Force Fed

I have this '87 N/A that's I'm trying to fix for my dad so he can sell it. The guy he got it from said these problems started after he lent the car to a family member, who decided to return the favor by having the oil changed for him. Apparently the car had always had synthetic in it since (original owner I believe), but the place the relative took it to replaced it w/ regular. Right after that is when they started have problems w/ it and sold it to us.

Here's what it's doing. When we first got it, it was hard to start, finally got it started and it ran decent, but smoked like crazy, smelled like old fuel and oil. Then couldn't get it started again. So Dad brought it up to my house to work on it. Took the plugs out, pulled the EGI fuse, put ATF in the chambers, spun it over, put a little more in, stuck the plugs back in and the EGI fuse. Tried a bit, would almost catch but just couldn't catch. Put fresh gas in it. No change. Pulled the plugs and fuse again, spun it over to clear the fuel, put more ATF in it and let it sit overnight.

Next day, stuck the plugs back in and the fuse, spun it over and it fired right up, cleared out the olf fuel and ATF, and ran pretty good, little rich but most importantly, no huge cloud of smoke, just a little fuel smoke. Stopped and started the engine quite a few times, was the same every time, little rich but no major smoke. Has great power, feels like a brand new engine, runs smooth, spins tires easily.

fast forward a couple weeks, been parked out back w/o running the whole time. Get in it and crank it up, fires up, then immediately develops a miss, like a plug fouled out, then here comes the smoke again. WTF?? Shut it off, crank it again, same thing, still missing and smoking. As in, I thought the fire dept was gonna show up lol, it literally looked like I had a big fire in the backyard.

Now, as I said, the previous owner said it started this after the oil was switched from synthetic to regular. Is there any way this could cause this problem, or is it just coincidence? I was thinking maybe the OMP is screwing up and dumping oil in at any throttle postion, it is a lot worse the more you open it up. If I just hold the revs at around 1k-2k the smoke isn't as bad.

Sorry for the long post, but I'm kinda baffled as to how it runs bad and smokes one day, then doesn't, then does Only thing I could think of was the OMP or related parts (oil injectors or something). When it runs good, it runs GOOD!

Spectator

iTrader: (1)

Its a coincidence.

What color is the smoke? Blue, white or black?

Force Fed

Thick whitish smoke, tint of blue maybe. I thought maybe coolant leak but doesn't smell like it and it's full of water still. Also there's none on the plugs. I'm gonna try it again here in a bit, maybe I can get a pic. Gonna pull the plugs again too and check them.

Spectator

iTrader: (1)

I would guess its a coolant seal issue. Just to be sure, remove the radiator cap, start the car and check for bubbles. If you have some, then you have a coolant leak.

kontakt

Well in order to get smoke something has to burn. You've pretty much got to be burning Oil, Coolant, excessive Fuel, or your catalytic converter. If your oil and coolant are fine, then maybe your injectors are sticking open sometimes and just dumping fuel into the engine. If half of the engine was flooding as it ran it'd probably run pretty bad and dump smoke. If your cat is clogged or otherwise damaged it can smoke something fierce, and the backpressure can make the car run like crap... but that wouldn't really be intermittent.

clokker

iTrader: (2)

Not that it matters, but I think this is unlikely to be true.
Mazda wasn't recommending synthetic oils in 1987 (not to mention they were still very expensive back then) and even now it's a hotly debated issue, so it would have been a brave new owner to make such a decision.

Anyways, I too think the oil change is just a red herring.

Why not perform a 60k service and see what happens- it won't hurt and the new owner will be grateful.

HAILERS

Not the omp in any way.

Do the *TEd THING*. After fully warming the engine up, rev the engine to five/six grand and hold it there. If it's bad oil control rings, it will start smoking as you hold the rev's to six grand.

Force Fed

Here's a pic of the smoke, it's greyish blue actually. Coolant is still full, and there's no pressure coming out of the system w/ the cap off.

Force Fed

Here's a vid, a bit skippy (cam sucks for video) but you get the idea.

HAILERS

Bad oil control rings on the rotors in my very humble opinion.

Aaron Cake

iTrader: (1)

Looks like oil smoke to me. Coolant smoke is more visibly like steam (since it is, of course). The metering oil pump will never cause that much smoke so it's likely bad oil o-rings.

Force Fed

Okay, so basically the engine has to come out to fix it properly? The oil control rings can be intermittently dysfunctional, so to speak?

Aaron Cake

iTrader: (1)

The engine must be disassembled to repair it. The rings can leak at low RPM but not high (rare), all RPM ranges, only high RPM ranges, etc. depending on wear. Sometimes they can tear which results in a random leak...

