Are Yo Sure It Said Code 18? Or Did It Say Code 16? Code 16 Is Ignition Not Detecting The Low Resolution Signal On 5.7 V-8s.
Most Of The Time This Can Be Related To The Optispark. My Old Gm Manual Is Not In The Best Of Shape So I Could Be Missing Code 18 If
Does Exist.

 

Yah I'm sure it said code 18. I have no idea what that means. Thanks, I'm leaning towards the opti also. Could anyone answer if a knock retard of 9 is normal under wot?

 

Give Me A Minute.

 

Code 18 Indicates A Problem In The Cam Or Crank Position Circuit.
The 9 Deg Of Knock Retard May Or May Not Be Related. WERE YOU ABLE TO SEE YOUR TIMING ADVANCE WITH
YOUR LAPTOP?

 

knock retard of 9 is definitely not normal. That is way too high. Ideal retard is zero.

And the above post is not correct re: code 18. Code 18 is an injector circuit fault. That could cause you to run bad because the injector which causes that code is typically disabled. You have to do an injector test to see which injector is bad.

 

The Other Person Is Correct. It Is An Injector Related Fault Code For P-engine Codes. Sorry For The Mistake.

 

INFINITEBIRD, IS IT CORRECT THAT THIS CODE MEANS Injector driver circuit voltage to PCM was wrong for 4 seconds. PLEASE CORRECT ME IF AM WRONG.

 

yes, that is correct

 

Thank You Very Much. Do You What Steps To Take From Here I Am Missing A Few Pages Out Of My Gm Book And The Code 18 Section For F-bodies Is One Of Them.

 

Infinitebird , Are You Still There????

 

it said something about performing an injector balance test to determine which circuit was faulty, and then testing that circuit to see it was bad (electrical/connection problem), or if an injector was bad.

 

You guys are great, thanks alot. How do I test the injectors? or should I just go buy new ones. Or do you think it could be a wire going to the injector. How do I fix the knock, I don't know what is causing it, I just used free scan and drove around, while I was recording it. Sorry for all the questions but this is my only car and I work 5 days a week with school afterwards.

 

I Would Not Replaced All The Injectors At This Point Without Doing The Test. If You Remember Alot Of People Thought It Was The Optispark Or O2 Sensors. It Would Be Wise To Get Some More Info Like Getting Repair Manual. Some Of The Stuff You See At The Auto Parts Stores Are Very Limited And Dont Get Down And Dirty When It Comes To This Stuff. A Good Wiring Diagram Can Help You Determine If Its An Injector,harness,or Pcm Related. If I Remember
Correctly The Resistence Reading On The Injectors Were Between
11 To 14 Ohms. If You Have A Multimeter You Can Check The Resistence Of The Injector By Placing The Neg And Positive Leads On The Pins In The Injector. This Can Tell You If You Have A Injector
That Is Shorted Out Or Has An Open Circuit. Those Reading Can Be Within Spec When They Are Cold And Go Out Of Spec When Its Hot.
The Gm Tech 2 Scanner I Used To Have Made This Alot Easier To Diagnos. I Hope Infinitebird Can Add More Info To This.

 

I think I can rent a meter from autozone and check the voltage in the parking lot. I drove it to work today and it seemed to run fine, except still stuttering at high rpm's. I won't beable to check it tomorrow, but wednesday I will. Will it be ok for me to keep driving it or should I borrow someone elses car.

 

I Would Also Like To Add That The Pcm In Your Car Is Designed To
Reduce Timing Up To 10 Deg. So 9deg Is Right At The Max. The Knock Sensor Control Module Is Located In The Pcm And Can Be Replaced
Seperatly If Needed.

 

You Should Be Fine Unless The Car Gets Worse And Starts To Shut Off.

 

Last Year Ireplaced The Optispark With Reman Part From Advanced
Autoparts With A Lifetime Warr. Would You Believe That I Have Yet To Have Any Problem With It. It Does Not Come With The Cap And Rotor. I Got That From Msd Through Summit. Just In Case You My Need 1 In The Future And You Dont Have Alot Cash. Its Not That Hard To Put Together. I Use To Think That The Originals Were Really
That Much Better, But I Have Seen Them Fail In 6 Months.

 

Ok, well I was gonna buy a 60,000 mile good condition opti off this guy on here for like 60 bucks just in case. I am planning on putting in a LT4 knock module when I install the long tubes, but I would like to know what is causing the knock. I was just reviewing my scan and noticed that 5-9 deg was the norm during acceleration hard or not and peaked at 13 under some WOT pulls. The car just falls on its face at around 5000 or so. Shifts great and spins the tires still but has no ***** up top anymore with the stutter. I will check the volts on the injectors on Wed. Also I saw that the o2's were at a constant .95 volts the whole time is that good?

 

abnormal combustion will cause knock readings to rise. A FAULTY INJECTOR CAN CAUSE THIS IF ITS NOT OPENING UP ALL THE WAY. JUST TAKE 1 STEP AT A TIME. MAKE SURE
YOU DONT HAVE ANY OIL IN THE KNOCK SENSOR OR IN ITS CONECTOR. OIL IN THESE SPOTS CAN ALTER READINGS. THE SENSORS ARE LOCATED ON THE SIDE OF THE ENGINE BLOCK.

 

OK. Will oil come out if I pull the knock sensor out of the block? I'll check that also to see if it has a good connection.