If you’ve ever had admin access to a server or rooted a phone, getting access to every single mode and operation of your engine feels exactly the same. First you go through some trick BS where you have to remove a battery and USB and networking cables are everywhere. Someone grants you access to the machine or you run a sketchy .bat from some internet shareware site, and next thing you know, you have total and complete control of your hardware. It feels great, but your euphoria quickly turns to panic as you start clicking dialogs and checkboxes. “You are about to change the permissions on sub-folders – are you sure?” “You are about to flash new firmware this may brick your device – are you sure?” “CAUTION! Anti-lag is very hard on your turbo and engine. Use at your own risk.” 😛 Then you start to forget that you dropped a script in /usr/bin that causes issues with a backup, or selected PID air-fuel correction and went off to tune the VE table. Completely the same – so be careful as you just rooted your car.
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.
Let me start by letting you know that this article is going to be very technically oriented towards fixing a 2003 Dodge Neon. I’m sure some of the info will be helpful for any car built in the 21st century, but you may want to skip over the gritty details. This article will also reveal the complicated way cars check for fuel leaks and explore some of the huge frustrations of modern emissions testing. Ready to unravel a mystery? I recently learned so much about the Chrysler EVAP system that I wanted to share – in plain English – what I went through, and what I learned.
You: “I have code P0440 – what should I do?”
Every car mechanic: “Replace your gas cap!” Continue reading →
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. 😀