Autometer Tach on V4 / Nissan VQ30DET Quadcam

[Chris Philo]

Hi, I have a customer with a buggy equipped with a Link V4 attached to a Nissan VQ30DET Quadcam. I need to install a Autometer tach on this system but I have no paperwork or diagrams for this ECU. The Autometer tach needs a negative trigger. Any suggestions?

[Jurgen Biggelaar]

Hi Chris.

The folowing info is assuming the unit is a G1 LEM V4.

• If you have a distributed set up, you use ignition 3 as your tacho output and set up under configuration/Ignition 3 as tacho.
• If you are running wasted spark, all 3 ignition channels will be used up.  In this case the ECU would have to have a small modification to enable the RPM switch as the tacho output (if it's not needed to run anything else)
• All of these options are only designed to run a low level tacho.  You cannot run the tacho if it is a high level FULL STOP.

If none of this suits, you will have to either get a different tacho to suit one of the options above or drive it directly from a coil negative on the actual coil.

 

Jurgen

[Chris Philo]

The markings on the end of the case are: VG30DET D42V4 110703 Is this a G1 LEM V4? It appears to be next to some type of programming port. I have no prior experience with this brand of engine management. Only with HKS and Megasquirt standalone. Where can I get a programming cable and software to see what type of out this has? I have no supporting documents or diagrams for this system. Hooking directly to the coils is a difficult task due to it being coil on plug. The gauge is a #5898 Autometer Phantom 10k tach. Here is a link to the install directions: http://www.autometer.com/productPDF/1185.pdf I believe this tach needs 12v square wave?

[Jurgen Biggelaar]

Hi Chris.

 

Yes definately a G1 V4 LEM, and most definately is that tacho needing a hig level input.  I hear you with the difficulty of making this work with the mutli-coils though, and in all honesty the cheapest solution for you to make this work will be to get a low level driven tacho.  Really it's your best option.

You can get the SerialLink from Link still as they are always stocked, email [email protected] for a price and availability.  For documentation on this ECU, this link should just open the manual on line for you... Click "Save a copy" to put it on your hard drive for future reference.

http://www.linkecu.com/support/documentation/g1-engine-management-documentation/lemv4manual

Jurgen