Hi
I have owned a mazda rx7 series one for a while now and ever since i bought it i have had problems. when i back off it jerks backwards and forwards, maybe something to do with the carby? Any idea's

 

Be more specific about the car's actions. Too many variables to decipher what is going on without more information on the car's behavior.

 

It sounds like you're transmission is confused, and having an internal, emotional conflict. It may need some mental help. I'd see about getting it some therapy to help it decide which way it wants to go.

J/K........your description is a little vague, to say the least. I'm sure with more info we could help you out.

 

The car misfires during decceleration, but as soon as u engauge the clutch it stops jerking.
One of the blokes at a garage i went to said that is was an innerit problem with This type of RX-7 and most people put up with it. He seemed to think that their was to do with the vacuum system.
i don''t know how to clarify it any further

 

you mean when you let off the gas to deccel it jerks and when you push the clutch in it stops jerking??

 

Mine does the same thing, kinda.... During accel it is fine as long as there is positive pressure from the engine. I first thought that it might be the Ujoints, but it ended up being the rear end itself. Easy check though. Hope it's not the same for you, but this is a worst case senario.

 

"you mean when you let off the gas to deccel it jerks and when you push the clutch in it stops jerking??"
indeed

 

So, if you were in first gear and you reved it up near 7000rpm and lifted the throttle will it "jerk" right away? If not, at what rpm does it start if you were to let it coast in gear for a bit?

 

Sounds like classic shutter valve failure. Plug it off in the air box and see how it works out. I don't have a pic right here but a quick search should answer all questions

 

Yep, search shutter valve mate its an easy fix.

 

^+1

 

I had the same problem until I did the RNR... Now its pretty smooth.

 

problem= under part throttle or engine deceleration at low rpm/low load it bucks like its having an orgasm

solution= re-rout all emission equipment to the trash

if you need to keep the emission equip, check for cracks in all the hoses(an UNLIT propane torch works well here). your dealing with 20+ year old rubber.

isaac

 

you could be driving at too low of rpm's, try to keep the rpms at least above 2,500 when cruising.

 

Yah, I have seen many older cars do this. It could be the shutter valve, but I am willing to bet it could also probably just a combination of the old worn out componants, not actually a problem with your carb or engine.

I used to have similar symptoms in my old GSL, and even after installing a newer carb and fixing any vacuum leaks it was still jerky. As soon as my rebuilt differential went in, the problem was much better but still noticiable. My guess is it that the driveshaft and transmission were just getting tired as well on me.

Decelerating in gear at a low rpm excentuates such slack in your driveline, and shows itself with the jerky motion, which is the play in everything deciding whether the wheels or the engine is gonna slow down faster, since the parts arent as tight as everything originally was.
The engine/transmission mounts are another thing to look at, in severe cases these could be contributing factors as well.

Keep up the RPMs higher as said above should feel nicer, our cars dont mind a little revving.

Let us know what works for ya!

 

sorry it took me so long to reply.... haven't looked as of yet, i am so bloody busy

 

does anyone have any pictures of where the valve is located, or a link to a page that does.
As i have no idea where it is

Is this for 1979 series 1 RX7's