Installer Errors
Here's where we come clean. Did this installation go as smoothly as it might appear? Absolutely not. But that's not because the MegaSquirt is a difficult system to master. Granted, this is not a system for the entry-level car crafter who barely knows one end of a screwdriver (or injector) from the other. But neither is this system overly difficult. The difference is that with this budget-based system, the designers are letting you do more of the work. What do you expect for $225?
We did have difficulties, but almost all of it was self-inflicted. The reason the engine was tested on two different dynos is that during our original test at Westech, we had engine-related problems that complicated our attempts with the carbureted baseline. Eventually we discovered that in earlier work on this engine I had placed a solid lifter on the intake lobe of Number 2 cylinder that kept the intake valve open and killed the power. Once we fixed that problem, we ran into trouble getting the injected version to run. We discovered an intermittent connection problem with the chip that showed up when we checked operation with the stimulator. We replaced it with a spare chip Tim had thoughtfully purchased for $10. However, the engine still wouldn't run properly and we ran out of time. Later, Tim discovered that we had forgotten to load the base fuel map onto the second chip!
Dyno-testing at Duttweiler looked like it would be a cakewalk, and at first the engine fired right up and ran well with the base VE map. But suddenly, the engine would run rough, misfire, and quit. Since MegaSquirt doesn't control spark, our setup included an MSD billet distributor and an MSD 6A controller. Since the MSD box does emit electro-magnetic noise, we thought that might be the problem. Eventually, we traced the intermittent problem to the white wire on the MSD box occasionally grounding out to the tray on the dyno! Once we insulated that wire, the engine ran like a champ!
The point of all this is that only once was there a problem with the MegaSquirt and that was quickly rectified. The rest of our problems were self-inflicted, yet we still kept thinking that the source of our frustration was the MegaSquirt computer. The lesson here was that we tend to blame the stuff that we don't understand, when usually it's some dumb mistake that we've made that has nothing to do with the black box. This is a lesson that was hard-earned and worth remembering.
Parts List
The following is a list of the parts we used to build the MegaSquirt system and run it on the engine. It's a little confusing, because you purchase Printed Circuit Boards (PCBs) from MegaSquirt, but the rest of the electronic parts are from a separate company called Digi-log. It's all on the MegaSquirt Web site. Prices for all MSD and SLP products were taken from www.summitracing.com.
Component Manufacturer PN Price
ECM board MegaSquirt MSPKIT $120.00
Digi-key parts Digi-log - 51.40
Relay board kit MegaSquirt RELAYPCB 15.00
Relay board parts Digi-log - 38.91
Stimulator box MegaSquirt STIMPCB 20.00
Stimulator parts Digi-log - 21.92
Injectors, 36-lb/hr MSD 2018 421.00
Injector harness MSD 2400 15.00
Coolant sensor MSD 2310 12.00
Air inlet sensor MSD 2320 17.00
Oxygen sensor, heated three-wire MSD 2330 73.00
Bung for oxygen sensor MSD 2335 19.00
MSD 6A box MSD 6200 150.00
Used TPI manifold pre-owned - 200.00
Misc. wiring and parts - - 50.00
Performance-tuned runners SLP 20002 260.00
Gasket set SLP 20030 20.00
Total:
$1,504.23