Help no spark in trailing !
 

Hi im going crazy cause my car was just running fine and it stop turning on!The car is a turbo 2 with a LT8 microtech.Ive found im not getting spark from trailing 1 and 2.Leading one and leading 2 is fine the car was just running ive already change wires, spark plugs , and coil with igniter also the wiring loom looks fine !

please anybody help me !

microtech,, and many other ECU's for that matter are non-sequential during cranking

- ie,, all injectors batch fire ( not primary then secondary )
and the ignition reverts to leading only spark


-- your chasing your tail thinking your trailing IG has a bug when it dont

disconnect the CAS,, remove the plugs,, crank it dry
then try again,, its flooded or has low compression,, or both

OK well start by pulling the plugs out see if its flooded ! I doubt its low in compression due to it was just rebuild ! thanks for the guidance

trailing doesn't do anything other then give you slight power gains and better fuel economy.

I drove my n/a with a burnt out trailing igniter for 2 weeks. Mileage wasn't as good but the increase in fireballs was fun :)

In FCs, the tac gets its signal from the trailing igniter/coil. If its screwed up then your tac will be too (my tac didn't work at all :P)

Car should start without trailing spark, won't be your problem :(

ok thanks for the in fo guys im checking plugs and a compression test this weekend.And curosity does any one know what configuration should be on the microtech for 13bt on the ignition maps thanks

Red light on microtech is going red its showing REF and RPM are error!

then its having a problem with the CAS input
the issue may well be HV interference of the CAS signal
check, recheck your CAS wiring,, route it away from the HT leads and B+ wiring , regap the CAS pickups to 0.2 mm

make sure the ignition leads are resistive suppression type ( or the sparkplugs )
noisy type sparkplugs ( bike ones ) can be used as long as the leads have suppression

LT or LTX or LTS micro?

LT is for stock coils in leading wastespark and also toggles the trailing coil
and thus uses less outputs than the LTX and LTS which are sequential ignition and use 4 individual coils fully sequentially ( no wastespark )

in screen 31 your LT should be setup as 4 cyl ( config ) and mazmode or similar in ( firing ) screen

LTX would read 4cyl,,sequential


i suspect you want to know the input trigger and spark trigger defaults for stock 13b coils
usually
screen31 config= 4cyl
dwell type = duty
dwell= 26%
pump dwell = 26%
input trigger +
output trigger = s4

Thanks for the info the configuration on the input trigger and spark are fine just like you listed so thats good. I'll double check wiring and the ignition leads and re-gap the cas pick up.But Is it a possibility that the cas is just bad?

both ref and home errors up is indicating both channels in the CAS are giving a faulty signal

--very unusual that both would give up at the same time
to me the bug is screaming significant RFI issue

first ,, reset error logs by holding in the mode button in for several seconds

- usually the issue is the ground wire for the ignition harness being wired incorrectly ( should go to the BLOCK )
or with poor shielding and routing of the CAS wiring along with poor HT spark leads

make sure all the connections of the CAS wiring have continuity across the wiring connections
( notorious for poorly connecting harness pins )
make sure that the wiring exiting the CAS does not short to earth at the CAS rubber grommet
( notorious for having bare wires earthing in the CAS at the grommet junction )

if possible,, change HT leads for suppressed type, and investigate adding alum tape to the outside of the CAS wiring bundle
( trap the CAS shield armour under one end of the tape to complete the faraday shield )
check that the main ECU earth goes to the battery,, the main ecu 12V ( red ) feed comes from the battery
( directly ,, as it uses the battery like a cap to prevent current surging )
and that the IG wiring earth wire goes to the block

bump its not unusual to get ref and rpm errors at the same time.

Reason being as you get huge rpm spikes 16000rpm+ and it triggers rpm error.

You need to redo your CAS wiring.

i have a question. why does the ignition harness ground have to go to the BLOCK. what is the difference between the frame ground. was just wondering.

It can be grounded to the frame if the earthing system in the car is VERY VERY GOOD. And in most cases were people think the grounding in their car is great, it is far from that.

If you have dual 0 guage(32mm) cables grounding your battery to both your chassis and block then i would have no problems grounding the ignition harness to the frame or chassis. But no body ever does. And most ground cables i have seen are not soldered, just crimped.

So microtech ask for it to be sent to the block to avoid warranty issues with people frying x4 boxes from poor earthing.