Omixeo

iTrader: (1)

It seems that I'm having this problem as well. Giant billowing clouds of blue smoke coming out the exhaust at low rpm's while the engine is cold. And I keep getting a random check engine light that goes away by itself. I haven't checked codes yet but I'm thinking it'll come back as the OMP. Is there any way for there to be too much oil injected into the combustion chamber that would cause this much smoke? I just don't want to believe its the oil control rings. This problem came out of no where within the last week, I don't know if its possible for the rings to get that bad that quick without me intentionally flooring it while the car is cold.

Aaron Cake

iTrader: (1)

The metering oil pump is just not capable of moving enough oil to cause that much smoke.

Pandemoniac

iTrader: (1)

bout time I make my 1st post and this is a good thead.

Force Fed had a '90 FC n/a that I had bought for him. Originally wouldn't start, but now it just acts the same as his red one. (maybe 6-ports hate him)
Other than being super difficult to start then cold, if this smoking was taken care of it would run pretty good. Once it warms up it idles fine but the sheer volume of smoke when you get on it starts to make the engine bog.

Originally the engine only smoked when cold, and i took it for a few test drives and ran like a champ! The problem actually got worse AFTER I did the tranny fluid trick, it ran fine the day after, then started it up after a week and it just belches clouds of death ever since.

Would it be realistic and possible to disassemble the engine, change out the oil seals and expect it to run well? How much money would I be looking at? I'd be doing all my own work except for any machine work, if needed on the irons for the new oil rings to seal. If the irons do have to be milled are new side seals 100% neccessary for it to run worth a damn at all?

Aaron Cake

iTrader: (1)

Sounds like a classic oil o-ring failure. The corrosive nature of ATF on the rubber was the nail in it's coffin.

You could open the engine and just use a "soft" gasket kit (oil rings, coolant rings, other misc gaskets) to refurbish the engine but it's crazy at that point not to also replace the apex seals. Irons don't need to be lapped unless they are out of spec. Even if they are a little out of spec you don't need to flatten them if you are on a budget. And for your first rebuild, reusing side seals (which hardly wear at all) is actually a better decision then to screw up clearancing a set of new ones. Just make sure to put all seals back in the position you pulled them from, and CLEAN.

Pandemoniac

iTrader: (1)

Ok, the only thing that's thrown me off is the real high price I've seen for the engine rebuild kits at around $1100+ So for a "soft" gasket kit and apex seals, how much would I be looking at spending? I apologize for the newb question but I tried searching.

Pandemoniac

iTrader: (1)

I finally tried playing with my car again after a long time. Took absolutely forever to get it started again with the help of a bunch of starting fluid, I needed to jumper the fuel pump connector to make it run at all on gas.
Things have changed since last time, now I get very little smoke and on a test drive it ran very well. There is some smoke at idle, but it is light and bearable. An occasional small puff exists when I was driving but it wound it's way to 8 grand fine and feels strong.
What gives? Do bad oil control rings randomly work well and then not, or is there actually hope that I may not have to buy a $900 rebuild kit to make it run fine? I'm just afraid it'll somehow go back to belching massive clouds and misfiring past 4500 or so again.

If I do have to crack this engine open, the amount I've seen for a rebuild kit is the most rediculous of any engine I've seen. Any tips to saving money and still have a reliable engine? I'm not trying to build a race car right now.

RETed

Oh?
Have you ever priced out a rebuild kit for another Japanese car (even though it's piston)?
I just paid over $100 for a ******' Toyota 7M headgasket...

About $1,000 for ALL NEW MAZDA OEM PARTS isn't so bad after all.

This isn't some domestic Chevy aftermarket rebuild kit...


-Ted

Pandemoniac

iTrader: (1)

Guess not, my main project car is an '89 Dodge shadow with a rurbo 2.5l 4cyl, a gasket & seal kit is about $75, rings & bearings added to that would run me a little over $200 total. For the price to refresh this engine I was able to add nearly 100 hp to my shadow, needless to say it'll wipe the floor with my Rx7 and a stock tII I ran across.

Aaanyways, my point here isn't to bitch. I've always been facinated by the little mazdas and I was lucky enough to score this overall pretty solid car for really cheap. Based on the symptoms I've written above, is there a chance anything else could have been to blame other then the oil seals? I'm just hoping there's a chance that it may perform alright for me for a while. When I have enough money (I'm broke until I get settled in the Air Force) I'd love to toy with this and get it built right.