As the saying goes: Proper planning prevents piss poor performance. I loaded the .pdf for the MegaSquirt, the LC-1 Wideband, and the Dodge Shop Manual onto my tablet. I printed out the pin reference for all of the engine connectors, and I had various diagrams for the alternator, auto shutdown relay, and of course the MegaSquirt and MS3X.
I ordered an MS3 with the MS3X expansion board from SymTech Labs. If you go this route – I was a little confused as MegaSquirt also has a version 3.0 board. So you have a MegaSquirt 3 processor with a version 3.0 board and an MS3X – lots of M S and 3’s to confuse you. I initially thought the 3.0 board WAS the MS3X… (wrong) Then there is the MS3-Pro, which is basically an MS3 + MS3X + some extras – in a more compact case for more money. As of 2013 this is the newest version of MegaSquirt hardware you can buy.
The MS3X expansion board allows you to do all the cool stuff out of the box like launch control, boost, nitrous, sequential fueling, etc. Full sequential is where you can individually trigger the fuel injector on one cylinder for just that particular intake stroke. Common MegaSquirt setup does a “batch fire” where 2 injectors are opened at the same time. This is okay at full throttle as the time it takes for the fuel to travel down the head, it was already on the next intake stroke at 6,000-RPMs. At idle though you are just spraying fuel onto a closed valve every other time at 700-RPM. Not very good for economy and not that great for a steady idle. In order for it to work though, the MS3X needs to know where your camshaft is.
Standalone Engine Management is not for the faint of heart. I’ve read a lot of forum posts where people become frustrated a few wires into their installation, fry stuff, and blame the people they bought it from. When in fact it was their own lack of understanding when it comes to automotive electrical and tuning. If I were selling and supporting these systems, I would almost have you answer a few questions before being allowed to purchase – but that’s me. 🙂
Last Tuesday after a marathon weekend of mounting seats, belts, lights, etc. I wanted to drive the 2GN rally car to work and get some miles on it before the rally. I start her up in the garage – *blub *blub *blub *blub “Why does that not sound right?” *blub *blub… Sounds like it’s running on three cylinders. I open the hood and the engine is bobbling around pretty good. Rev the motor, drive it around the block, no power, call it done, and park it back in the garage.
In the evening I pull the code P0202 from the computer. This means the “Fuel Injection Circuit has failed on cylinder 2.” Only three things to check and replace. I swap injector 1 and 2 and nothing changes. I test the wiring going to the PCM with a meter and it’s fine. The only thing left is a bad PCM / ECU (Power Control Module / Electronic Control Unit) and I have no idea why it failed. Right now I think it had hesitation issues when I bought it and they got worse. Plus the wiring loom in the front went into the AC compressor, remember?
Wednesday morning, worst nightmare happens – no one has a computer in stock. The last one in the US (you think I’m kidding…) is sent over-night to Tustin Dodge for Thursday. I formulate a backup plan and find one from a junkyard for an automatic (I confirm that it will throw a code, but still run). To add to the drama, you can’t just plug in an old ECU and expect it to work in a car from this century. The dashboard and key module are aware of the VIN number and won’t start without re-programming from a dealer. 😡
On Thursday morning we are all packed on the tow dolly and ready to head to Arizona with a car that only runs on three cylinders. 😐 I drop the 2GN off at the dealership at 7am and go to work. I finally receive a phone call later in the day. The part is in, and the tech I know there (who is a past Neon Owners Club member) has installed the new PCM and was able to re-flash the junkyard one (sometimes it won’t go). The car is running great and we are good to leave for Prescott after work. Now the real adventure can begin. 😀