I'm not sure if thats exactly how it happens, but I'm led to believe under certain circumstances the ecu will in fact shut down the trailing coil if it's receiving bad feedback from certain sensors. Now if this is correct, would it be causing my tach to not work as well? I know the bullet test connector coming off of the trailing coil is not working as well, I tried to hook an aftermarket tach upto it, no dice. So if this is true then I'll be able to track down those sensors and test them out. I've made numerous threads to try and solve my cars issue but everyones stumped

Thanks for looking. Just trying to get my pos working so I can use it instead of it looking like this all the time.

 

Noones??

 

The only time I've ever seen the ECU shut down the trailing coils is when I pull the EGI fuse to de-flood my engine.
It is much more likely if you have intermittent problems with the trailing not working that you have a bad connection, a faulty coil, or a bad ground ( it grounds through itself on its mounting studs). So check that out first, also check for broken or bare wires.

 

I'm at a loss, I've replaced the coil 3 times, and cleaned the area that it bolts down to. I'm not sure how to check the wires, I have a gnarly multi meter and I know how to check for ohms but **** the FSM doesn't cater to newbs haha.

 

If I remember correctly the leading and trailing coils need to be 0.3-1 ohm or something close to that.

 

Thanks buddy I'll remember that. Just found out my multimeter needs to be plugged into the wall dammmat haha.

 

Plugged into the wall? Is it rechargable or is it just old as hell?

 

It's pretty big...it used to be part of my bro's tool set from when he was a nuclear tech in the Navy.

It looks something like this

 

Those bench top sets are handy.

I would get a hand held one though. I have a craftsman one I bought from sears for $30 I use daily at work, and it has all of the nice automotive type settings I need on it. Pulse and duty cycle, etc.

 

Word I'll end up picking up my own. I have someone willing to loan me an OMP so I'm gonna test that out soon. I need to figure out a way to mount the damn thing somewhere besides being ziptied to my intake. I'm thinking and hoping the OMP is the culprit.

 

I Take it you are working on an S5 with a 13b Turbo engine in it?..
You never stated that..so Re-affirm please..you may get more help.(list mods too)Thanks.

 

Haha yeah. Thanks brotato.

car is as follows

S5 NA chassis
S5 TII engine, n370 ecu, boost sensor, maf, USDM TII harness
Bareblocked/No BAC valve/No omp (its plugged in but not used)
All emissions wires depinned and removed from factory harness
Walbro 255lph
Aoex intake/ inlet duct
HKS 3'' downpipe to 3'' straight pipe exhaust

And like 500 other things that have nothing to do with engine work. suspension, cage etc.

 

something like this happens to me at start up. It starts up fine but it sounds and feels like it running on one rotor. I check and replaced the tps and cas along with bot leading and trailing coils. I checked for error codes but got two solid lights that wouldn't turn off.its an s4.

 

Hmm well since its an s4 that eliminates a few things like the omp. Check the maf out maybe.

my problem is killing me softly...one day at a time

 

thanks for the imput. hopr you solve your problem. By the way I like your fc.

 

Sanks bro!

 

Anymore possible input? I've got something planned, new (well proved working) tps and omp and maf on the way to be swapped out.

 

Why don't you go the FUEL AND EMISSIONS section of the FSM and see if the outputs/inputs to the ECU from/to the Trail coils assy match the FSM or not? There's a page or two called CONTROL UNIT or something similar to that.

Trail and Lead coil assy must be bolted to the chassis for them to work, even if it's with a single mounting bolt/stud.

 

I've just gotta figure out a way to test them thats all. my mulitmeter is business and there is no electricity by the car so Im gonna have to pick up a cheap one.

Thanks for chiming in Hailers I was seriously praying you would. Please keep up with this thread, I will report the findings as soon I test them.