The once and 4 all JP8 topic! - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


E-Manage Post your questions about greddy e-manage installation and tuning here.

Reply
 
 
 
LinkBack Thread Tools
Old 08-19-2007, 06:51 AM   #1
Junior Member
Thread Starter
 
Join Date: Aug 2007
Location: The Netherlands
Posts: 49
Total Cats: 0
Default The once and 4 all JP8 topic!

Well I'm getting very confused. Should I or should I not use the 12V setting of the JP8 on my EMU. I see very different settings. Sometimes they warn that the 5V setting would fry the coils. Fot example:

Quote:
Originally Posted by badboy88000 View Post
your miata is a 99 right? set jumper 8 to 2-3, 12V system. 99 miata's run on a 12V system. if you use the 5V, youll fry the coilpacks. i was lucky to buy the EMU used, coming from a honda guy, he used the 12V system, and i didnt bother to change my jumper on that, but the car runs perfectly (besides the fans not turning on) read up on that, theres somewhere on yahoo groups about wiring up op-amps to make everything better.
But another member told me this:
Quote:
Originally Posted by Joe Perez View Post
There was a wonderful thread about this a while back, but unfortunately all that was lost in the Great Accidental Purging of Two Weeks Ago.

The practical upshot was that I verified with an oscilloscope that the ignition trigger level on the 1.6 engine was in fact 5 volts, and have run my EMU at that setting for roughly a year with no problems. Someone else interjected that perhaps the 1.8 engine used a different signalling level owing to its different ignitor design, however nobody ever volunteered the use of their NB to me so that we could scope out the ignition on one of those. At the end of the whole thing, we all agreed that we had absolutely no idea what was going on, and so instead we got drunk.
These are the settings of another EMU user on a '99 Miata:
Quote:
This is Emilio's Jumper settings...

J1 O
J2 O
J3 O
J4 O
J5 O
J6 O
J7 1-2
J8 1-2 (=5V)
J9 1-2
J10 O
J11 O
J12 O
J13 O
J14 1-2
J15 1-2
J16 O
J17 O
J18 O
J19 O
J20 O
Good advice form Joe Perres:
Quote:
JP1 through JP4 = open (no jumper)

JP7 = 1-2

JP8 = 2-3 (there is some confusion here. On the 1.6 it is 1-2, but some 1.8 owners have reported damaging their coils on this setting.)

JP9 = 1-2

JP11 through JP14 = open (no jumper)

JP15 = 1-2

JP18 = open (no jumper)

JP19 & JP20 = 1-2

The other jumpers do not matter for a Miata engine.
And so on...
So what is the best jumper 8 option for a MK2 1.8?

Last edited by MX5Kuro; 08-19-2007 at 04:45 PM.
MX5Kuro is offline   Reply With Quote
Old 08-21-2007, 01:07 AM   #2
Senior Member
iTrader: (7)
 
Join Date: Jul 2007
Location: Milpitas, CA
Posts: 1,057
Total Cats: 1
Default

i was confused too, when i first installed the EMU. i thought that it was originally 5V, when i did install it cause i thought i changed the jumper setting until i opened it a couple of nights to go to find out i didnt change it. The setting was under 2-3 for jumper 8, and my car drove and ran fine. i would rather not find out what would happen if i changed it to 5V.

my car is a 99 M2 miata..

another person in a yahoo group for the EMU found lots of problems with our cars, particular to the sensors. IM STILL HAVING PROBLEMS TRYING TO MAKE MY GOD DAMN FANS WORK!

my jumper settings on the fan are also as follows
JP13 OP
JP14 OP

someone had a detailed explanation about why our fans wouldnt turn on either if we had JP13 set to 1-2. i followed this, but i still havent been able to turn on the fans. Someone also said to use the HN_WT-2 water sensor to make the fans work, but ive tried it, and to no avail.
Marc D is offline   Reply With Quote
Old 08-21-2007, 09:56 AM   #3
Junior Member
 
Join Date: Jul 2006
Location: Torino, Italy
Posts: 99
Total Cats: 0
Default

I have a '99 1.8 NB Italian Spec.
My JP8 is 1-2 since years and it's working perfectly, like anything else (fans, fans control, auxliary output, analog output, wt, at, o2 clamp, water injection etc..) except knock and ignition advance monitor.

