Electronic Control FI Motor - This was new to me!

[wrogers55]

This was fun.

My motor is a mass flow, computer controlled timing 418 ci sb, 570HP flywheel motor. I just had it completely apart for a new cam and springs and decided to buy one of those $40 code readers that plugs into the obdI port connector since I had the wiring all over the place.

Man, did I end up with so much more. A huge surprise.

After a lot of reading I hooked it up and among lots of other cool things, here are two capabilities I didn't know the computer had that the little reader can initiate in test mode.

1. Timing. Most folks say with this computer controlled distributor, set the initial timing with something called the Spout unplugged (no computer control) at a mechanical 10 to 14 BTDC. Plug the Spout back into the computer and take what curve the computer gives you and it is supposed to add about 20 degrees to that for a total of 30 to 34. And it's hard to check with a light for whatever reason, seems to bounce around too much for me. BUT, with the engine running and at the code reader running it through diagnostics, the computer will put it full advance for two minutes and it is dead still and easy to see.......at idle speed. Very cool.

2. Part of that same diagnostic is to do an individual cylinder "pressure" test. It's pretty simple, with the engine running the computer drops each fuel injector out in sequence and looks at the rpm drop of the motor, one by one. If it's out of a specific range (one doesn't drop the rpm something like the same amount) you get a code identifying the cylinder number.

Not the whole answer but I had no idea there was that much diagnostic ability in the A9L little Ford computer. Had the Mass-Flo system installed for a couple of years and no issues at all, but this was fun to learn some of the OEM parts capabilities used in the system, like the computer. And these were only two of dozens and dozens of specific type tests and diagnostics.

I guess old dogs can learn new tricks, as long as they are not too hard!

[bobcowan]

Computer controlled EFI is a powerfull tool. It's amazing what you can do with it.

[DonC]

Wayne:
Just out of curiosity, where did you physically plug the OBD diagnostic tool into the A9L? Since it doesn't have any external ports other than the J3 (on the end of the ECU opposite the large multi-plug) and that port is where the Moates J3 chip is plugged in, does your system have something else wired in?
DonC

[olddog]

DonC there is a port or plug that you can connect to, but it only has maybe 3 or 4 connectors in it. My reader only has a couple options. Basically flashes a LED when you tell it to do a test.

Wayne exactly what code reader did you buy (make model) and where did you connect to?

[wrogers55]

Answers: The code reader I bought is an "Equus 3145 Ford Digital Code Reader". Got it on Amazon for $25 and didn't expect much. Turned out to be really nice and comes with a great and simple manual.

My system, which was installed by Bill Littleton (who seems to have disappeared from the board, but was always super helpful) and has the "factory" connector for the code reader is installed along side the A9L in the passenger side well. Super easy plug in. There is also a plastic cover over that test port pig tail that has two holes in it so you can just jump the right connections without thinking about it to get the codes out using the "check engine light" on the dash. Sounded like Morris code to me so I passed on that one and bought the reader that converts the light flashes to an actual number.

I did use the ignition "go to full advance while idling" today and now I understand better how it works. At the end of the "ignition on engine running" code reading process, when the last code is sent or all OK, the computer puts the ignition in full advance mode for 2 minutes. You just put a timing light on it within the 2 minutes and you can set the full advance without all the rpm drama.

I'm starting to really like that little box. But then again, nothing has really gone wrong with it yet......

Pictures are poor but probably tell the story better than I can anyway.