Help with spark retard
Thread Starter
Instructor
Joined: Sep 2006
Posts: 185
Likes: 2
From: Easton PA
Help with spark retard
I have an 88 auto trans 24k car. the car is stock accept for Fic Bosch 22lbs injector and a tune from a very good tuner. The car runs great but I get spark retard only at WOT I see as much as 12 degrees. The timing is set at 6 degrees and I run 93 octane the car is not pinging what is the normal spark retard for these cars as im not sure if im chasing a ghost. I have checked the knock circuit as well as the egr circuit. I am not sure if the spark retard is effecting the performance. With a g-tech the car run consistent 5.7 seconds to 60MPH (2:73) rear
while data logging I noticed that the car will register knock on hard downshifts and upshifts causing spark retard I will typically get 1 or 2 knock counts and up to 12 degrees of retard for those knock counts. The only thing I have not checked yet is the exhaust systems for blockage. I should also note that the spark retard is the same if I back the timing to 2 degrees BTDC. a normal WOT run will show 7 to 8 degrees retard then it slowly backs off.
while data logging I noticed that the car will register knock on hard downshifts and upshifts causing spark retard I will typically get 1 or 2 knock counts and up to 12 degrees of retard for those knock counts. The only thing I have not checked yet is the exhaust systems for blockage. I should also note that the spark retard is the same if I back the timing to 2 degrees BTDC. a normal WOT run will show 7 to 8 degrees retard then it slowly backs off.
Last edited by ray1979; Aug 7, 2014 at 11:05 PM.
Safety Car
Joined: Sep 2001
Posts: 4,150
Likes: 551
From: Glenbeulah Wi
If you know what you are listening for I would recommend disconnecting the knock sensor and find out if the car is really knocking on the WOT hard upshifts or downshifts by listening for the pinging. This will help you identify real knock vs. false knock. If the car is not knocking you can have the MAX WOT knock retard limited to around 6 degrees to keep some safety in the system. You could also decrees the aggressiveness of the knock retard and increase the knock retard decay rate to pull it out faster. If it is real knock you need to determine why it is knocking and eliminate the cause.
Thread Starter
Instructor
Joined: Sep 2006
Posts: 185
Likes: 2
From: Easton PA
today I disconnected the knock sensor and took the car for a drive. there was no sign or sound of ping or knock and no retard. the car pulled much stronger. funny thing is when I disconnected the knock sensor and started the car I had a code 32 isn't that an egr code. when I got home and plugged the sensor back in the code went away. how is the egr related to the knock sensor?
