Strange timing problem (1 Viewer)

[ariff]

So I have been following the how to set advanced timing post found here How To: Adjust or Advance Timing
I have used this in the past without any issues. However when trying to set timing after my head gasket replacement I am having a strange issue I am hoping someone on this forum could help with. When checking the timing without placing the jumper on E1 and TE1 I am getting about 15 degrees. I follow the directions to jumper E1 and TE1 and this makes the check engine light flash. I am still seeing 15 degrees.. So essentially I am not seeing a smaller degree of timing with the jumper installed.. Right now I have just left it at 15 degrees and it seems to be running good.. I checked both knock sensors and they are plugged in.. No check engine lights. I did remove the Pair valve and the EGR. That should not make a difference.. The only other thing i can thing of is I replaced the ECM with a unit from a 94 due to my 93 ECM throwing 83, 84, 85 codes known issue with the early 93 ECM's . Anyone seen this kind of behavior?

 

[inkpot]

Have you tried resetting the timing back to stock while the jumper is in place? The jumper does not really change the timing as much as it just stabilizes the timing/reading for ease of seeing a consistent setting instead of it floating around by a few degrees.

 

[ariff]

Humm from what I read in the FSM it says set to 3 btdc with the jumper in place. Shut off car remove jumper and re-check timing it should now read around 13 degrees.. When I do this I get 13 with the jumper (CEL blinking) and 13 with the jumper removed. I have tried setting it to 3 degrees, and 7 degrees with the jumper. Each time I do this it does not run very well and idles low.. Hence why I set it to around 15 degrees with no jumper.. Scratching my head..

 

[inkpot]

Timing should not change dramatically with versus without jumper. What page of the FSM are you seeing these instructions on?

 

[ariff]

Well now that I re-read the FSM a little closer (last time I was looking at it on my phone in the garage small text) I see this:
FURTHER CHECK IGNITION TIMING
Ignition timing:
2 - 13° BTDC @ idle
(Transmission in neutral position and A/C OFF)
HINT: The timing mark moves in a range between 2°
and 13
Right now it bounces from around 10 to 15-ish So it sounds like I am ok.. I'll re-check again tonight.. Thanks for your clarification..

 

[Tools R Us]

The jumper is for setting base timing. What the timing is without the jumper is irrelevant, it's dynamic, the ECU adjusts it from base to whatever is needed.

 

[ariff]

Ok I set it back to 8-9 ish with the Jumper installed. Seems to be happy there. No pinging and good idle.. Thanks for the help