Look carefully on the emu circuit board at the jp8 position. The installation manual shows wrong position of pin 1!!
jhoexp is offline   Reply With Quote
Old 08-21-2007, 10:04 AM   #4
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,689
Total Cats: 99
Default

From the title, I thought you were trying to run jet fuel or something
JP = Jet Propellant, JP8 is the blend used in most USAF jets.
Ben is offline   Reply With Quote
Old 08-21-2007, 12:27 PM   #5
Senior Member
iTrader: (7)
 
Join Date: Jul 2007
Location: Milpitas, CA
Posts: 1,057
Total Cats: 1
Default

could be different from american spec cars?
Marc D is offline   Reply With Quote
Old 08-21-2007, 01:12 PM   #6
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,315
Total Cats: 1,913
Default

I keep making this offer, and I keep getting no takers. If anyone with a 1.8 in the So.Cal area wants to volunteer to come to my place in Carlsbad, I will happily scope your ignition system and you can become known as the hero who finally helped to settle this once and for all. Doesn't matter if you have an EMU or not, so long as the stock ECU and stock ignition coils are still in place.

Ideally, I'd like to test a '94-'95, a '96-'97, a non-COP NB, and a COP NB.
Joe Perez is online now   Reply With Quote
Old 08-21-2007, 03:57 PM   #7
Junior Member
Thread Starter
 
Join Date: Aug 2007
Location: The Netherlands
Posts: 49
Total Cats: 0
Default

Quote:
Originally Posted by Joe Perez View Post
I keep making this offer, and I keep getting no takers. If anyone with a 1.8 in the So.Cal area wants to volunteer to come to my place in Carlsbad, I will happily scope your ignition system and you can become known as the hero who finally helped to settle this once and for all. Doesn't matter if you have an EMU or not, so long as the stock ECU and stock ignition coils are still in place.

Ideally, I'd like to test a '94-'95, a '96-'97, a non-COP NB, and a COP NB.
I would if I could, but then I have to cross the ocean...
MX5Kuro is offline   Reply With Quote
Old 08-21-2007, 05:44 PM   #8
Junior Member
 
Join Date: Jul 2006
Location: Torino, Italy
Posts: 99
Total Cats: 0
Default

Quote:
Originally Posted by badboy88000 View Post
could be different from american spec cars?
I don't think so.
I believe that all the jp8 thing is caused by the stupid greddy manual that reverse the position of the pin 1 on the jumper.
jhoexp is offline   Reply With Quote
Old 08-21-2007, 09:23 PM   #9
Junior Member
 
Join Date: Apr 2007
Location: Melboure australia
Posts: 171
Total Cats: 0
Default

Hey Joe, can you tell me how i can scope the ignition system to find out......

otherwise its going to be a long drive for me
sprx3 is offline   Reply With Quote
Old 08-22-2007, 11:31 AM   #10
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,315
Total Cats: 1,913
Default

Quote:
Originally Posted by sprx3 View Post
Hey Joe, can you tell me how i can scope the ignition system to find out......
First, get an oscilloscope. Just about any unit will do- my personal rig is an old 20Mhz B&K.

Set the channel A input to DC coupled, 2 volts / div (appx) and set the Y-POS to offset the trace down to the lowest division on the scale. (On some scopes you'll have to put the trigger into continuous while doing the offset adjustment). Set the trigger to channel A rising edge, at about 3 volts or so. Start with the timescale at maybe 10msec/div. You'll have to tinker with that one.

If you do not yet have an EMU/EMB installed: Disconnect the plugs going to both coils (or to the igniter on a 1.6) and attach the probe to the trigger line of one of them. I believe that these wires are brown and brown/yellow on all years. We need to measure the signal without the load of the igniter which, on a 1.6 anyway, seems to be fairly low impedance and really uglifies the trace.

If you already have an EMU installed, simply probe between the ECU and the EMU. Ground the probe wherever convenient.

Crank the engine, and observe the scope. Adjust the timescale and trigger until you can see both the high-level and low-level events. I believe that the ignition pulse is active-high. Since the load is disconnected, you should have a nice clean shelf on each ignition event. Determine the magnitude of the high-level trace by reading the scale, and you have your ignition trigger voltage.
Joe Perez is online now   Reply With Quote
Old 09-05-2007, 09:48 AM   #11
Newb
 
Join Date: Jan 2007
Location: Bavaria / Ger
Posts: 15
Total Cats: 0
Default

Give it any news about this problem?
ladiarosa is offline   Reply With Quote
Old 09-05-2007, 04:47 PM   #12
Junior Member
Thread Starter
 
Join Date: Aug 2007
Location: The Netherlands
Posts: 49
Total Cats: 0
Default Voltmeter

Well I tried to measure it with a standard voltmeter and it showed less than 5 Volts. So I take my chances at 5V until proven otherwise. It's running beautifully in the meantime.
MX5Kuro is offline   Reply With Quote
Old 09-05-2007, 05:09 PM   #13
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,315
Total Cats: 1,913
Default

A voltmeter is useless for measurements like this. The signal changes more rapidly than even an expensive DVM like my Fluke 77 can measure.

