Introduction and Situation/Questions - Long

[lbperry]

I am in the middle of a build that will have a Ford 351W with PowerJection III intake, Mallory Max-Fire distributor, and Ford 4R70W 4 spd auto.
The 351W is currently on a test stand running a carb, and a no name disributor. From my studying of the PJIII specs, I will have a pretty significant set of laptop tuning capability with it. The Mallory Max-Fire has quite a bit of tuning capability, but it's not real time. The 4R70W will have it's own standalone controller. From my reading of the "Performance Fuel Injection Systems" book, the main area that I would need to address with a MegaSquirt system is spark control. And eventually integrate the fuel and transmission control into the main ECU.
I guess I've got two questions: 1) Is there anyone using a MegaSquirt system with a PowerJection III or similar system? 2)Is my overall plan reasonable? I know that there likely more preferable ways from an MS perspective, but I think my plan will allow me to get the car set up and running and then integrating the MS step by step, leaving a fallback path if I run into problems understanding or implementing the MS ECU.
Part of my reason for asking these quesions is because I plan to go to the MS demo at Road Atlanta at the end of April and I'm tring to figure out what areas to look at and what questions to ask.
Sorry for the long post and thanks for your time,
Lawence

[Matt Cramer]

I am in the middle of a build that will have a Ford 351W with PowerJection III intake, Mallory Max-Fire distributor, and Ford 4R70W 4 spd auto.
The 351W is currently on a test stand running a carb, and a no name disributor. From my studying of the PJIII specs, I will have a pretty significant set of laptop tuning capability with it. The Mallory Max-Fire has quite a bit of tuning capability, but it's not real time. The 4R70W will have it's own standalone controller. From my reading of the "Performance Fuel Injection Systems" book, the main area that I would need to address with a MegaSquirt system is spark control. And eventually integrate the fuel and transmission control into the main ECU.
I guess I've got two questions: 1) Is there anyone using a MegaSquirt system with a PowerJection III or similar system?

Probably the most reasonable approach here would be to have the MS control the fuel and ignition, using the PowerJection III fuel delivery hardware. Which can be treated a lot like a GM TBI. There's quite a few TBI installs out there. The one potential pitfall I could see is if you're trying to use the returnless fuel pump setup; MS currently does not control a variable speed fuel pump.

2)Is my overall plan reasonable? I know that there likely more preferable ways from an MS perspective, but I think my plan will allow me to get the car set up and running and then integrating the MS step by step, leaving a fallback path if I run into problems understanding or implementing the MS ECU.
Part of my reason for asking these quesions is because I plan to go to the MS demo at Road Atlanta at the end of April and I'm tring to figure out what areas to look at and what questions to ask.
Sorry for the long post and thanks for your time,
Lawence

If you want the MS controlling ignition only, it certainly can do that, just leave the fuel outputs disconnected.

[lbperry]

Thanks for the reply, Matt.
I've got the fuel supply line installed already but I'm going to add a return line. The PJIII "Fuel On Demand" is an option that I'm going to pass on, at least for right now, to try to hold the cost down a little.
If I initially use the PJIII for fuel management and the MS for ignition, do you think that they'll play well together? This brings up another question: How do you have a sensor output feeding two different ECMs? For instance, both the fuel management and ignition management would need the Throttle Position Sensor signal, wouldn't they? Any possible problems in this type situation?
I appreciate you input,
Lawrence

[Matt Cramer]

This article is written about stock ECUs but should also cover situations where you are using two aftermarket ECUs.

http://www.DIYAutoTune.com/tech_article ... rallel.htm

[lbperry]

Thanks for the link, Matt. Good Info. I can see I've got a lot of digging to do on the MS sites to begin coming up to speed,
I appreciate the help,
Lawrence