the car:

I own a 1987 SE, manual tranny.
Ive previously owned a RX7, but this particular car ive only had for a couple months, it is a second car, not daily driven. Ive given it a full tune up and inspection at a reputable shop. it seems to be in good working order other than the oil pressure reading high, and occasionally its fussy to start but always eventually does.

So far as a list of modifications all i have done to the vehicle is suspension work, wheels, and exhaust from the manifold back. The main catalytic converter is new, but the others are hollowed because i could not find an availiable replacement for them at the time. The motor currently remains untouched.


Heres the problem:

During good weather conditions I took my car out for a spirited drive on some backroads.
While pushing the car through a turn i noticed it behaving oddly. The car was stumbling as if the rear tires were momentarily loosing traction, perhaps on the reflectors that mark the center of the road, but this was not the case. The best i can describe the feeling is its similar to accelerating fairly quick from an intersection in wet conditions and when the drive wheels hit the paint that marks the crosswalk the tires slip, but then regain traction once theyre off the painted surface.
Thats exactly what it felt like, except it was in a turn and the road wasnt wet, my tires werent slipping yet the car stuttered several times.

I kept on driving, into another turn i noticed it again. This time it struck me as odd. My first guess was lack of fuel pressure, however a quick look at my needle indicated plenty of fuel in the tank.

I pressed on this time trying to instigate the problem so that i could diagnose it. I pushed into a turn heavy on the throttle, i noticed the tachometer jump from approx 4k to 6kish, then suddenly drop as if the vehicle was at idle, then suddenly regain itself to actual engine speed.

I slowed down, unsure of what exactly was happening and gently drove my car back home.

I havent driven the car much after that. I drove the car the other day and accelerated quickly in a straight line, without a problem. I havent gotten a chance to duplicate the conditions that caused the stuttering problem.

Heres a little more info:

The week before this happened, i had let a friend drive my car. Other than generally driving as if she had forgotten how to drive a manual; She made a mistake and placed the shifter into second and let the clutch out too soon, the engine speed went soaring past redline. Needless to say she'll never drive my car again.

Being that this car is on the factory clutch and flywheel (which i am surprised is still in tact) the clutch seems to be in borderline fair/poor condition.

in conclusion:

Im hoping it was the clutch that is contributing to the slipping/stuttering feeling i experienced and not a fuel pressure problem, or worse some motor damage from letting my ex-girlfriend drive the car.

I would appreciate your feedback on this, do you think it could be the clutch or something else?
any suggestions will be greatly appreciated, i thank you in advance for your time and responses.

-Diavolo


p.s. also if you guys could answer one more thing:
what oil do you guys recommend? (s4 13b non-turbo) i usually use kendall, but the only place near me that used to stock it no longer carries it. i think im gonna have to switch brands, im open to suggestions.

 

just out of curiousity, how much gas was in it. mine was cutting out like that with ~1/4 of a tank. that would explain the tach and the jittery feeling. you engine cut out due to starvation and then caught because you were basically roll starting it. a clutch wouldn't bog the tach, just slip and the rpm would raise.

as for oil i use castrol gtx 20w-50 summer and 10w-30 winter.

 

i think i had somewhere around a half a tank of fuel, could it still be possible the fuel was being pulled away from the pick up? I was cornering hard.
Also could that cause the tachometer to surge?

 

sounds like slipping clutch
don't think you're friend did any damage unless she sent it past like 8500 - just depends, i guess

 

8.5k ....ya thats why i said im surprised the stock flywheel is still in one piece.


Im glad to hear it was probably only the clutch, or fuel being sloshed away from the pick up, anyone else have any theories?

 

the clutch would never bog the tach. it can cause it to rise and maybe dip a little. its called physics. dropping to almost idle means that the engine almost stopped. i don't see the clutch being able to cause that.

for flywheel failure you would need a decently continous 10k. i'm not saying a sudden burst of roughly 8.5k letting it loose. maybe your worn clutch.

 

thanx everyone for the replies so far. I'm still looking for other suggestions or re-enforcement of the existing opinions.

-Diavolo