trailing coils no spark
 

have power but wont spark. car runs but only on leading coils. just wondering for any tips. i believe they are wired up correctly.......

Quadruple-check the wiring. We've had just the same problem a few times, and it's always cleared up after the wiring's been corrected. :)

Brandon
BR7 Racing

the wiring is simple.

tan's to +12V IGN PINK

grey/red to pink
grey/black to white

i will double check again ;)

if its correct i think this coil is SHOT

Make sure that the coil's getting power - the Microtech doesn't supply the +12VDC to the pink wire, it expects to see it there (from a source which is not starter-inhibited).

Brandon
BR7 Racing

i have it wired up the same as my leading coils which are firing fine and a friend told me where to get the switched 12V from the diagnostic connector. i just took out the coil and the white wire from the coil side was popped out of the pos mazda connector. pushed it back in. i'm sure that didn't help. the car i bought was wired completely wrong. is there a chance the microtech could be damaged so that the trailings won't fire ? just wondering before i start pulling my hair out. i have to wait to fire up the car again until i get and install the catback on it. the car is simply too loud to even let idle in my driveway with just dp/mp on. that is my next priority. timing is SOMEWHAT near where its supposed to be but must be set

I'm 99.99999% sure it's not the ECU that's at-fault, since we've (and others've) had that exact same problem. As well, it seems that a lot of people get the wires colors mixed up on the gang (4-pin) plug on the T-coil... after a few years white, pink, and grey all look the same ;) If you've got a factory diagram, it might be worth checking your connections against the harness-side colors, as those are a bit clearer. Like I said, check and double-check. :)

Brandon
BR7 Racing

Have you checked it on cranking only or with the car running????

i checked it cranking. i can't leave the car running yet its too loud with not muffler on it. i think the problem might have just been the wire popped out. good to know its not ecu related. that makes me happy. thanks again for the help

Have you put the ECU into test mode and tested it?

Brandon
BR7 Racing

nope still trying to figure out how to get thru everything. i'm a haltech guy so i'm used to that..... this is kind of hard to maneuver

heres some tips to help you out:

1. make sure you have the same gauge or thicker gauge wire for the constant 12V, ecu ground, and ignition harness ground... also sand down to bare metal for the ground.

2. run test mode

3. move the leading igntion output wires to the trailing coils to see if the coils are not at fault

4. test the ignitor... turn the igntion on (engine not running) if the igntion output wires are grounding than the ignitor is fried


good luck!

cool thank you! i will try all of that as soon as i get the exhaust on ;)

the trailing plugs dont spark when cranking as far as i know.

oooh... i still have no exhaust so i still cannot run the car. yay is me. also i need to drain the water from the block today so it doesn't crack in half when it gets cold enough to freeze outside ;)

Ok....here is some funny news.

I bought this Microtech LT8 off of Vosko...and installed it into my TII.

Same problem....no spark it seems. Plenty of fuel, but it just cranks and cranks...without starting. I have not checked for spark yet, but I am almost 100% sure than they are not firing.

I only have one wire running to the +12v ignition source, and that wire runs to the fuel pump relay. Am I supposed to have two wires running to that source?

Any help would be great.....I ran a test on the Microtech and everything says...ok ok ok....no errors or flashing lights...so that means that my wiring is correct...but I may still not have power to the ignition. I am going to pull a leading and see if it is sparking, and then pull a trailing and see if it is sparking...is there anything else I should check.

What if there is no spark? Could it be a +12v problem?

Thanks,
Scott

you must have +12V ignition to the coils via the tan wires i believe it shows it on the wiring diagram. i did the same thing at first..... get a test light and you will see easily if you coils have power

I have power going to the leading and trailing coils. I have spark on just the leading though...the trailing coils are dead....no spark. The car will not start either, and I thought it would start with just the leading firing?

I only have one wire running to the +12v ignition source, and that wire goes to the fuel pump relay. But yet all my coils have a solid +12v. Did you ever get your car running good with this LT8? I have been reading on here and I read alot about the CAS and it being grounded and whatnot...also something about the tach wire being Yellow, not White like the manual says.

I am lost as to what to do....she simply cranks till she floods and never starts. I have brand new spark plugs in it as well. Any help would be great.

What pink wire is supposed to have a +12v ignition source? And does mine already have one since I have power with the key on at the coils?

Scott

the car started,ran and idled with the LT8, i never got to actually check trailing spark while it ran because it was too obnoxiously loud.....one idea i have is possibly the CAS connector is not getting a good connection. with ignition on if you spin the cas outside of the front cover you should see the spark plugs fire. started the car a few times. someone else posted on here that you won't see the trailings fire while cranking only while the car is actually running....... i'll try to think of some more info but yeah the car will start with just leadings firing

Ok....got her to start just a minute ago...but I had RPM errors because of that White/Yellow wire mixup on the trailing coil wiring harness I believe.

I just had to unflood it again and ATF her and she finally fired up and smoked a ton...but the car was idling at some incredibly high amount...not sure since I had no tach...but I would guess about 3000-4000rpm pretty easily if not higher. I think my throttle cable is just too tight...since prying up on the gas pedal it went down some, but it still was way up there in RPM''s.....do I simply move the white/yellow connector around....will that give me my tach back?

Okay. We are absolutely sure the Trailing Plugs dont spark when cranking? I'm experiencing simular problems right now. I put a light to the Trailings and I got nothing when I attempted to start.

I put a light on mine once it was running to check timing on the trailing and I could not even see the red mark.....I think my trailing timing is 180 degrees off from the looks of it. Can anyone verify that they can or can not see their red mark? I got my Leading timing set right at 5ATDC...but I can't get the trailing to time at all.

I can guarantee the Trailing Plugs don't spark awhile cranking.:)

I proved it with a spark tester an scope. :D

Ahh sure, take the credit. Don't forget whos car this was determained on.:)

*semiside note* I just remembered how significantly amplified the Leading Spark Plugs were when we tested them. Quite a difference, considering the Crane Cams Ignition Box was wired to them. Like night and day.