For what its worth, I remember a while back seeing a little gadget that plugs into a Nintendo Gameboy and turns it into a 4-channel DVM/scope. Very primitive interface, but it seemed like the hand-heldedness of it would make the system quite versatile. Alas it is no longer available new, but I thought it might interest some folks. Here's a link to the site that originally carried it, and still provides software support: http://www.educatingmario.com/
Joe Perez is online now   Reply With Quote
Old 09-06-2007, 02:18 AM   #14
Junior Member
Thread Starter
 
Join Date: Aug 2007
Location: The Netherlands
Posts: 49
Total Cats: 0
Default

Quote:
Originally Posted by Joe Perez View Post
A voltmeter is useless for measurements like this. The signal changes more rapidly than even an expensive DVM like my Fluke 77 can measure.

For what its worth, I remember a while back seeing a little gadget that plugs into a Nintendo Gameboy and turns it into a 4-channel DVM/scope. Very primitive interface, but it seemed like the hand-heldedness of it would make the system quite versatile. Alas it is no longer available new, but I thought it might interest some folks. Here's a link to the site that originally carried it, and still provides software support: http://www.educatingmario.com/
I knew it's not the most accurate way of measuring it, but would't it even measure a spike more than 5V? I've read a lot of posts and my guess at this moment it is most likely 5V and the "12V" setting would be a faulty 5V setting as mentioned above. But again it's the most aducated guess at this moment, but nevertheless still a gues. So I'll stick to 5V until proven otherwise.
MX5Kuro is offline   Reply With Quote
Old 10-03-2007, 03:37 PM   #15
CrashHouse
Guest
 
Posts: n/a
Total Cats: 0
Default

Any news on this subject?
  Reply With Quote
Old 10-11-2007, 05:42 PM   #16
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,315
Total Cats: 1,913
Default

Resurrecting an older thread here, because we have some new data.

Reverant over on M.net has scoped the ignition signals on an '01 and determined that the signal level from the ECU to the ignitior is in fact 12 volts. Whether the same is true for the '99-'00 or the 1.8 NAs is still not known with certainty, however taken together with the earlier reports of ignition trouble on these cars it does strongly suggest that 1.8 engines in general may use 12v ignition control.
Joe Perez is online now   Reply With Quote
Old 10-11-2007, 08:15 PM   #17
Senior Member
iTrader: (7)
 
Join Date: Jul 2007
Location: Milpitas, CA
Posts: 1,057
Total Cats: 1
Default

great that its been somewhat "confirmed"
Marc D is offline   Reply With Quote
Old 10-11-2007, 08:54 PM   #18
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,315
Total Cats: 1,913
Default

Well, I'm still waiting for somebody with a 1.8 NA to come out to my garage in Carlsbad so that I can lay a 'scope probe on it and settle this once and for all. But so far, no takers. C'mon people, I know that several of you live in the San Diego / LA area. Don't you want to become known as the dude who finally stepped up and provided the answer to The Ultimate Question.
Joe Perez is online now   Reply With Quote
Old 11-05-2007, 06:32 PM   #19
Junior Member
iTrader: (2)
 
Join Date: Nov 2006
Location: N/A
Posts: 360
Total Cats: 0
Default

Im getting one of those cheapo usb o-scopes by the end of the week so i'll be able to confirm for 99-00's.

Last edited by mikeflys1; 11-08-2007 at 06:01 PM.
mikeflys1 is offline   Reply With Quote
Old 11-08-2007, 06:01 PM   #20
Junior Member
iTrader: (2)
 
Join Date: Nov 2006
Location: N/A
Posts: 360
Total Cats: 0
Default

Got it today and mine was 12v also...




I think the difference between the two graphs is with the first one i just grounded to the door hinge and the second i went right to the battery.
mikeflys1 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Using AFR instead of Volts with AEM Wideband in AFR Target Table Joe Perez MEGAsquirt 55 03-24-2014 11:16 PM
Emu, 2004 msm & cel p0351/p0352 hershann E-Manage 3 09-07-2008 08:42 PM
Jumper Settings & EMU hershann E-Manage 0 08-31-2008 06:24 AM
Quote of the day. Not m.net related! Braineack Insert BS here 15 07-29-2008 03:13 PM
change topic title Hakan Front Desk 8 09-17-2007 01:43 PM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 01:05 PM.