Spark knock at idle

[LGAFF]

I am getting spark knock at idle per the Tech one ....taking out 10 degrees....Flywheel?

[mike100]

audible?

firing order goof or really bad gasoline?

[LGAFF]

It picks up on the Tech 1, I really can only hear the flywheel slightly....

[mike100]

before I replaced my injectors, my car would knock on the dual mass from time to time from an inj misfire (my dual mass has a little play in one direction, but is quiet until you turn of the engine and it decelerates to a stop).

If you can hear it constantly it must be knocking in both fore and aft movements??? does that make sense?

are you in a position to drive it?

[mike100]

you could disconnect the knock sensor temporarily and drive it w part throttle accel. if something is amiss, you can definitely hear the LT5 ping with the windows down.

[LGAFF]

I have a single mass flywheel...

[XfireZ51]

Lee,

What's the motor idling at? We can reduce the timing retard and bump the idle a bit. Also tune for the single mass. I wouldn't sweat it much.

[LGAFF]

idle is 750

[XfireZ51]

idle is 750

Lee,

We could raise that a bit. What about BLM(s) and spark timing at idle?

[LGAFF]

left 160
right 155

-4 at idle

[XfireZ51]

left 160
right 155

-4 at idle

God Lee! Lean misfire!!! You're maxed out on the BLMs.
Need to re-tune that. Call me.

[LGAFF]

Changed the fuel filter, no change....but then I noticed that my Tech 1 has a BLM reset button, that sets BLM counts back to 128 and removes the "learned" counts....

Will see what happens, still show knock

Put some Fuel Inj cleaner in also...I did notive that timing is at 1-2 degrees vs the -4 to 8 it was at...


I also noted that on decel timing drops to -10


Tech 1 should have a label: This is not a toy.....:sign5:

[XfireZ51]

Changed the fuel filter, no change....but then I noticed that my Tech 1 has a BLM reset button, that sets BLM counts back to 128 and removes the "learned" counts....

Will see what happens, still show knock

Put some Fuel Inj cleaner in also...I did notive that timing is at 1-2 degrees vs the -4 to 8 it was at...


I also noted that on decel timing drops to -10


Tech 1 should have a label: This is not a toy.....:sign5:

Lee,

Decel does pull timing. If you noticed a diff after fuel filter, how about the quality of the fuel in the tank? Has it been sitting around for a while?

Do you notice WHEN the knock occurs? The scan tool will detect knock at start up and shut down but those should be of no concern.
I would reset BLMs and Spark Counts w Tech 1 then drive around a bit. See what happens. You should datalog with a scantool so we could see what is happening when.

[LGAFF]

beginning to think its the knock sensor filter/elec spark control....unplugged the knock sensor and still getting 10 degrees of timing retard at idle, and when I floor the car the timing drops to 6-8 degrees......surprised the car is this fast

[LGAFF]

FSM says that if the knock is present without a code 43 ESC is bad, I have an internal engine problem or the wire is picking up a false knock.

Anyone know who sells the ESC module?

[Pete]

Get new knock sensor,done.

Pete

[LGAFF]

I unplugged the sensor and the knock was still there..per FSM I believe that points to the ESC...

[Pete]

If you don't have a short.
Change knock sensor,it's cheap and will save you time and headache.
Just trust me on this.

Pete

By the way the 1990 knock sensor is different.