JIMMY54

iTrader: (2)

Really weird thing happened I was approching redline in 4th, when everything just cuts out. I thought I had blown the engine but the engine was still running and I quickly put it in neutral and put it in 4th again and everything was fine as long as I didn't approch redline. So I tried it again on my way home and same thing happened. I have a new clutch so I'm thinking what the hell? Can it be that the tranny can not handle it? I was running nos "race-only" additive at the time (for the first time), if that helps cause I've gone to redline in 4th many times and that never happened to me b4. The engine is running super strong at the momment (13B). Other than that the car runs fine. I just filled the tank with clean 93octane and no additive just to see if it makes a difference.

Mods to engine:
MSD BLASTER 2 COILS
PACESETTER HEADER
COMPLETE 2 1/4" EXHAUST
REBUILT MOTOR (DEALERSHIP)
HKS/VIBRANT INTAKE SYSTEM
2ND GEN PLUGS
VACUUM HOSE REPLACMENT
DYNAPACK SPORT CLUTCH
BMC RACE WIRES (SOLID CABLE)

SilverRocket

I had a similar problem - one of my trailing plugs had broken and was causing misfire/detonation at high load. I'd say the first thing you should do is look at your plugs.

Maybe you should clarify for everyone what you mean by 'cutting out'? Do you hear any noises like possibly detonation, is it smooth or rough, does your car shake at all, does it hold at 170 or does it lose speed?

JIMMY54

iTrader: (2)

Andrew how've you been? Hope things are back on track with your car!! As for mine the plugs were just checked now and they are absolutely perfect. AT 170kph there is alot of vibration but thats from the driveshaft. The engine doesn't get effected at all, the revs are stable the whole time. I just feels like you put the car in neutral. but it isn't. The second time I did it, I put in fifth and the revs went to 5000rpm and it was having trouble accelerating passed that point as if the cluch wasn't gripping enough to increase speed, just gripping enough to maintain the speed I was at. At this point I was doing 180kph (open highway-no cars around... I ain't a maniac) I didn't push the car in fifth very long incase my clutch was getting destroyed. The thing is the engine wasn't lacking any power. The car pulls great.
1st gear 40kph
2nd can't remember
3rd 125kph
4th 170-180kph
5th unknown.... (not even interested)

Reason this is bothering me is that 3rd and 4th gears are my favorite cause I do alot of highway driving and I love that feeling of fast acceleration when you are already doing over 100. I don't think that there is a cure for this that won't be expensive but I do worry that when I keep adding perfomance parts that this problem will hit even sooner than redline.

Anybody know if a second gen tranny is stronger or have better ratio's for this car. I love the gearbox setup of this car but I was told that it can't handle over 150hp. Everybody talks about a TII transmission but thats only if you are running a TII motor. Nobody talks about just adding a second gen transmission of a N/A model. As my car gets stronger I believe that I'm gonna keep my eyes open for one in the scrap yards. As for my clutch I kinda regret not getting that center force II clutch. It's gotta be one of the 2: tranny or clutch.

P.S. That NOS $30 dollar "race only" additive doesn't seem to be worth the money. 104+ octane boost (black bottle) works better in my opinion, for half the price. And they have the same octane increase which is 7 octanes.

P.P.S. adding a tiny bit of octane boost to your lawn mower does wonders, long thick grass watch out no more stalling when you go over those thick patches. Be careful no to add to much cause my friend blew the engine on his. He said that engine was screaming and was wicked for about 20 minutes then it went. 2 cap fulls is enough to a full tank. My friend put like 1/3 octane boost when his mower blew.

SilverRocket

Hey Jimmy, my car's great!! I thought it was messed up last week, but my secondaries were just stuck partially open. 2 seconds to fix. I've also been whining about oil filler neck condensation, which is a byproduct of taking out all my emmissions gear. But I fixed it today.

I love the tip about the lawnmowers, gotta pass that on to my dad!! I don't live anywhere where I have to cut the lawn anymore

We had another big meet last Saturday, did you see the posts on the Canadian forum? We hit 210 on the 404 for a bit

I don't know too much about SE's, but here's a couple thoughts.

I really doubt it's anything to do with your tranny. When your clutch can't handle it, it starts slipping. What happens is the revs go up a lot faster than you're accelerating. If this isn't happening, I believe your clutch is not the problem.

