FAST EFI "Com Error"

[33FordFan]

Anyone ever experienced this "com error" with the FAST EFI set up? Thought I was going to get the first start knocked out this weekend but ran into some troubles, one of them being the com error on the hand held data logger.

I'm using the Ron Francis Harness if that matters. The FAST EFI is wired directly to the battery (pos and neg terminals) and have tried the switched power wire connected to both the EFI crank and coil wires with out luck. Might have to finally break down and ask my ASME buddy to lend a hand but I was really hoping to pull off this project solo.

[SIZE-O]

Does the engine try to start but just doesn't catch.? Have you tried the following;

1. Fuel, do you have pressure (43psi)and flow at the fuel rails?
2. Spark, have you pulled a plug, hold it up to the block and crank the motor to see if you are getting spark.
3. Pull the distributor cap and check if the rotor rotates while cranking the engine. Is the rotor loose in anyway.
4. Assuming you have a MSD box. Are you getting a tach singal at the comuter. Won't start without it.

Perry

[lbperry]

I'm sure that you'll get more authoritative answers but a COM error usually means you have a bad connection between two devices. If the data logger can't see the EFI unit or vice versa that would be a COM error. I'd check my cable connections to start with.
Good Luck,

[alfie]

Hi Fordfan,
Check page 14 of the instructions as it discusses it there. It basically says check the cable connections for the handheld and make sure the ECM is powered. I am assuming they mean the 12v battery power and the 12v switched power from the ignition switch. If it did not have the switched power you probably wouldn't have communication to the handheld.
As for the no crank power or power to the coil that should have nothing to do with the ECM other than they are all powered from the ignition switch.
I think I would start by making sure your ignition switch (and or relay) has power and then verify that the ECM is seeing a switched 12v source as well as the bat power. And of course grounds, always triple check the grounds.

Hope this helps
Steve

[33FordFan]

I'm definately going to double check my grounds. Might just run temporary extended neg wiring directly to the battery so I can rule out a bad ground. The starter doesn't atttempt to crank and I've got no spark. I have 40ish lbs of fuel pressure. I realized as I tossed and turned last night that my solenoid is mounted on the firewall and not the frame as the installation guide shows. Could that be the culprit? That's the first thing I plan to fix (either by moving the solenoid to the frame or running a ground wire from solenoid where it is now on the firewall to the frame). While I'm at it, I'm going to start over and trace every wire and see if I can get another FAST handheld pigtail. I got into a rush to try and get my first start and obviously missed something important. Appreciate the feed back. I'll post up results of further troubleshooting and eventual fix in case anyone else might ever have similar issues.

[33FordFan]

Okay so I have spark, and fuel but the motor still won't start...

Starter wasn't previously working...Grounding the starter solenoid sorted that out.

Car would then turn over but I didn't have spark...Reconnecting the neg wire from the dizzy to the neg post of the coil fixed that.

I'm wondering if this "com error" on the FAST hand held has anything to do with it. Also, there appears to be a small LED light on the actual FAST ECM. It's not lighting up so that may give some indication of what's going on to someone more informed than myself. I thought that perhaps the ECM needed to be grounded so I grounded it to the same spot that I did the starter solenoid but still no-go. Gonna have a mechanic buddy come over on Sunday and help me try to sort it all out. Till then, any advice recommendations are welcome.

One question my buddy had which I couldn't answer.

Of the EFI coil (blue) and crank (orange) wires, where does the blue wire go to? It appears to come off the start post of the starter solenoid same as the clutch saftey switch wire. I currently don't have it hooked up to anything. The orange wire, hot when the starter switch is keyed "on" is connected to the switched wire on the FAST ECM. The pos and neg for the FAST ECM are wired directly to the battery.

[33FordFan]

Just a follow up note to my previous posts...

I sent the ECM back to FAST after discussing with them over the phone the symptoms I was experiencing. They repaired the ECM under warranty. Not sure exactly what was wrong but the ECM was not seeing power. Once I plugged the ECM into the wiring harness she fired right up. So the lesson learned here was if the ECM doesn't light up when you attempt to start the motor, you have major trouble. So now I'll clean up my wiring and be ready for go-kart before too long.

Side note... Hearing that 408 rev is music to my ears.

[lbperry]

Good Deal. Glad to hear that you got it worked out.
Good Luck