Electronic Control FI Motor - This was new to me!

wrogers55 · #1 (**permalink**) 06-02-2012, 08:42 PM

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!