ERAUMAZDA

Im getting a rich mixture on my RX what could it be? I sand blasted the plugs and they look fine. Could it be my O2 sensor? How could I test the coil pack safely with out zapping my self.

ERAUMAZDA

Hellllllloooo Need help here!!!!!!!

Scott 89t2

how do you know it's running rich?

dr0x

Our cars run rich until fuel cut

HAILERS

Hellllllllllllllllooooooooooooooooo! There is a free online factory service manual at http://www.fc3s.org and at http://www.iluvmyrx7.com and each manual has a section called FUEL, that tells one how to check out each component plus the output/input to the ECU when at idle.

If running rich at idle, and you have a 86-88, you might check and see if the variable resistor needs adjustment. See the FUEL SECTION. If running rich overall, you might check and make sure the o2 sensor is putting out to the ECU, or a bettter bet is to check out the water thermo sensor on the back of the water pump housing to make sure its working. Open water thermo causes bad fuel mixture.

Check the pressure sensor is up to snuff. Make sure its vac hose is on.

If you have a 86-88, you might make a ECU code checker and see if a code pops up. DISCLAIMER....86-88 codes really only tell you is a sensor plug has fallen off, on the whole.

Set the timing with a timing light and right on the mark.

Check the compression. Low compression equals thirsty car. In general, please.

P.S. RX-7 really don't get anything close to GREAT fuel economy. More or less average at best.

There's no real simple answer to why the cars running. rich. Going to take a bit of digging.

ERAUMAZDA

Thank you so much..... Your words of wisdom will set me off into a journey to find the answer to my problem.

Also I have a rich mixture because I can smell way too much gas out the exhaust... a performance drop and snap crackel pop from the rear.

Rotorific

iTrader: (1)

Man you need to learn that RX-7s smell like that all the time even if you are running lean.

ERAUMAZDA

I understand that but I know I have some kind of problem because some days its rich and some days its not. This is not a constant thing and second I am idling at 1,500 from some reason some Im guessing a sensor is shot. My varible resistor looks like it bit the dust. I Am an aircraft tech and im trained in turbines and recips. So I always come here (my home) for advice so I don't screw something.

Rotorific

iTrader: (1)

A 1500 idle is really simple stuff. You need to check your TPS first if that is correct then you need to check your Idle adjustment screw on top of the throttle body make sure its not sticking to far out of the tb. If this problem only happens so often or it does it occasionally then i would check the spark plugs. Worn or bad plugs will trully mess up your idle. -Gabe

HAILERS

Since you work on the largest LRU on the plane for a living, you desreve some help. How long has your car had this fifteen hundred rpm idle?? Does it come and go or on the whole just idles at 1500??

Screwing with the variable resistor at 1500 won't make any noticeable difference as you screw rich/lean. Gonna have to get the idle down where it belongs, 750.

Get the engine fully warm and install the initial set coupler while idling. What happen as you did that? Did the idle change dramatically???(sp)

What year is this car???? N/a or turbo???

I guess I might have been a touch of a smart *** in the first post.

ERAUMAZDA

I have a rx-7 88 vert N/A of course. I had a problem before with the idle it was idle at 2,000. than blamed it on the solenoid just below the bac. I changed it and the idle went down to about 650 to 750. A couple weeks later car starts at 3,000 and stumbles down to 1,000 to 1,500. I have no idea if this has to do anything with the mixture but im going to narrow it down to the O2 sensor, TPS, or even the water temp sensor causes it showing a really cold reading.

HAILERS

I'd dismiss the o2 sensor. Not supposed to be in the loop at idle.

If it starts up at 3000 for 17 seconds, and then drops down to somewhere around 1200.....thats normal. Thats the bac working in conjunction with the air bypass solenoid valve for 17 seconds to give the 3000 grand at startup.
But after the water comes up to running temp, the thermowax should extend and drive the fast idle cam off the roll pin, and give you a 750 idle. See the FUEL section for what I'm talking about.

Then again, it could be a dirty bac(sort of the latest thing to blame the last couple of weeks). You might want to take it off and shoot some lubricant into it and clean it out. I have had one on my turbo car stick and give me a 1100 idle. Swaped in a new/used one and alls well now.

If its idling at 1100, can you take hold of the throttle linkage at the front of the throttle body and with your fingers press towards the throttle off position? Does the idle drop when you do this? Does it drop and stay dropped when you let go?