Coil Packs Fried? JP-8???????
Thread Starter
Senior Member
iTrader: (3)
Joined: Dec 2007
Posts: 827
Total Cats: 0
From: Fayetteville NC
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.
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.
Thread Starter
Senior Member
iTrader: (3)
Joined: Dec 2007
Posts: 827
Total Cats: 0
From: Fayetteville NC
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.
Joined: Sep 2005
Posts: 34,402
Total Cats: 7,523
From: Chicago. (The less-murder part.)
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 **** 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...
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 **** 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...
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
Last edited by mikeflys1; Feb 10, 2008 at 12:16 AM.
Joined: Sep 2005
Posts: 34,402
Total Cats: 7,523
From: Chicago. (The less-murder part.)
Originally Posted by msydnor
Joe, do you know if the coils going out would account for the not strating when hot?
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.
Thread
Thread Starter
Forum
Replies
Last Post
StratoBlue1109
Miata parts for sale/trade
21
Sep 30, 2018 01:09 PM








