can anybody explain how to scope the dwell please
ive got a scope and i have the scope pattern for my engine from tec details on it so if im correct if it matches that then everthing should be ok
am i correct and how do it do it
cheers
scopeing dwell
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screamer69
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scopeing dwell
2.0 8v turbo 10.7 standing 1/4@136mph on m/s fastest mk2 astra 8vt in europe !!!
2.0 turbo tigra 10.1 standing 1/4 @ 145 mph with problems
havent turned the boost up yet
2.0 turbo tigra 10.1 standing 1/4 @ 145 mph with problems
havent turned the boost up yetWhat tec details? What is it you are trying to see? Are you trying to see the on time of the coil (ie deg dwell), or how long the dwell should be? (dwell time for MS setting). . . pattern for my engine from tec details on it.
Is the car running to make the scope measuement?
If you do connect the scope input to the '-' terminal of the coil, be sure that you are using a 10:1 probe. Otherwise you may blow the input to the scope.
Hey, I was reading posts trying to learn about dwell and stuff and had a question about lance's method.
IF you have +12V going to the coil, then you have the negative going to MS. Wouldnt you read nothing(0V) and then MS grounds it, so you see 12V on scope for a couple ms(dwell), then when it grounds, voltage drops very low from collapse of field goign back to zero before next spark where it repeats.
I dunno if i'm just reading what you wrote wrong, but it seems as though you say the opposite.
IF you have +12V going to the coil, then you have the negative going to MS. Wouldnt you read nothing(0V) and then MS grounds it, so you see 12V on scope for a couple ms(dwell), then when it grounds, voltage drops very low from collapse of field goign back to zero before next spark where it repeats.
I dunno if i'm just reading what you wrote wrong, but it seems as though you say the opposite.
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jsmcortina
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To scope the dwell connect the scope probes across the current sense resistor R43. As this is 0.01R (from memory) V = IR tell you that when I = 7A you will have 0.07V
James
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My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
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New users, please read the "Forum Help Page".
Here is a picture of what you see at the resistor (top). Note the current rises and then starts to level out. From the beginning of the rise to where it starts to level is the dwell time you want (about 4 ms at 4 amps on this picture). If the dwell were set longer, the current would not appreciably go up and not further charge the coil.
The bottom picture is the trigger at the Tsel jumper. negative going is the trigger.
The bottom picture is the trigger at the Tsel jumper. negative going is the trigger.