and sure enough replaced the belt on those teeth, but I remember now when i put the belt on the markings were placed on the most centered tooth on both cam, and when i reinstalled the cams they were not centered. So my cams are as you can see lined up together pretty well, but they are off my memory a good 5 or more teeth off from the original position on the crank.

Could I get the motor back to TDC by judging when the pistons are actually at TDC? Or should I just quit thinking lazy and just pull the crank pulley and line up the crank at its mark and then set the cams in the right place?

Toddcod

iTrader: (8)

It is best to find the mark. But if you have a long screwdriver, or long extension, you could turn the motor back and forth at top dead center, and find the exact top dead center......

Then look at your cam marks.

Are you using new plugs? Teh old ones may be fouled with water and oil too!

Erotomania

Yup, New NGK Vpower plugs, and new NGK plug wires. New oil and filter, just used straight water for the cooling for now, which probably is a bad idea now that I think about it if I need to be watching for headgasket leakage. Though, once the car does finally start I'm going to run it a short bit and then change all the fluids and when I dump the oil, any coolant or water should jet out first anyway so.

I think TDC is cylinders 1 and 4 at the top correct? I do have several long screw drivers and I've done this with a honda before. It worked but it was a little bit of a trick to make sure you have it hold and stay exactly at the very top. I may try it that way first. Its much more of a relief for me to know this motor wont bend valves if I'm off on the TB.

Toddcod

iTrader: (8)

Yep #1.

Good Luck!

-----------------------------------------------------------------------
LOL yep there is nothing as sexy as a grown man in a Prizm. LOL.


Some dude at the drag strip had one hooked up though. I was running 10psi and only pulled 3 1/2 car lengths in the 1/8th mile. He was white smoking tires and all.
I wounder if he had nos?

Erotomania

Its only sexy if you are driving a champagne colored one. Any other color and the effect is gone.

The 2001 and up Prizm is a toyota corolla with a different radio haha
The corolla of that generation shares the celica motor pretty much. Atleast that is my understanding. With a 5 speed the cars can be pretty quick, I haven't seen one boosted though, that would be pretty wild. I'm pimpin the 3 speed automatic


Thanks for the help, hopefully we'll see some results here in the next couple days..

lesson learned...Friends don't let Friends touch your miata, and timing belts don't play games.

Erotomania

Well, my screwdriver technique didnt work so well. It started up instantly, a lot of chatter from the valve train, lots of white smoke that smelled certainly like gas. I'm sure some of that is the pools of fuel sitting on the cylinders. The other part is im sure I'm still a tooth off. Tomorrow I'll pull the pulley off and set it to the marks and get it done right. Today was just a test to see will it indeed start. Only took an hour to redo the belt and fire it up today so, no biggy. It didnt seem to be mixing any fluids so I'm hoping the gasket holds. It holds a good idle on its own. Motor was a little jumpy at about 650rpms but I'm sure thats more a timing problem than anything. I'll probably idle it until running temp tomorrow then dump the fluids again and redo the timing belt(maybe replace it to hell why not?!) The valvetrain was very chattery and loud. I'm hoping it was getting oil well, the oil gauge(which i assume isnt every accurate?) showed good oil pressure, a little above halfway. I putted it around the parking lot of the shop, surprisingly ran okay minus the noise of the head and the leaking downpipe on the exhaust. Clutch seemed good and shifted gears just fine.

Long story short, It was pretty relieving to see this thing run. Seeing as I saved the car from being burried in a guys backyard covered in mud and grasses and got it knowing only it had a blown headgasket and wouldn't run. Hopefully I'll be able to report back by the end of the weekend that its runnin in tip top shape and ready for the goodies to add up!