Haven't had time to work on this. New cats get here next week. Does this relief valve effect emissions? Not sure how important it is to get this valve addressed. Car has been running good although cold idle hits 3500-4000rpm instead of 3000rpm.

 

Got my emissions rechecked. Still failing.
Installed two new CatCo cats, new O2 sensor, new fuel filter

1163RPM
HC MAX-220 MEASURED-1152
CO MAX-1.2 MEASURED-4.957
2541RPM
HC MAX-220 MEASURED-639
CO MAX-1.2 MEASURED-7.355

Had mechanic try to diagnose it. He said his SnapOn Brick 160 couldn't access the computer. Also he said at idle the CO percentage would come way down to 1.7% and then jump back up. His guess is coolant temperature sensor could be bad and telling the car to use more fuel since it's not hot enough. However, if that was the case then I would think the car would be idling at 3000rpm like it does on a cold start. He also suggested it could be fuel pressure relief valve not working. Another idea is that the ECU is bad since his SnapOn can't access it. He didn't think the TPS would be the cause.

At this point I can get an emissions waiver since I've spent over $200 trying to fix it and things have improved. However, my gas mileage isn't very good. I'm not sure what this car should get, but I'm getting 17MPG mostly highway miles with conservative acceleration.

Is the relief solenoid related to the fuel pressure relief valve? Any ideas what could be wrong?

 

Took my car to the dealer for diagnostic. They did compression test, which is ok.
Dealer says I need a new Air Control Valve, which is out of stock.
part # N350-13-990A

Any ideas where I can find a used one?
Or should I pay $357 for a new one from MazdaPartsUnlimited?

 

This web site is my life blood. I use them for parts i can not find anywhere else. Let me know if it works out. FYI call the yard before placing an order.

 

I'd suggest against purchasing one new. People remove them all the time and can be found in the 2nd gen classified parts section.

Sounds like you need 'port air' which is a function of the ACV. However, it is controlled by two vacuum lines, a solenoid, and ecu signal (which includes input from the TPS). The failure can be anywhere, not just the expensive part on the end.

If you can mess around with the car while it is getting inspected. Try feeding engine vacuum straight to one of the ACV ports. If the emissions suddenly clean up, you found the right one.

 

Thanks for the lead.
I found this place searching for the part number on Google.
MAZDA PARTS AND EQUIPMENT LIST - SA642
Sent them an email asking if they have the part.

 

This is why I come here. You guys are smart. The mechanic said there is a vacuum leak at the air control valve.

Unfortunately there are no rotary mechanics that I can find in Salt Lake Valley. Wondering if my mechanic will know how to 'feed engine vacuum straight to one of the ACV ports'. Is that pretty straight forward for any engine mechanic?

 

Also I'm planning on a ECU swap to Megasquit, Haltech or Adaptronic. Will those ECUs eliminate the need for this ACV?

I've noticed a lot of emissions control stuff gets eliminated with the Megasquirt.

Wondering if I should just get started on that project and quit wasting time and money on this issue.

Thanks!

 

No aftermarket computers needs emissions equipment. I've successfully passed tons of vehicles with aftermarket computers. I would be more than happy to help you get through it with an Adaptronic.

 

hey man. im slc local and i dont mind helping rotary guys out.

send me a pm if you need any help

 

Finally found a mechanic that works on rotary engines, Master Tech. (Also Phil at Master Muffler). They initially found the intake manifold and exhaust manifolds leaking air and said I'd have to fix that before they could diagnose further. In the end it cost $912 at Master Tech to get my car to pass emissions. Now it passes with flying colors. Only 2 ppm on hydrocarbons, down from 1927 ppm.

Now my only complaint is the acceleration lags out around 7000 rpm. I'm usually shifting before 5000, but would like to figure out why it's not happy at 7K. Also it idles so slow now that I have to rev it up before it wants to go.

This is list of everything they did.
- Repaired all vacuum leaks
* Four broken vacuum lines under intake manifold
* One broken vacuum nipple on diaphram
- Cleaned and flow tested injectors
- Installed new filter screens in injectors
- Flat filed intake manifold surfaces (warped and damaged surfaces)
- Reinstalled all items removed with new gaskets, seals, and clamps
* Parts removed: Upper fuel rail, lower intake manifold, exhaust manifold
- Replaced brake booster hose that was leaking
- Repaired seized actuator in lower intake manifold

Now it's running pretty good. It has idle issues and they said the part isn't available to fix that. Not sure what part that is. They didn't know the name of it so I'll probably take it to Phil at Master Muffler.