I was wondering if there was any diffence with the ACV unit throughout the various years and models? I've deduced mine is faulty. I tried spraying a fine mist of water into the inlet tube of the air pump while revving the engine, and it almost died every time i revved it.

Now while I know its supposed to inject air upon afterburn, I have a very strong suspicion that there's an internal vacuum leak caused by the ACV.

 

I thought I read a post on one of these forums that they did differ but I am not 100% sure.

Anyone else?

 

What are the symtoms of your car? I think Ive narrowed my problem down to either the ACV or EGR also. My car wont hold an idle at all, and there is a whistling sound coming from around those areas..

 

i might have a leak somewhere too since after i removed the ACV and Split Air Pipe i hear a whistle around there as well. a leak of some sort. the car runs fine though. no problems. but still, i'd like to know what it might be and fix it.

 

Symptoms? Hahahah... sure
1. Misfire when revving in neutral above 1k (not backfire, just misfire)
2. Misfire upon decelleration when revving in neutral (series of popping sounds)
3. Rough idle upon warm restart on a hot day (i imagine due to heat soak), goes away after 10 seconds of driving.
4. Low vacuum upon warm restart/hot day. (14 in/hg as opposed to 17-19 in/hg normally)
5. Intermittent loud buzzing sound from the ACV. Seems to be related to misfiring, but i can't figure out how.

What have i done?
1. Set the TPS 104132519073590813906908136 times
2. Pulled the BAC off and tested it, works flawlessly, and is clean as a whistle.
3. AFM is not sticking.
4. Replaced vacuum lines around acv, all except the bottom one which i couldnt reach.
5. Checked throttle cable for stickyness/adjusted.
6. Checked dashpot
7. Re-did grounds (two VERY good grounds, in addition to the stock grounds)


Oh by the way, the issue diminishes when the A/C is on (BAC giving the engine more air).

 

The turbo are completely different than the n/t. This site http://www.mazdatrix.com/c-5.htm seems to show a difference b/t the series four and series five n/t. I've never seen a series five so I can't say what the diff is.

And yes, that anti afterburn valve in the acv can leak enough to mess with the idle. Seems a person could just remove the air pump belt, block off the pipe to and from the acv to confirm if it's messing with the idle. Or just spray starter fluid in the airpump inlet while the car idles and see how radical the idle changes. RAdical change would seem to indicate a bad anti afterburn valve/diaphram. Just mho. No guarantee.