trailing plugs not firing (stock ignition, microtech lt8)
trailing plugs not firing (stock ignition, microtech lt8)
I have just hooked up my microtech and in teh midst of trying to get my abomination running, The trailing plugs were firing last season with stock ecu. I have ignition switched power to both brown wires of the trailing coil I have the tach hooked up to the yellow wire and the the microtech lt8 two trailing wires hooked up to the correct wires. Im kinda stuck right now. the leading plugs will fire and the car will kinda start but just totally stumble and die.
is there something in the microtech that could be causing this? did the coils spontaneously implode itself?
any input is appreciated
Mathew
is there something in the microtech that could be causing this? did the coils spontaneously implode itself?
any input is appreciated
Mathew
Last edited by mot_bot; May 24, 2011 at 05:29 PM.
microtech does not fire the trailing coils while under the crank speed threshold
similar for several other ECU's,, they default to "non sequential ignition and injection"
during the low voltage cranking phase
ignore the trailing plugs until you have the engine idling
the engine bay tacho wire should be hooked to the micro tacho output, methinks lt8 is blue/white
my guess is you have too much or too little mixture and the timing calibration is out
disconnect the fuel pump relay and crank the car with timing lock on , static zero , and set the timing to the -5 ATDC datum mark
be aware this "microtech" method will make all your maps 5 degrees out from real crank figures
alternatively if the motor is heavily ported,, use the current 15 split gap marked on the pulley copied onto some veriners or calipers
and project the calipers clockwise forwards from the -5 mark
this will make a 10 BTDC mark,, do it again and you also have a 25 BTDC mark
set the static to 10 , timing lock on , and time the engine to the 10 BTDC mark
this is "my" method of timing the microtech to be TRUE crank degrees
the 10 BTDC will make the wilder extendies and bridges continue to idle
be sure to remove the timing lock when the CAS is locked down and enable/replace the fuse into the fuel pump relay
then use the mix trim to adjust mixtures to sustain idle
once you have established how much rich or lean it is on the mix trim,, that info can be zerod there and moved to the correct idle, load or coolant sensor trim map
similar for several other ECU's,, they default to "non sequential ignition and injection"
during the low voltage cranking phase
ignore the trailing plugs until you have the engine idling
the engine bay tacho wire should be hooked to the micro tacho output, methinks lt8 is blue/white
my guess is you have too much or too little mixture and the timing calibration is out
disconnect the fuel pump relay and crank the car with timing lock on , static zero , and set the timing to the -5 ATDC datum mark
be aware this "microtech" method will make all your maps 5 degrees out from real crank figures
alternatively if the motor is heavily ported,, use the current 15 split gap marked on the pulley copied onto some veriners or calipers
and project the calipers clockwise forwards from the -5 mark
this will make a 10 BTDC mark,, do it again and you also have a 25 BTDC mark
set the static to 10 , timing lock on , and time the engine to the 10 BTDC mark
this is "my" method of timing the microtech to be TRUE crank degrees
the 10 BTDC will make the wilder extendies and bridges continue to idle
be sure to remove the timing lock when the CAS is locked down and enable/replace the fuse into the fuel pump relay
then use the mix trim to adjust mixtures to sustain idle
once you have established how much rich or lean it is on the mix trim,, that info can be zerod there and moved to the correct idle, load or coolant sensor trim map
wow, so ive been worrying about the wrong thing all this time lol... so once it fires up the trailing coil will kick in?
Ill give the retiming calibration thing a shot, thank you so much for your input.
Ill give the retiming calibration thing a shot, thank you so much for your input.
Last edited by mot_bot; May 24, 2011 at 09:30 PM.
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