LSx Ignitions
LSx Ignitions Anybody seen what the scope trace for the secondary side of the ignition looks like? what gives? there is no definite "dwell" time, no coil oscillations at the end of the plug fire. i could barely tell where the plug quit firing. can anybody explain?
TECH Resident
Joined: Dec 2004
Posts: 845
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From: K-W, Ontario
Where did you see this?
The oscilloscope should show a defined peak in voltage and a period of time between
firing.
Chances are, the time base om the scope was set to sample a long period of
time.
The oscilloscope should show a defined peak in voltage and a period of time between
firing.
Chances are, the time base om the scope was set to sample a long period of
time.
TECH Senior Member
Joined: Apr 2002
Posts: 6,080
Likes: 17
From: So.Cal.
Using an inductive clamp probe, my cheap scopemeter I see a sharp spike followed by a sharp drop, and then flat zero until the next one; I can measure the period between firings and it agrees with 2/RPM.
Sorry, I don't have any pics of this.
When I switched to spiral wound low ohm wires, the EMI emission level is so low (pretty much zero) that my inductive clamp probe fails to pick up any signal, the scopemeter fails to trigger; is this what you're seeing...?
Sorry, I don't have any pics of this.
When I switched to spiral wound low ohm wires, the EMI emission level is so low (pretty much zero) that my inductive clamp probe fails to pick up any signal, the scopemeter fails to trigger; is this what you're seeing...?
these were stock wires and plugs w/ 65K miles on them. i got a LQ4 in the shop and i'll see what its pattern looks like tomorrow. on my car, i got a firing line of about 12K, a burn of about 2mS at i cant remember what voltage, a +1KV spike at the end of the burn line, and then a downward sloped line to 0V. it stayed that way until the nextfiring line occurred. i'm thinking i might not have had a good ground, so like i said, i will do some more testing tomorrow or thursday, if i can keep this LQ4 for that long.
