code 18...distributor no signal...its causing my car to miss badly when it warms up...and throwing a check engine light...i put 2 new distributors in it the connector is clean and i dont kno why but the pcm i guess isnt gettin the signal form the opti
anyone had this problem or have an idea shoebox some1???
thanks
daniel

 

DTC 18 is for injector circuits. Why are you messing with the opti?

 

I wonder if its a "typo" and he meant DTC 16? But then if he had DTC 16, the engine wouldn't even run, so "missing" wouldn't be possible.

Confusing.

 

ok on the scanner it said 18 then""no signal or opti failure"" the words are more important so thats my problem i have put 2 new opti in it and it still has this code...in the scanner it says check the plug but its clean and making contact...some1 told me to find the signal wire and use a meter to test the signal comming from it...but i dont understand why 2 brand new opti's are not sending any signals

 

I know that some optis come bad, even brand new, but two bad optis is kinda out of the question for being defective. The opti maybe good, but perhaps the harness is bad, or the PCM is not sending a signal to the coil at times, for it to send the spark to the opti. Another this is, perhaps your ICM is going bad, and once the car is warm, it starts sputtering. Try this write up that shoebox has wrote, its great..

Opti Test

another thing, I think you might be getting the wrong code or something, because I HIGHLY doubt the scanner knows your car has an OPTI, they usually say distributor failure..

 

So what you're saying is that you believe your scanner, and that DTC 18 means the Opti failed, even though we are telling you that, based on numerous published references, and our own extensive personal experience for over 10 years with LT1's, your scanner is right, and everyone else is wrong. You asked Shoebox for help, and he told you your scanner is wrong.... but because "the words are more important so thats my problem" you're going to ignore him.

According to your post, your car is running.... but it is missing badly. That means the PCM MUST be getting at least the low resolution pulse from the Opti. If is was not sending the low res pulse, the engine WOULD NOT BE RUNNING AT ALL. If the "signal" that was missing was the high resolution pulse, the engine would continue to run normally, and would not misfire. There would simply be an imperceptable increase in spark scatter.

On the other hand, a faulty injector or injectors would make it mis badly.

Good luck.... you're going to need it.... oh, and deep pockets for all those new Optis.

 

very well put. Thats what lead me to believe his scanner is wrong. Especially with the "OPTI" part about the code...

 

Most often it is the code interpretation (the "words") that are wrong (or are from a generic, non specific list). This being the case, I would be more likely inclined to believe the numeric code first and the verbal interpretation second.

Just as a backup, you might want to consider looking into the injectors circuits to see if there might be a problem there.

 

ok mayb im a dumbass im not tryin to tell yall im right but i so know that it was code 16!!! sorry guys...it has no low res signal when it heats up...so i dont know what the problem is with 2 new optis...what could it be how to test this and see where the problem is???
no injector problems...strictly opti no arching and no bad plugs

sorry guys didnt wnana get on ur bad side just need a lil diagnosein help
and i kno with no low res the car shouldent run but my mechanic said it would and i told him i just drove the car up there...under a load the car feels great cruiin about 50 in the a54 is great but stop at a light your eyes start waterin form th gas and it soulds like a cc306

 

help anyone???

 

nobody knows what this could be??? or yall dont believe me???