12 replies to this topic

[Jim Venable]

Pulled this from the Flying Miata site.

 

The timing light gets hooked up to the number one (closest to the front) spark plug wire. You can get +12 volts from the blue connector located near the front of the driver’s side fender. You can ground the negative lead of the light to the valve cover.

There is a diagnostic box located near the top of the left front shock mount. This box is about an inch square and is black in color. Open the lid and you will find a little map of the terminals in it. Use a paper clip or piece of wire to jump the GND and TEN terminals together. You want to do this after warming up the car to normal operating temperature. With the jumper installed, your idle should be about 850 RPM. If it is incorrect, adjust it with the idle air bypass screw located on the throttle body. The screw is under a black rubber cap. Clockwise lowers the idle, CCW raises it.

 

Considering our cars have a kill switch, is this procedure applicable or might there be a different format? I understand the switch must be in the open position. 

 

Thanks again.

 

 

[Keith Novak]

With the kill switch open, there is no power going to plug #1.  Plug #4 is the farthest away from #1 so you need to measure there instead.  

[marcusmazza]

Nice!

 

Jim,

 

The kill switch needs to be on, otherwise the engine will not run. You cannot set timing unless the car is running. Having a kill switch does not effect the timing procedure. Depending on the tuning of your AFM, getting the car to idle at 850 rpm can be tricky. If the idle is off even a couple hundred rpm, you will get a much different reading. Because of this, many 1.6 guys don't really care what the absolute number is. They adjust the timing on the dyno, and leave it there. If you have trouble getting your car to idle, let me know. There are some tricks you can play, but they involve opening the AFM and either adjusting the clock spring, or using something to hold the flapper door shut (not all the way).

 

-Marc

[AW33COM]

^ What about if your AFM is stock?  In other words, can you set your RPMs to 850 without touching the AFM?

[Keith Novak]

The kill switch needs to be on, otherwise the engine will not run. You cannot set timing unless the car is running.

He would have figured that out pretty quickly on his own with no harm done.  Someone apparently sent him on a snipe hunt with the open kill switch advice.  I was just pulled the obligitory, "There's no snipe over here but I think I've seen some over there."    

 

^ What about if your AFM is stock?  In other words, can you set your RPMs to 850 without touching the AFM?

Standard proceedure.  You should be able to get to 850 unless something else is up like a vacuum leak.

[AW33COM]

^ Was just making sure as I followed the standard procedure.

[Jim Venable]

Unable to connect the timing light to the blue box (auxiliary power connector) as it was used to hard wire the transponder. Didn't know better at the time. Is there another power source in the engine compartment that can be utilized? If not, would adding a pigtail to the auxiliary power connector be acceptable or might it interfere with the transponder operation. I would think not but want to be sure as my electrical skills are minimal at best. 

 

Thanks again and for the previous answers as well.

[pat slattery]

Scribe a mark on the cam sensor and the head portion.  Then make small moves of the timing both ways while running dyno runs and find what works best for your car.  Much easier.  You don't have to move it much, just a hair width in increments.

 

pat

[Keith Novak]

Unable to connect the timing light to the blue box (auxiliary power connector) as it was used to hard wire the transponder. Didn't know better at the time. Is there another power source in the engine compartment that can be utilized? If not, would adding a pigtail to the auxiliary power connector be acceptable or might it interfere with the transponder operation. I would think not but want to be sure as my electrical skills are minimal at best. 

 

Thanks again and for the previous answers as well.

 

I did the same thing so I wired a pigtail.  It works fine.

[MazdaSteve]

You can use the power supply under the plastic cap on the alternator.

[Kyle Freiheit]

Unplug the transponder while setting timing? I made a split connector(Y junction) with with a couple spade connectors that plugs into the blue box.  That way I could run the transponder and grab 12V for anything else. 

 

Kyle

[Jim Venable]

Used a long set of jumper cables from the battery before just now reading the responses. Much appreciated. Will attach a pigtail for ease of access in the future. Earlier when setting the timing, this thought ran through my mind.

 

The purpose for connecting the timing light to the battery is to provide power for the light which caused me to wonder. While not 12 volts, would a 9 volt big flashlight style battery be sufficient to generate the needed power? I would have tried it but didn't have a battery handy.

 

Setting timing concerns:

 

It is my understanding the RPM's would stay the same or reduce slightly upon grounding the ECU. Mine increased a couple hundred. Is this normal or should I be looking for an issue? 

 

The idle can be increased by turning the idle adjusting screw counter clockwise but cannot be decreased clockwise as it's already to the max adjustment. Idle is a tad over 1,000. Thoughts please.

 

 

 

 

 

 

[marcusmazza]

Jim,

 

My idle increases slighlty as well when I ground the ECU, although only like 50 rpm or so. The engine idling at 1000 rpm will throw off your timing measurement. It really shouldn't be idling that high with the idle adjust screw all the way in. I would make sure the engine is at full operating temp. My car will take well over 10 minutes at idle to come up to temp. When the engine is cold, it will idle at over 1500 rpm. There is a valve on the intake that controls the idle (wax style valve). When the engine heats up, the valve shuts. This could be your issue. I would also look closely for vacuum leaks. Third possibility is the butterfly valve in the throttle body isn't sealing (either the throttle cable is out of adjustment, or the valve is dirty or has lost the special coating).

 

-Marc