I was reading about the deceleration system which is PART of the ACV. Now the job of deceleration system is to prevent bucking/fuel cut when you let off the gas at higher rpms...now my CAR does exactly that, bucks, fuel cuts at high rpms when I LET off the gas! Now I got my AIRPUMP out right now and was wondering I put it back and got the ACV running back to normal again, whether this might SOLVE my problem?

 

There are a number of pieces to the deceleration system.The piece described in the manual is basically the anti afterburn valve in the ACV which lets air in to stop popping and banging in the exhaust.
In addition the ecu reduces the amount of fuel injected on deceleration--depending on engine speed(rpm) and throttle valve opening(TPS signal)there is fuel cut to the front rotor only or fuel cut to both rotors.The bucking you refer to is usual the result of TPS performance-poor adjustment or a malfuntion.
Replacing the air pump and ACV will not help you.

 

OOOOHHHHHHH!!!!

I'm VERY INTERESTED in this. I've gotten use to slowly letting off the gas @ 4500rpms - full boost - 4th gear. Otherwise the engine seriously jerks.

The worst is coasting in traffic in 1st or 2nd. I hate how the car bucks a bit when letting off or slighly acceleration.

Any LINKS or URLs??

 

Sorry I don't have any.I have a Mazda technician trainng manual which describes how the ecu controls fuel injection amounts.Unfortunately it does not have a whole lot of detail.

 

I get a lot of popping and banging on deceleration with my car...feels like a LOT of GAS getting in the exhaust or something...whatever CAUSE that. So If I replaced my AIRPUMP and got the ACV running NORMAL again, will this eliminate the POPPING/BANGING for sure?

 

only thing i can think of is if you have your acv/airpump off and still running your cats maybe its clogged to hell and choking your cars chicken

 

I am confused about which problem you are trying to solve.In your first post it was "bucking/fuel
cut".I tried to answer that.
Now you want to solve that--easy: reinstall your air pump and ACV,adjust the dashpot to the spec described in the manual were reading and make sure you have no leaks in your exhaust system.If you have a really open exhaust you may have to "over" adjust the dashpot,ie 4.0 kohms.

 

Do you have a scanner or a title for the manual?

Henrik
87TII

 

I hadn't noticed the thing about higher rpms, but maybe it doesn't apply since mine is an n/a iunno. but in 1st or second I have to be really careful with the throttle because it'll buck. so I guess I have the same thing. decelerating I have noticed some soft popping, but just figured that was normal. nothing too loud. definately nothing to call a 'bang'

 

Ok, thanks man for ALL your help! I reinstalled my Air Pump today and NOW going to adjust the dashpot to 4 kohm spec like you said, cause I have 3" piping all the way from the turbo to the exhaust tip, with no cats. That should take care of it. I am aiming towards elminating all the symptoms I mentioned above, the popping/banging, bucking, fuel cut and everything happening when I decelerate.