Link ECU Injector firing problem
 

Hi Guys,

Greetings from Singapore. I currently have a FM Link ECU Mk2, running 550cc RC Engineering injectors.

I've recently been having problems with my Injectors. For some reason, the sequential injector modification that I made to the car stopped working (4th cylinder injector stopped firing, there was no current in the wires. I checked the wires I had run for the sequential mod from the ECU to the injectors and they were fine.) and the 4th cylinder basically blew. After re-building my engine, I re-wired the injector harness and then ran batch firing for awhile (4 weeks) with no problems.

However, recently, I have been having trouble with starting the car, which was traced to an injector problem. Basically, the 4 injectors are firing almost non-stop and the cylinders are flooded with fuel and the car can't start properly. I'm in the midst of checking the wires, but I'm worried that the ECU might be faulty now. Has anyone had any experience with Link ECUs failing like this?

Also, the handheld controller boots up fine, but sometimes when I scroll to different screens, and then I press the edit or adjust keys, the screen shows gibberish and continues showing it. Most times, the gibberish goes away and the display goes back to normal if I press the upper left corner of the handheld controller. Is this just a keypad issue or is there something more significant that I should worry about?

Lastly, if all else fails, would anybody happen to have second hand Link ECUs lying around that I might be able to purchase directly?

Thanks
Tim

The keypad gibberish is usually a sign of a bad keypad ribbon cable. Swap the cable out and then test to see if the injector issue is cleared up. If not:

Swap in a stock harness for your mod sequential harness and change the Link appropriately. That will at least indicate that the injector circuits are working, or not.

Link ecus were popping up for cheap, not so much anymore.

thanks so much for the reply.......
here's what i got from Brandon Fitch over at FM!!! (they ROCK!!!!)

Hi Tim,

Wiring could definitely be the culprit there. However, if you're confident that the wiring is 100% correct, I'd look at the injector. If they've been in the car for a long time (especially if the car sat for a long time), they're probably gummed up. There are companies that do official cleaning, you should be able to find one local to you.

As for the handheld controller issue, that sounds like a bad solder joint. I would try (gently!) flexing the cable where it plugs into the controller. If you can get the gibberish to come and go, that's where your problem is. Look very closely (you may need a magnifying glass) for any kind of lines or cracks in the solder joints. If you find some, re-melt the solder, add a little more solder, then re-assembly. These cranks could be at the ECU or the controller, although they're more likely to be at the controller.

I traced the problem to the solders at the legs of the wiring loom at the ECU. Re-melted the solder and added on some extra globs of Solder to the Circuit board and everything seems fine for now!!!!