Need help from those knowledgeable with AEM EMS V1 systems

[JohnnyTurbo]

I have a V1 in my '96 VR4, it was in the car when I bought it. After buying the car, I had it tuned at IPS and they corrected several items that were wrong in the build that prevented building boost. I was a happy camper with the 400awhp/430 tq with the 15g's, but on the way home the engine "dropped out" 3 or 4 times, with each rime only being for a second and the tach died back to zero each time the engine cut out. I called IPS and Jeff said he never heard of such a thing and to make a note of the conditions if it happened again. Between '08 to 2012 I put 7000 miles on the car and the cut out happened here and there. Sometimes it would happen a few times on an afternoon drive, but then I could take the car out on several trips and no cutting out.

Oct 2012 I was on the BRP in N.C. for the fall leaf tour and the car cut out several times coming up the diamond back loop to Little Switzerland. I was experiencing definite ignition problems where the engine just did not want to run smoothly and it died in their parking lot. I had to trailer the car home and it has been in my pole barn ever since. I called MSD customer support and they ruled out the digital ignition box (DIS-4). SO, anyone have any ideas where to start looking with the AEM EMS? I hooked my laptop to it and the unit seems to be functional, but I am clueless to the workings of the EMS and if it can tell me what is wrong. I have the next 10 days off on vacation and would like to breathe life back into the beast. Any help is sincerely appreciated.

-John

[NOMIEZVR4]

Ive heard its pretty common for the aem boxs to fail...people regularly send them to aem to get repaired. Send it to aem and have them test it.

[mjannusch]

I also had a MSD DIS-4 on my Spyder with the AEM and it never had a problem until I added the DIS-4. Once I put that on, occasionally it would stumble like you describe where the ignition just briefly cuts out and then comes back. A friend of mine has the same setup, same problem. Pretty sure it is something with the DIS-4.

[bradrs]

The DIS used to have problems with heat, and I assume the design is still sensitive to it. Where did you mount it? But to ID whether it is the DIS or AEM, you might want to see if anything else cuts out. Depending on how the tach was wired it could indicate a problem with the AEM.

How did you wire in the MSD and tach wire?

[JohnnyTurbo]

system was in the car when i bought it. It's under the hood and xwire said he quit putting them there due to the heat soak issue. I can pull the dis-4 out of the system, but what would be needed to replace it? I can unbolt and bolt, tear out & replace just about anything mechanical, but the electronics part of these cars is voodoo to me.

[95gto]

system was in the car when i bought it. It's under the hood and xwire said he quit putting them there due to the heat soak issue. I can pull the dis-4 out of the system, but what would be needed to replace it? I can unbolt and bolt, tear out & replace just about anything mechanical, but the electronics part of these cars is voodoo to me.

I strongly recomend contacting Von directly about your car's DIS-4 installation. Depending upon the vintage of EMS that the car has the DIS-4 could have been setup two different ways, and one of which has a more involved uninstallation process.

We quit installing DIS-4's on cars in general as even installing them on the inside of the car does not fix their reliability issues. Von can even recomend the right part to replace the DIS-4 for you. I want to say that the AEM system is the one that works really well but I would confirm that with him.