Warning! MPI Tuner + J&S Safeguard

LinuxRacr

Contributor
:
2001 Mazda MP3
To anyone planning to utilize the J&S Safeguard in conjuction with the MPI Tuner, you need to know the following:

The 12v+ (Red Wire/Pin 4) on the J&S 2-Channel UltraSafeguard needs to be hooked into the Red wire(with the white stripe) that goes to power the fuel pump, and powers the Turbo Module (blue wire on the Turbo Module hooks into this wire). If you don't power your J&S with this wire, then you will fry coils when you have the key turned to on, and the engine NOT running.
 
Oh, it isn't that bad. . .coils are $12.45 / each.

So, I don't really understand why there would be a problem (I believe you, I just don't understand). The J&S will not generate a signal, so even if it is on, it should not cause the coils to "energize". Did you figure out why it did this, or just the way to "avoid it" (Which is good too mind you. . .I'm just curious). Basically, this only affects a couple of us. . .but more down the road I'm sure.
 
Good thing I had extra coils up in the attic from my FS-ZE that I had forgotten about. (thumb)

Here's my explanation:

Let's look at the 1st fact. The power wire that goes to the fuel pump (Red with white stripe) only gets power as you are cranking the engine. If you only turn the key to position II without the engine running, you will not get a +12v on this wire. When you crank the engine, this wire powers up right before the engine starts turning over. If the engine does not start, the wire goes dead again.

2nd fact. The J&S is hooked directly to the coils in between the ECU/MPI and the coils. When hooked to the key on power source that it was on previously, it powered up when the key was turned to the II position, without the engine running. I then when and put my hand on the coils, and they would get hot without the engine even running. I killed the power. Somehow the circuit was being completed when the J&S was hooked to the other power source. As soon as I put it on the same power souce as the fuel pump wire and turbo module, I was able to turn the key on to the II position, and touch the coils. They were cool to the touch.
 
have you had the MPI for a while and installed and used and not had this problem? or is this the first time you've had the MPI and the JandS or so forth? When did you get the JandS?
 
Well, if this worked BEFORE you installed the MPI, then I would not suspect that its the JnS' fault, but an issue that the MPI caused.

IIRC, you have been running the JnS for some time correct? and you installed the MPI recently, and this is when the coils burned? Then you changed from your origional install of the JnS to compensate for the coil burn after the MPI install?

Im not being a dick to ya Linux, you know that. Im just trying to get all the facts for this issue straight for anyone else who might be thinking of running a similar setup. :D
 
Thanks for the info linux..this will be very helpfull for someone like myself..who don't want a full stand alone..by having the J&S parallel to the mpi is like having a stand alone!

(rockon)

Chas
 
boostisgood said:
Well, if this worked BEFORE you installed the MPI, then I would not suspect that its the JnS' fault, but an issue that the MPI caused.

IIRC, you have been running the JnS for some time correct? and you installed the MPI recently, and this is when the coils burned? Then you changed from your origional install of the JnS to compensate for the coil burn after the MPI install?

Im not being a dick to ya Linux, you know that. Im just trying to get all the facts for this issue straight for anyone else who might be thinking of running a similar setup. :D
It isn't the J&S (at least not by itself). I had the J&S installed for quite awhile before the MPI and never had a coil problem. Apparently something happens when you put the two of them together. But there was also a coil problem with the MPI by itself (which has been resolved). So draw your own conclusions.
 
Thanks Bavis for clearing that up. Great info Linux and Beavis. Im glad that the issue is being resolved, and all will work out for future owners of these producst. :D
 
boostisgood said:
Im not being a dick. :D
Thanks for showing your heart felt concerns about the MPI Tuner and its growing user base. As with any product that Modern Performance Inc. sells you never need to worry. We always stand behind our work and products. Also I would like to thank Patrick for being able to do some testing with the J-S and the MPI tuner. His car is just one of the growing number of Proteges running the MPI Tuner. Now more then ever the MPI Tuner is becoming the number one chocie for tuning the Protege.


Thanks again


Later...........Nick
 
boostisgood said:
Well, if this worked BEFORE you installed the MPI, then I would not suspect that its the JnS' fault, but an issue that the MPI caused.

IIRC, you have been running the JnS for some time correct? and you installed the MPI recently, and this is when the coils burned? Then you changed from your origional install of the JnS to compensate for the coil burn after the MPI install?

Im not being a dick to ya Linux, you know that. Im just trying to get all the facts for this issue straight for anyone else who might be thinking of running a similar setup. :D

Accually, I didn't change my original install of the J&S at all. The J&S just became the "engine side" of the equation. The part where cut the ignition drive wires, and put the MPI Tuner in series...one side goes to the stock ECU, and one side goes to the engine. Instead of the wires being fed directly to the coils, they are fed into the J&S, and then out of the J&S to the coils.
 
MPNick said:
Thanks for showing your heart felt concerns about the MPI Tuner and its growing user base. As with any product that Modern Performance Inc. sells you never need to worry. We always stand behind our work and products. Also I would like to thank Patrick for being able to do some testing with the J-S and the MPI tuner. His car is just one of the growing number of Proteges running the MPI Tuner. Now more then ever the MPI Tuner is becoming the number one chocie for tuning the Protege.


Thanks again


Later...........Nick
No problem Nick. I am the "O.G." Guinea Pig up in this site!
 
Quick just to make sure. . .
You need the red wire with the white stripe.
(There is also a white w/ red stripe and a red w/ black stripe right next to it.)

Also, you are running the coils in this manner.

ECU - MPI - Turbo Module - J&S - Engine
 
RED WIRE WITH WHITE STRIPE!

YOU can also find it beneath the cup holders on the left..

Chas
 
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