Im waiting to hear back form megasquirt now. I have done a little research about them but I havent had much luck with people who used then in the 2nd gens. How does a system like this work? I install the computer they send me, record the data, and how do I create the "tune"?

 

Not sure if your truck is using an OBDII system, but if you are going to use anything other than the factory PCM(JTEC?), the new ECU/ECM/PCM will need trans controls or be piggybacked to the PCM. If you want to retain the SFI, MSIII Pro will be needed, which is pretty expensive, and still would need a separate trans controller.


For OBD I, there are some decent options, if you can figure out a way to use an alternate ECM to control the 46RE trans, a GM ECM like the '7427 could be used. Ive looked into that but the 46re trans does not utilize as many shift solenoids as the 4L60E, so im not sure if a resistor could be used in place of a shift solenoid. HeyYou mentioned tuning his F body, probably the '165 ECM or '7730, and burned lots of EEPROMS. Moates has some nice hardware that doesn't included burning chips, but flash and drive.




To circle back on MS, there are tutorials all over youtube....

 

My truck is OBD1, which im not sure if that makes things better or worst! Im really looking for the most straight forward and easy to instal system. I dont have any formal education in mechanics and this is my first build, which has turned out to be a lot more expenssive and involved than i originally thought. If I can get this truck to run decent and not stall ill be pretty happy.

Also the megasquirt systems are universal correct? As in they do not only fit in one specific vehicle.

 

Unless you purchase one of the PnP systems, all other MS systems are universal. To add, an ECM/ECU/PCM(etc) doesn't care which engine it is attached to, as long as it has the correct feedback sensors. For example, I installed a GM ECM on my old Fox 5.0 mustang, the ECM used was originally OEM on an early 90's Sunbird V6, but the ECM was also used with TPI F bodies, so a base tune wasn't too difficult to start with.


What year is the truck? Too bad you didn't have the 46rh, so you wont have to mess with piggybacking or a separate TCU. Keep in mind, if the state requires emissions testing, then the MS might present a problem considering there are no emissions controls AFAIK. A GM ECM would work well if EGR, CCP, and other emission equipment is needed.

 

truck is a 95, which luckily enough classifys as an antique in my state no no emissions is necessary! It also has the 46 re (freshly rebuilt). I have an EGR delete.

So I may be asking some dumb questions, but I am totally lost when it comes to electrical/tuning. All I would have to do is purchase the MS system, plug it into my PCM and let it read codes, then upload tunes?

When you refer to a GM ECM are you meaning GM as in General Motors or is that the name of one of heir systems?

 

The MS is stand-alone, it does not cross talk with the PCM, if it is configured as a piggyback system. There is a need for some decent wiring skills as well as a good understanding of how everything works together, especially if you plan on assembling one on your own. MS has a forum as well. That's about the limit of my knowledge since I have never used it before.


Im talking about an actual GM ECM originally installed in a GM car/truck. Ive seen them on various makes and models that were non-GM.

 

95 should have 46RH, the OBDI PCM has no provisions to control the RE.

 

Heyyou, you are right! I dont know why but I always mix up the RE and the RH! not a good trait