hcaulfield57

iTrader: (1)

Hi all. I went with my father to test drive an 83' GS today. I drove the car first and quite liked it. It felt very nimble and quick, but I did stall it like four times Not exactly sure why, but I did notice that it needs ALOT of revs to get it moving, but it felt pretty fast once above around 4k or so on the tachometer.

My father subsequently drove the car and couldn't get it into gear. Well the car has like 50k miles on it, but it looks like the owner hasn't driven it much lately. So something is screwed up with the clutch or clutch fluid or something. The brake light was on the whole time which apparently means it needs more brake fluid?

Anyways, I'm going to see if I can get the owner have a shop look at it. Anyone have any ideas if this seems major and I should walk away, or something that's fixable? Sorry I know I haven't given much information, but the car seemed fine when I was driving it, besides how easy it was to stall, but I think that's probably a result of the lack of torque, not an actual problem...

Mods - I hope this is an appropriate thread, let me know if it needs modification.

Cookboy

iTrader: (10)

Probably clutch master and or slave cylinder(s). Relatively cheap and very easy repair.

KansasCityREPU

iTrader: (9)

I'd be concerned with it taking a lot of revs to get going. Could be the clutch or a rotor going out. What is the idle RPM? If you figure out the shifting issue, maybe the high revs will fix itself.

hcaulfield57

iTrader: (1)

I don't recall exactly where it idled, I think it was a bit under 1k rpm. It felt like it had little to no power below 4k, but seemed pretty peppy in the higher rpms. I think I kept stalling it because the clutch kept engaging at an inconsistent place, but I dunno. Seemed like the car had definitely sat for awhile. I'm okay with fixing things, but I don't want to have something major let go right after purchasing it.

The brakes had a very low pedal engagement point, and the transmission felt a bit notchy. I wonder if this is just a need to replacing all the fluids, which isn't too big of a deal. I was amazed with how smooth the engine revved though, feels like your pootling along, but tachometer reads 5k.

erick31876

iTrader: (8)

Maybe the rear calipers are hanging up, I recently had that same high rev problem to get going on the 85 GSL I just got that was sitting for a while, the right rear caliper was hanging up Really bad.

KansasCityREPU

iTrader: (9)

Do a compression test before buying.

hcaulfield57

iTrader: (1)

A compression test is a good idea. The owner seems willing to have the car looked at by a mechanic, but doesn't seem to want to take it down to my neck of the woods (about 45 minutes away), I know there's a Mazda dealer in that town, maybe have them look at it, or no? I heard to stay away from Mazda dealers, but I dunno how relevant that is.

But yea, I think I've got to have someone look at it before buying. I really did enjoy the car, but it'd be a shame to buy a paperweight.

LongDuck

An 83 GS is now 32 years old - and probably older than you by a longshot. Recognize that these cars had 101hp which torque peaked at over 4k RPM, so if you're used to driving piston engines - it's an entirely different driving experience.

On the clutch engagement, my experience has been that it's either working - or not working (i.e., pedal to the floor and no return). If the clutch is engaging at all, it's probably fine and just takes some getting used to. Brakes on the other hand, will tend to drop in efficiency over time, especially if they've been neglected.

I wouldn't write this car off just yet, but recognize that a car of this age is geared toward enthusiasts (pun) vs. a daily driver for someone needing transportation. The SA/FB can be rebuilt and restored to a point to be very reliable, but most cars haven't been treated well to allow this when changing hands. Good luck,

hcaulfield57

iTrader: (1)

Yea the car is much older than me. I spoke with a shop that works with rotaries in my area, so I'm going to try and see if the owner wants to have them take a look. We'll see what happens.

Owner of shop told me that 12a parts are no longer produced, which I didn't realize for some reason, not sure I'd want to swap a 13b into the car, I know that it would make more power and torque, but was really hoping for a carb'd 12a. Kind of would want things original...

Jeff20B

iTrader: (13)

You can still get good used 12A parts like rotor housings etc. I wouldn't worry about it. You just need to put a want to buy add in the FS/WTB section of the forum in the appropriate subforum for 1st gens. However because the engine does in fact run, I wouldn't worry about it.

Oh and as for how much you have to rev it to get it going, it might have a light aftermarket flywheel and a port job. Sounds pretty typical for only having any real power above 4k. Then again like LongDuck said, if you are only used to modern EFI piston engines, which have a lot of tip-in these days, suddenly driving a 30 plus year old 12A that we can only guess how it's currently set up, it is going to be a different experience. Especially if it was ported too big for the intended driving style (the street) and if the flywheel is too light (like aftermarket aluminum which I don't like very much).

Or lastly if it's just got a stock Nikki on it, those are known to be gutless in their stock form, what with tiny little 20mm primary venturis and vacuum secondaries with giant air bleeds etc. Mazda did it this way to save gas and still meet emissions requirements. However these days some 30 years after these particular models came out, we know how to make the Nikki perform better and with a lot more power (lots of low end torque and high end power with a fat midrange) than the usual replacement carbs like Holleys and stuff. These days, I wouldn't even look at those ancient 1950s designed carbs. I'd stick with a properly modified Nikki which allows you to corner and have fun in an autocross where as a Holley simply can't due to fuel flooding and starvation issues under any kind of g-forces during cornering etc. This is due to the way the carb must be mounted to the manifold to work with the rotary's intake ports I.E. the middle iron (intermediate plate) has primary runners and the two outer irons have the secondaries. Thus the carb must be installed rotated 90 degrees from how it was intended to be installed on a V8. This leads to issues as I'm sure you can understand.

There is a whole lot more to mention just on carbs alone but you get the general idea. I hope this was helpful.

hcaulfield57

iTrader: (1)

Yes this was helpful, I'm glad to know that there are still options for 12a engines. Regarding the lack of low end power, I believe the engine was completely stock along with the flywheel and carb. The owner said the tune on the carb probably wasn't very good, so maybe that's the issue. It idled smoothly, but there was little to no power down low. Upper revs felt great. I think it's likely just I've never driven a car like this. I <i>did</i> like the engine, so I'm totally not complaining, just don't know if something is wrong or not. Regardless, we'll see.

TimWilbers

iTrader: (1)

On dry days my 84 12a is my daily driver. All stock with unmodified Nikki.
I typically run between 3500 and 5500 on city streets.
Lower RPMs are only for stopping and getting up to 3500.

Does that sound familiar?