I don't think you need high octane for an NA rotary, everything I've heard tells me rotaries run better with low octane. I had my timing advance very hardcore for a while, and 87 octane was still fine. But if it works on your car, that's all that matters.

So do you think it's ignition or fuel? Remember that 4th or 5th at full throttle is very high load for your ignition system, so that's where you would notice a problem. Have you double checked every part of your ignition system? I'd say your coils are the likely culprit, is it possible your MSD's are shot?

Past that, what about your fuel pump? Have you replaced your fuel filter anytime recently? Could your injectors be clogged or something? I'm sure there's lots more FI stuff that you know much better than me about.

My main advice is to check out all the basics before launching into the complicated stuff. I always do the hard stuff first, then find out it was something simple.

PS - Did you get your rear wrap-around installed yet?

smnc

Well, I don't see how a tranmission can slip normally. If you try to put too much power through one, it might let go altogether but I don't see how it would 'cut-out' and then work again afterwards, unless it's been driven to the point where the teeth on the gears themselves are worn out. (This happened to my uncles 1977 VW Rabbit a couple years back).

Either your transmission is garbage, or your clutch is slipping at high revs. But if your engine is NA then I don't see how this is so with a new clutch.

Maybe get your transy checked at a reputable shop.

The other thing that puzzles me is why you're running high octane in an NA engine? Rotaries generally run better with an 87 or 89 octane fuel (in the NA motors). I don't see how your engine would run better. Then again, if it works...

-Spencer

JIMMY54

iTrader: (2)

My MSD coils are a year old, so they should be fine, I'll double check them anyways today. Fuel filter was changed last year and it has about 20,000kms on it. Fuel pressure regulator was changed when I got my injectors professionally cleaned and adjusted. That was in the beginning of summer. My clutch is 3 months old at the most. Spencer....My Tranny has 262,000 kms on it. Chances are it may be wearing out just like you mentioned about that 1977 VW Rabbit. I have a feeling that it must be gears. But when the tranny comes out the clutch will be exposed and it will definitly looked at. Tranny work is never cheap. Luckily my father has a car hoist. Tranny can be removed in less than an hour. And they are soo light. I can lift it over my head easily. (without oiL) LOL

I run high octane all the time, I notice less engine vibration with it. It runs smoothest with the octane additive. I'll try out 87 octane next fill up.

Andrew you guys hit 210 on the 404!! That must have been wicked!! I don't have those kind of guts. LOL!! Too bad I missed that meet. I haven't been on the forum for awhile. Then I ended up hooking up with a girl from T.O. and the car has been put on hold for awhile. And this happened on the way to her house. As for the wrap around bumper for the rear I DID IT!! It just has to be professionally painted, It is painted it blue and it just needs some slight buffing. As soon as I finish that roll of film I'll put it up. The car finally looks nice from the rear. Maybe even better than the front. If you like the bumper it takes about 1 day of work to do it. Using mine as a guide it will take alot less time and it will probably turn out even better. And Silver isn't hard to color match. So where are you staying now? Still in T.O. if you want we can cruz sometime. There are so many places that look like car shows around here. We can get pd_day and his friends in on this.

P.S. Thanks alot guys for your ideas and help with my 7.

peejay

Uh, can you say "long overdue"? Although I'd think an EFI car would act up differently from a carbureted car... with a carb and a plugged filter the engine will suck the carb bowls dry and the engine will cut out hard, but with EFI what typically happens is the car just leans out at high RPM for lack of fuel, it's not all-of-a-sudden. Ya never know, though.

Say, did your tach stop working momentarily when it cut out?

Keep in mind that when a tranny jumps out of gear, you're instantly in Neutral, so it's not like the engine cuts out, but like you stepped on the clutch. If that's what happened, believe it or not, tranny jumping out of 4th gear or hard to shift into 4th gear is usually caused by misalignment between the transmission and the engine. If the E-shaft and the tranny's input shaft aren't lined up with each other, the input shaft will get cockeyed in the transmission. 4th gear isn't a "gear", it's just directly connecting the input shaft to the outpust shaft. Input shaft cockeyed = 4th "gear" can't engage fully = can pop out. Usually this is caused by mechanics driving out the engine to transmission dowels and not putting them back in, although sometimes tolerances this way and that cause even brand-new parts to fall out of concentricity.


