hi, take a look at this wiring diagram for an sm4 unit.

gonna be used on a yb-engine.
-std sensor at crank
-autronic hall-sensor at cam/distributor
-autronic ACT-sensor
-standard water temp sensor
-standard TPS
-4 1200cc injectors
-electronic boost valve
-lauch control programmed over output 1, pin7.
-MSD Ignition 8245 Blaster coils.

is this the way to do it?



comments?

 

Looks fine to me, but I would hack two lugs off the crank sensor wheel as the Autronic works best on 2 pins typically.

You'll LOVE the boost control if you get it setup correctly with a map of boost value referenced against RPM/TPS, it just drives SO well like that

 

yeah, forgot to say that there's only 2 lugs on the pulley.

just getting the car started now, will go on a Rototest in a month or so.

 

Ah, you already knew about the 2 lugs

Im sure Rod might have some info on the multicoil bit of it too, Ive only used it on coilpack so not positive on exactly how the indifvidual coils go without looking at the manual, but you're certainly in the right ballpark with the rest

At least you worked out the 1342 thing on the injectors, loads of people think the 1234 on the ecu refers to cylinder order not firing order!

 

How are you running the coil setup? 4 coils configured for wasted spark?

 

He can run either wasted spark or one fire per cylce.

He has them ordered (if you look closely under the coils) as 1342 accordingly, as opposed to simply 1/2 so he is I assume planning on firing them individually.

 

I can see the numbers under the coils, shouldn't they be set to fire in the same order as the injectors? I've followed the lines and they seem to be firing out of sequence, unless i haven't grasped something here?

I have the firing order of the coils in that diagram as 1-4-2-3?

 

Yes, you are correct, I'd imagine thats just an error in how he drew the diagram rather than how he was going to wire it though as he got it right on the injectors.

Well spotted, I hadnt noticed that when I had a look at it so your eyes are better than mine (must be true what they say about wanking making you go blind )

 

Correct!!

I have told the guy this via a PM . I make these looms on a regular basis & noticed it straight away, didnt really want to contradict Chip so did it via PM.

 

haha, just a small typing error there changed it now.

also sent the coil grounds to pin22, sensor ground, as adviced by Rod.

otherwise it's okay?

is the launch activated when grounded?

 

Yes, I usually allocate HSI 2 (pin 24) for that task. With a wheel speed sensor it can be done automatically .

 

okay, cool.

will take it over a switch as it will only be used when something a bit stronger than an old t5 will be mounted

 

Cool, i wasn't trying to catch anyone out, just wondering if i was getting something wrong, i shall be building a loom for my SM4 soon so this subject is somehting i'm quite interesting

 

Can i just confirm that the coils should use the same firing order as the injectors when using individual coils for each cylinder?

 

Yes rick they should.