Stuck at the Store: Building a MegaSquirt Sled
Joe Angell
This one will be brief: I went out for groceries, and when I stopped at the store the engine was revving high at around 2000 RPM. When I turned the car off, it wouldn’t start again. After doing a bunch of tinkering I called AAA and got it towed home.
When I plugged the laptop in, I found I couldn’t connect to MegaSquirt. After about 10 minutes and two laptops, I finally realized that the problem was very simple: the DB38 cable had come off. Apparently I didn’t screw it in last time I removed MegaSquirt, and it finally worked its way off the connector.
It’s a real pain to get that screwed in, especially if you somewhat frequently remove MegaSquirt from the car. I decided to build a sled that would hold MegaSquirt in place while also keeping the cable locked in. This had the bonus of avoiding the need to screw down either MegaSquirt itself (which is a bit fiddly) or the cable.
I designed the sled in MODO. At the front is a lip that the front of MegaSquirt slots into. At the back are two pegs that go through the screw holes on the back of MegaSquirt. At the far back is a brace that keeps the cable from falling out of the connector. The sled itself is bolted to the electronics tray.
To install MegaSquirt, you plug in the DB38 cable and the MAP hose, tilt the nose of MegaSquirt under the lip at the front of the sled, then the back is laid down over the pegs with the DB38 held in place by the brace on the back. Nice and simple. The stock wooden cover keeps anything from bouncing up and coming loose.
So far it’s worked well. It’s very easy to remove MegaSquirt and the cable is secure.
The uninstalled sled next to MegaSquirt. The bolt holes are recessed so that MegaSquirt can sit flush on top.
The nose is tilted down under a lip before laying down on pegs that keep it from shifting around.
The back showing how the cut out for the MAP hose and the DB9 cable, plus the posts that hold the cable in place.
MegaSqurit installed on the sled on the bench.