Okay guys,

Help us make sense of this test. We were trouble shooting a battery/voltage issues and we came across this test in the FSM. So, we decided to do the test and surprisingly the idle RPMs dropped when we did it on his front housing. So, he recently did a compression test and the results were solid so we know it's not compression. We will troubleshoot the other things on the list and see what up. But my real question is, what is the test trying to determine and what does it mean when the RPMS drop?

http://www.flickr.com/photos/9krpmrx8/9725797104/

 

I think we can safely say my Odyssey battery is malfunctioning but it will be interesting to see if this battery/voltage issue is also contributing to the missing rpm drop when we pull the high tension lead (as in maybe being farther down the system see more impact from the weak battery.....also the volts on the battery are good I am assuming its the amps).

I am about to swap a regular battery and take my Odyssey battery to be tested somewhere other than Autozone

 

It kinda says it in the photo...

What it sounds like to me is...
(Example) If you disconnect rotor 1 and the engine runs worse it mean that rotor 1 is working to some extent or fully. Then you disconnect rotor 2 and the engine runs the same, it basically means there is a problem with rotor 2 and it is not contributing to keeping the engine running. It's basically dead weight.

I've done this with a piston engine before to find a dead injector, I just unplugged one injector at a time till I found one that I can unplug and the engine would run the same. This was back when scan tools were kinda a dealer only item and were very expensive.

Just my thoughts..

 

Right, so if it is not firing on that rotor then the other firing rotor is making up for it. And the "bad" rotor could be because it is not firing or just because it's not making compression and contributing. I was just surprised I had never heard of this test anywhere.

 

Correct. If you are disabling the ignition on one rotor and the car is running the same, there is a problem with that rotor, either air, fueling, ignition or mechanical. The test seems dated. Back in shop class +12 years ago, we had a fancy snap-on scan tool that could do this for piston engines. This would be good to use on a older car (pre-obd2) to start narrowing down the cause of a problem.

So if you did this test and the rpms dropped for both rotors near the same rpm, you passed the test. If the rpms drop differently (disable Rotor "X", engine runs the same or not as bad when Rotor "Y" is disabled, there is a problem with Rotor "X")

 

yeppers....we did the test and the front rotor rpms dropped but when we did the rear nothing happened

 

that's just the way to test to see if the rotor is actually "firing"

 

Same thing as a cylinder contribution test. Used to determine if a cylinder (or rotor in our case) is firing. Glad to see everyone is on the same page! LOL

Helpful test when misfire data wasn't implemented yet in the PCM/ Scan tools yet. (It's how I determine cylinder misfires in my girl's 01 Escape)