Miata Turbo Forum - Boost cars, acquire cats.

Miata Turbo Forum - Boost cars, acquire cats. (https://www.miataturbo.net/)
-   E-Manage (https://www.miataturbo.net/e-manage-10/)
-   -   Coil Packs Fried? JP-8??????? (https://www.miataturbo.net/e-manage-10/coil-packs-fried-jp-8-a-16811/)

msydnor 02-09-2008 06:02 PM

Coil Packs Fried? JP-8???????
 
Been having issue with my car not starting when hot. (2004 MSM) with EMU. Wont start at all now. I'm starting to think I fried the coils. I had JP-8 set on 1-2 which is 5 volt. From looking around some more, looks like there is question on which it should be. How do you know if your coils are gone? I unhooked the EMU and still no luck. Thoughts.

Braineack 02-09-2008 06:09 PM

if your coils saw a constant 5v they are most liekly dead. easy test is pulling one plug, laying it next to a ground (like the engine hoist point) and trying to crank. if you don't got spark, you most likely burnt out the coils.

msydnor 02-09-2008 06:32 PM


Originally Posted by Braineack (Post 211871)
if your coils saw a constant 5v they are most liekly dead. easy test is pulling one plug, laying it next to a ground (like the engine hoist point) and trying to crank. if you don't got spark, you most likely burnt out the coils.

So guess I should have been on 12 volt....EMU has been set to 5 volt for almost 2 weeks. Would thay explain why it wouldn't crank when it gets hot?

Braineack 02-09-2008 07:49 PM

i dunno much about e-manage, sorry. i just know if a 5v supply was given through the trigger outputs to the coils it would kill them fairly instantly.

msydnor 02-09-2008 08:31 PM

I had heard about coil pack getting fried with Emanage, but thought I had done the appropriate research to determine if my MSM was 5 or 12 volt. After the fact, I guess my research efforts were flawed.

Joe Perez 02-09-2008 08:57 PM

Brainey, they weren't seeing a constant +5. The jumper in question (JP8) determines whether the active high voltage (momentary) is +5 or +12.

There was a lot of debate on this about a year ago. Emilio and others said that, despite the instructions, you needed to set the ignition trigger voltage to +12 or you'd fry your coils. I went out and put a scope on my ignition trigger lines however, and determined that the stock ECU output a +5 signal to trigger the igniter.

Further research revealed that all the nay-sayers had 1.8 cars. So a few people scoped the ignition trigger on their 1.8s, and lo and behold, those cars all used a +12 trigger.

So the general rule for EMU seems to be +5 for a 1.6 and +12 for a 1.8. Nobody had fried any coils in this configuration so far as I know.

This puzzles the shit out of me because as far as I know, all the MS users are using the standard +5 pullup, and I haven't heard of any 1.8 users killing their coils yet...

msydnor 02-09-2008 09:07 PM

Joe, do you know if the coils going out would account for the not strating when hot?

mikeflys1 02-10-2008 12:05 AM

I ran my 99 for a few weeks on 5v before i scoped it and changed to 12v and it didnt seem to matter either way. The actual signal scoped between 9 and 9.5v so maybe the 1.8 coils just have a pretty wide tolerance.....or i was just lucky :)

Joe Perez 02-10-2008 12:04 PM


Originally Posted by mikeflys1 (Post 212002)
The actual signal scoped between 9 and 9.5v so maybe the 1.8 coils just have a pretty wide tolerance.....or i was just lucky :)

This, I believe, is due to load. On my car, it was a sloped signal that got up to about 4v. When I disconnected the igniter and measured the trigger line unloaded, I got a solid 5v square wave.

Originally Posted by msydnor
Joe, do you know if the coils going out would account for the not strating when hot?

Honestly, I have no idea. I don't truthfully even know whether it was the coils themselves or the integrated igniter that was breaking down.

MX5Kuro 02-10-2008 05:04 PM

12v
 
I'm driving with the 12v setting for some time now without any problems. The MSM is a 1.8 BP-ZE with modified internals so it's my educated guess that you should use te 12v setting too.


All times are GMT -4. The time now is 12:42 PM.


© 2024 MH Sub I, LLC dba Internet Brands