You should be running 87, or 86 if you can find it. Mazda used to run 80 octane in their race N/A engines. Any higher octane is just power thrown out the exhaust pipe. It probably runs smoother because it's not burning as quickly as it should, like when "soft-pedaling" a bicycle.

JIMMY54

iTrader: (2)

Peejay, The tach was working the whole time. I have an air/fuel ratio meter and at high revs the guage is always in the rich zone. You're right about that fuel filter, it is time to get that changed. Whoops!! I thought you didn't have to change them until alot longer.

I'll be getting that filter today... Thanks man! As for the octane I'll be trying to find the lowest octane... Damn I've been paying 80 cents a litre. Thats $55 bucks every fill up. Times that by 2 each week..... Damn!!

The 1984 owners manual says
**fuel filter change at 48,000 kms
**Use at least 91 research octane

I'll change that filter and try the cheap gas and see what happens, I'll keep you posted. And I just remembered I filled up last night with 93. I'm off to the parts store for that filter. I remember it was huge.

Thanks Bro

peejay

91 Research octane is 87 (R + M)/2 octane. FWIW.

JIMMY54

iTrader: (2)

87 it is! what does the rest mean? you got algebra going on... LOL

smnc

Octane is basically a pre-detonation resistance measurement. In North America we use the AKI (Anti-Knock Index) scale. It is composed of two different ratings.

The Research Octane Number (RON) and the Motor Octane Number (MON). RON is the fuel's measured resistance to detonation during normal operating conditions and MON is the detonation resistance during heavy use.

The Formula to figure out the AKI of a fuel is:
(Motor Octane Rating + Research Octane Rating) / 2
(M + R) /2 = AKI

If your Fuel has a RON of 91 and a MON of 83, then the AKI is 87.

Try 87 octane fuel witha high quality fuel additive like Lucas Fuel Treatment and/or MMO.

Anyways, it sounds to me like your trany is a possibilty, as you said your engine was unaffected. If it was your fuel or ignition system you'd probably notice the engine stumbling.

Quote:

Keep in mind that when a tranny jumps out of gear, you're instantly in Neutral, so it's not like the engine cuts out, but like you stepped on the clutch. If that's what happened, believe it or not, tranny jumping out of 4th gear or hard to shift into 4th gear is usually caused by misalignment between the transmission and the engine. If the E-shaft and the tranny's input shaft aren't lined up with each other, the input shaft will get cockeyed in the transmission. 4th gear isn't a "gear", it's just directly connecting the input shaft to the outpust shaft. Input shaft cockeyed = 4th "gear" can't engage fully = can pop out. Usually this is caused by mechanics driving out the engine to transmission dowels and not putting them back in, although sometimes tolerances this way and that cause even brand-new parts to fall out of concentricity.

Missalignment is certainly a possibillity, but even the 1:1 ratio in 4th uses gears. Four of them to be exact. It simply uses gears matched to maintain the 1:1 ratio. Read this for more info on how a manual trany works.
It's not actually the shaft that pops out (as all the shafts and gears are fixed, it's the dog-teeth in the shifter collar. Does the shifter jump out of gear?

My uncle's VW started similar to JIMMY54's rex, where the trany only slipped at high revs in the higher gears. It steadily got worse until the gears gave out all together. His car had just over 325k on it when the trany died, so a 264k RX-7 is possible although, manual trany's don't die that often.

JIMMY54

iTrader: (2)

Thanks for the gasoline explaination. As for the tranny, the previous owner used to race the car. The car was in bad shape when I got it. Mechanically and body wise. Since I've had the car just about everything was replaced or looked after very carefully. That transmission has seen much abuse, under normal driving it seems fine but really I shouldn't push the car as hard as I do. Thinking back that transmission is the the only major part I haven't replaced. I do change the oil frequently in the tranny and always put in that LUCAS oil treatment which I believe has kept it running this well. And car now is maintained like it was a Porsche. I kinda see the financal errors I make by pouring this amount of money, and this time spent on doing everything properly on an old vehicle but, this car is something that keeps us on our toes. Not only is it fun to drive but you have to solve certain puzzles in order to drive it again. These cars play games with us and once we started playing the games its too late to turn around. I think thats why we are all driving these earily 80's cars. And it would be hard to trade them for something alot newer.

www.portugesethug.homestead.com/jim.html

peejay

Normally I'd nitpick this (what is pre-detonation?) but this bugs me...

