jumpa56

Hey, I've been having trouble with my LT10S computer on my s513bt. I've installed it, but once car is up to temps of about 86°C into the low 90°'s at a light cruising load, it will stall, sometimes backfire to stall, othertimes just stall. I wait 30 seconds, put my foot on the gas and crank to clear it out, then remove my foot, crank again and it starts back up, thought this might be a coil problem, and i came up with the email below to microtech, along with their reply. First questions, does everything in the email below appear to be correct, and why can't i find any literature on using the trailing coils to determine timing as microtech is suggesting?

Second question, if i'm all set with the above question, could i be flooding my engine out? I haven't had the car to a tuner, i wanted to make sure i wasn't giving someone a can of worms, i don't want it to become a tuners nightmare too. I've searched all around and just can't find anything that fits my problem, hopefully the answers will find me this time around, thanks for any help to anyone who offers. If im missing any info that would help in this diagnosis, just let me know, thanks people.

> Microtech,
>
> In the fall of 2005 I purchased the LT10S computer
> from SpeedMachinePerformance.com. At the time of
> order, I specified that I had a stock S5 13BT motor.
> When I received the kit, the manual had some hand
> written corrections. The ones troubling me now are;
> IGBT was crossed out in the Title, also, the 2 end
> pins on the pin-out are not used (would be L1 and L2
> coils), the tach output is relabeled as L1/L2 coils,
> and all of the coil igniter wires are grey with a
> corresponding colored stripe.
> The schematic matches these corrections, and I wired
> it as instructed.
> Since doing so, I have had the car running, but am
> unable to get any consistancy out of the leading spark
> when trying to time it (timing lock on). The trailing
> spark seems to be firing steady and correctly. I have
> also tried multiple coils with igniters from known
> working cars.
> In my search for answers I came up with more
> questions.
> The LT10S unit is advertised as having built in
> ignition amplifier onboard, yet it is not a direct
> fire unit such as the LTX8? Atleast that is not how it
> is shown to be wired, except in the pin-out before the
> hand written corrections were made.
> If you could enlighten me as to what exactly your
> product is and how it should be installed, or if i
> have done something incorrectly, I would greatly
> appreciate it.
> I currently have the grey wires hooked up to the
> corresponding coils through the mazda factory
> connectors, which go to a coil igniter then to coil.
> Is this the correct way of install with the onboard
> ignition amplifier?


Microtech Reply:

Sounds like you have it installed correctly.
The leading spark is always a little harder to see than trailing , that
is
why Mazda Factory manual states to check timing by trailing lead etc.
The grey wires should go to an igniter as you have it. If you only had
3
grey wires, you seem to have installed it correctly.
The LT10S has an IGBT when used with our X4 box and aftermarket coils.
Tim.