Troubleshooting Help

anaphe · Post by **anaphe** » Sat May 17, 2008 2:17 pm

Hi Guys,

I have MJ installed in my race car and with (GT3 Road Race) and with the exception of an exploding trigger wheel (stock ford part) that my partner experienced the system has been relatively trouble free.

Last night while doing some testing the car ran flawlessly for a few hours then I bounced off the rev-limiter @ 8400 and moments later the car started to miss above 7000 rpms. The tach swings when this happens.

We are using the TPS but do not use it for load calcs (as this is a race car).

I checked grounds and they all look fine.

Visually checked that the new machined trigger wheel and VR sensor appear to be visually intact.

The coil pack is an Accel unit. Any way to trouble shoot short of replacing everything?

Anthony

Post by **brentp** » Sat May 17, 2008 5:28 pm

Hi Anthony,

First test- let's isolate the problem. Can you repeat the missing behavior if you disconnect the MJLJ and run it at the default 10 degrees?

What are the condition of your plugs? What type of rev-limiting do you have enabled?

anaphe · Post by **anaphe** » Sun May 18, 2008 12:32 am

Hi Brent,

Never thought about running it in default @ 7000 rpm+

Plugs are good. Rev limiting is through MJL set to 8200 RPM.

anaphe · Post by **anaphe** » Wed Jun 04, 2008 3:11 pm

Hi Guys,

Update! We got it working. The car was defaulting to limp home mode.

It turned out to be a component that had separated from the board. Luckily we had a spare box and everything was fine. The piece was rattling around the box.

I think we will silicone the new one on.

Regards,

Anthony

MartinM · Post by **MartinM** » Wed Jun 04, 2008 3:46 pm

You mean:

- all the leads fractured and the body of the regulator was floating around in the case?

- all the soldered connections broke and the whole regulator (including its leads) was floating around in the case?

Some pictures sure would be useful - AFAIK this has never happened before...

I always use a bolt (preferably nylon) with a shakeproof washer, loctite and a nut to hold the regulator down. Mainly for thermal reasons (not really needed TBH) but every little helps....and after all, there's a hole in the regulator and a hole in the board, so I figured I might as well use them!

Post by **brentp** » Wed Jun 04, 2008 6:29 pm

It looks like the unit might have suffered from a very high vibration environment.

Securing the regulator to the board will help in the future, but the processor chip (the one in the middle) might eventually shake loose under these conditions. If you are suspecting high vibration in your application, consider placing some rubber isolating washers between the case and the mounting surface.

anaphe · Post by **anaphe** » Thu Jun 05, 2008 2:48 pm

Hi Brent,

Yes it totally separated and failed above the solder joints on the 3 pins.

The unit is isolated from the body with rubber stand-offs - but this is a race application.

We will use a dab of silicone to secure to the board in the future.

FYI the unit that failed was one that was purchased fully assembled from the site and there was no nylon standoff present. The kit we built as a spare also had no nylon standoff to secure to the board.

Post by **brentp** » Thu Jun 05, 2008 5:33 pm

Thanks for the feedback. We'd recommend still adding a fastener (like a 4-40 bolt) plus silicone for your application.

We have significantly improved ruggedness across the board in our V4 controller with the move to surface mount components- it should be appealing to those running in severe environments.

anaphe · Post by **anaphe** » Wed Jul 02, 2008 3:05 pm

Hi Brent.....is it possible to purchase a new regulator?

I have been unavailable to find one locally here in Calgary.

Anthony
anaphe@gmail.com

Post by **brentp** » Wed Jul 02, 2008 3:30 pm

Email sent.