No, it DOESN'T use gears. Yes, there is the input shaft gear driving the countershaft gears driving the output shaft gears, for 1st, 2nd, and 5th gears. (Reverse has an idler, but anyway...)

4th gear does NOT use any gears. Pull apart a Mazda tranny, or for that matter ANY rear wheel drive tranny. (Besides 3-speeds and 5-speeds where 5ths is 1:1, of course) 4th gear is a direct connection between the output shaft and the imput shaft, so that no power is transmitted through the countershaft. Yes, all of the gears will be spinning, but that's how synchronized trannies work.

3rd and 4th gear share a shift fork, 3rd is the closest to the front of the trans. All sliders for the forward gears are on the output shaft. When you move the shift lever, you move the shift rod in the opposite direction... meaning hand goes forward, shift rod goes back. Shift up into 3rd and you pull the shift rod backwards, pulling the shift rail and fork, and the synchro slider, backwards, engaging 3rd gear. When you then pull the lever backwards, you move the rod/rail/fork/slider forwards.... but there is no gear pair forward of 3rd gear, the only thing there is the input shaft! The slider locks the output shaft TO the input shaft.

This way, there is a LOT less parasitic power loss... both in 4th gear because you're not sending power through 2 pairs of gears and putting side loads on the shafts and their bearings, and in all gears because there isn't a redundant gear pair to drive. Why bother with another pair of gears and all that hassle when you can make it lighter, simpler, more efficient, and cheaper by simply locking the shafts together for 1:1?

Note that most transaxles (FWDs, VW Beetles, etc.) do not have a 1:1 gear... that's because the input and output shafts aren't concentric (usually the counter shaft IS the output shaft) so you can't just lock them together. Freed of that, the designers can choose any gear they want for 4th, so they don't have to choose a final drive ratio based on where they want to put 4th gear and then change all the other gears to suit.

I have a gutted 12A trans SOMEWHERE around here, otherwise I'd have just taken a pic of it.

smnc

Thanks for the enlightenment. That's defferent than what I was taught, but seing as I've only ever disected one tranny (and it was an auto), I'll take your word for it. I understand the theory behind manual tranys, but I'd never heard about 4th being a direct connection (then again, my high school auto techer was an idiot). Makes sense tho. Thank you.

As for the pre-detonation thing, it was late when I wrote that, so cut me a little slack, eh?

peejay

Sorry for the blow-up, man... the whole losing my job/being sued by a doctor because the insurance company refuses to pay and I can't afford $2500 even WITH a job/just f'ed up my tranny/discovered that the rear floor gets SOAKED when driving in the rain situation has me a bit uptight lately.

uh, anybody wanna buy an FC?

JIMMY54

iTrader: (2)

More news on the car, jacked the car up and rear end is perfect. But the bottom of the car is soaked full of oil. I'm gonna check the oil level of the tranny. Somethings up. Funny cause the drive shaft is clean but everything else is clovered in oil. WTF engine is dry and topped up just as the rear end. I couldn't reach the tranny today but we'll see on saturday when the car goes on the hoist. Both rubber seals on each end of the driveshaft were replaced so have to find where this oil comes from. I wished tranny oil had a different color oil than the rear end. And motor oil be another color so leaks could be easily identified. Engine oil and multigear oil look the same!!

peejay

Hey wow, another advantage for Redline gear oil. It's almost as red as ATF.

smnc

No prob peejay, we all have bad days (or weeks or months).

great white north

Cutting out? Could be plugged exhaust. Need a vacuum gauge to check properly. Get a friend to rev your car and see if a "ton" of exhaust comes out the tail pipe. My '85 SE cats plugged, felt like I was pulling a trailer.

JIMMY54

iTrader: (2)

May cat's are fine, the exhaust was removed 2 weeks ago. I wanted the system lifted abit to allow more clearance over speed bumps and driveways. Thanks though.

JIMMY54

iTrader: (2)

Ha!!!!

Underbody covered in oil, the transmission seal were the driveshaft hooks up too, is leaking big time. Tranny was bone dry and that seal was replaced a month ago to be exact. Car going back to the shop. No damage to the tranny hopefully. Something could have mommentary popped out of position.

smnc

Well then, that could explain it!

Hopefully that will fix it. Good luck!