ok i know my opti is bad on my car, and i have 2 other ones in my garage, one is a good one and the other one is not. I need to replace the opti on my car, how can i tell which one is good w/o putting it on the car?

would it work just to connect the opti harness to the 2 optis and do the opti/icm/coil test?

thanks braden

 

contact jeff creech at carolina auto masters he can tell you how to do it. been so long i forgot.

 

Just bolt it on the car, put all of the plug wires back on, and fire it up. Leave the water pump, belt, fan shroud, etc. out and see how it runs.

 

whats the # do you know?
i have no clue who he is.
thanks for the reply

i would like to really test it with out putting it to the engine, because if for some reason the "good opti" went bad i dont want my parts stitting in the garage for a long time (i am going to be traveling to wyoming and colorado to go hunting for a long time). but if i cant think of ne thing else ro if there are no other ways i will do it. thanks for your comment.

 

Put 12 volts to pin "C" which has the red wire going to it when it's plugged in. Put the negative side of the 12 volts on pin "D" which has the pink/black wire going to it.

Now measure from pin "A" (the pin with the red/black wire on it) to pin "D" with a voltmeter and see if it goes from 0 to 5 volts and back as you rotate the drive slowly. That was the low res signal.

Do the same thing for the hi res signal from pin "B" (has the purple/white wire on it) to pin "D" and see if you get the same results as the low res pin above. Turn it slower here as there are many more pulses.

If you turn it too fast, a digital voltmeter may not be able to keep up. Also the 2 foot pigtail off your car will help to hook up both the source and the meter as the pins directly on the opti will be too difficult to deal with.

 

I am told you can do a rudimentary test by connecting the test opti up to a car and turning the opti drive. Just hook it up (harness and coil wire) to a car and put a plug wire and old plug on it. Ground the plug body. Turn on the ignition and spin the opti drive. The plug should spark.
While not a performance test, it's at least something.

 

whats a good 12 v source to use? how could i conect a car bat to the opti, just with a wire? and does it mater the length and diameter of the wire?

 

thats what i was thinking as well, i think i will go and try it, i will hook the harness up, then the coil, one wire and a plug and ground it and we will see if she sparks.... never know unless ya try right?

 

i belive that is the way jeff and i did it to mine, years ago. bad opti out of the box lol

 

i just did what you said shoebox and didnt get crap ahhah from either one.... maybe they are btoh bad... well it looks like i will do the digital meter test, if i have to buy another freakin opti i am to go insaine!!! my car is an opti eater! i have bought 4 now. but when i took the last one off it worked still, i had a prob with my ICM, so i am a little confused. It should technically be good... but thats my luck that it went bad

 

cana a good opti go bad just sitting there? for two years haahah ( i just go tback from honduras)

 

^that's a good question about the opti going bad from a car sitting for an extended period of time (such as 2 years). I've wondered this same thing myself.

 

well i did the tests on the whole icm agana nd what do you know, no 1 to 4 volt change on the icm harness. so i changed my cmoputers ( i have 2 tuned for my car) and nothing. so it is down between the opti and the harness, the both of which were new before i went t honduras for 2 years... one has to be a faulty part!!
HOW DO I DO A TEST JUST ON THE HARNESS?????

 

Was the harness in the car? Perhaps some small rodents got in there and went to chewing on the wires. It happens a lot with cars while they are stored. Stupid animals eat the cover.

 

Make SURE that you ground the opti itself [touch the aluminum base ear to ground, or use a jumper etc]or it won't work....