Link ECU Issue

[Oni]

Hi all

Car
1990 currently running as NA with the miata link ecu MK2 ( i think Juffa might be able to chime in ) with 330cc injectors and WBO2. The car is still running fine but theres a weird issue that i thought someone might have seen before.

With the ribbon cable ( from ecu ) plugged into keypad the car does it normal prestartup and starts
With the ribbon cable ( from ecu ) unplugged and just sitting on my floor plugged into nothing the car does it normal prestartup and starts
With the ribbon cable ( from ecu ) plugged into the comlink serial-usb adaptor but the adaptor not plugged into a computer the car DOESNT do the normal start up process eg not fuelpump and car wont start.
With the ribbon cable ( from ecu ) plugged into the comlink serial-usb adaptor and the adaptor plugged into a computer the start up process doesnt happen but im able to create a map file in DLL so there must be communications from the ecu to the computer. car will not start.

Now this process when i first installed everything worked flawlessly, all i can imagine is that for some reason it doesnt want to prime/check sensors when the ecu is plugged into the serial adaptor. ive tried a few new usb cables but its weird. its almost like the adapros os broken, yet it has connectivity. Security is turned off as proven by the car starting with the keypad unplugged.

Before i start installing all the turbo goodies id like to be sure i know how to read the data logs etc to be extra safe .
Any ideas? at work atm so i cant really do much but i can test out anything tonight.

Thanks in advance
Scott

[93_Clubman]

As you say Juffa might be able to help - also the US forums (miata.net & miataturbo.net) might be worth a search, given the Link seems to be more popular there. GL!

[Juffa]

Hi Oni,

Good to see you are striking some challenges.....wouldn't want it to go too smoothly.

Are you using Digital Log Lab (DLL) software on your laptop? Are you also using RTlink? I suggest that you double checked all of the DLL program settings are right. For instance if you are using RTlink then change the Data Logging/Upload Program to RTLink.EXE. It is listed in the DLL HTML documentation which gets installed with the DLL software. I remember having a weird problem when I received a new work laptop and I had to install DLL on it. I got one of the program settings wrong and had all sorts of weird things going on. While you check that out I will see what I can remember.

Can you also verfiy that the Commlink serial/USB adaptor is being seen by the laptop. There is a piece of software that confirms the port that the adaptor is using. I'll see what I have on that as well.

J.

J.

[Oni]

Thanks for the reply ill try fill you in.

It was working fine a few weeks ago but trying this morning it was being a pain.
Yep im using DLL and using RTlink as the data logging software on the laptop. Ive ran the comfinder software and its seeing it and i was also able to pull the current map file from the ecu to the laptop so its definatly "talking" to the ecu.

When i got home tonight i thought id give it another go, and although it didnt do the fuel pump it started right up, and started to log. this could have been becusae i had just turned the car off then connected the cable to the commlink adapter and fired up the pc. there may have bbeen enough fuel/fuel pressure to allow the car to start without issues.

Its almost like when the adaptor is plugged in it doesnt want to boot correctly, but it will still output to DLL. Ive yet to try starting the car with the ribbon cable plugged into nothing and then once the car is running plug ribbon cable > comlink adapter > pc> run dll and see what happens, i was a bit worried about how hot swapable that cable might be.

So to confirm the computer is able to get information from the ecu and i can upload maps but if i try start the car with the ribbon cable plugged into the serial adaptor it does do the normal fuel pump on thing and will just keep cranking, im guessing theres no fuel at that point. but if i unplug the ribbon cable and either leave it lose or have it plugged into the handset it will do the fuel pump part and fire right up.
almost like having the adaptor plugged in is shorting something and stopping the pre start thigns from happening.

[Juffa]

Thanks for the reply ill try fill you in.

So to confirm the computer is able to get information from the ecu and i can upload maps but if i try start the car with the ribbon cable plugged into the serial adaptor it does do the normal fuel pump on thing and will just keep cranking, im guessing theres no fuel at that point. but if i unplug the ribbon cable and either leave it lose or have it plugged into the handset it will do the fuel pump part and fire right up.
almost like having the adaptor plugged in is shorting something and stopping the pre start thigns from happening.

Scott, do you mean if you start the car with ribbon cable plugged into the serial adaptor it doesn't fuel pump thing? In my experience the Link ECU requires a good earth. In the stuff I sent you there shoould have been a thick yellow wire. I attached this to one of the earth wires on the ECU wiring loom and ran the other end through the firewall to the engine block earth connection near the back of the engine on the passenger side. Also check all the wires that you had to move in the wiring loom, if one them is loose it can cause similar problems.....make sure you disconnect the battery before removing the wiring loom, otherwise you will fry the ignitor (don't ask me how I know).

[Juffa]

Thanks for the reply ill try fill you in.


When i got home tonight i thought id give it another go, and although it didnt do the fuel pump it started right up, and started to log. this could have been becusae i had just turned the car off then connected the cable to the commlink adapter and fired up the pc. there may have bbeen enough fuel/fuel pressure to allow the car to start without issues.

Unless the fuel pump is running the car will not run for more than 3-5 secs. To start the car with the link ECU installed I would turn the ignition key to the 'on' position. You should hear the fuel pump start. About 6-7 seconds later you will hear a click under the dash. That is the Circuit Open Relay (COR). As soon as I heard the click I would turn the key to the next stage and start the car. If I tried to start the car before hearing the click from the COR the engine would stall. You can bypass the COR and have the fuel pump run at all times that the ignition is on. Use a short wire to jumper the FP and earth connector in the diagnostic box under the hood. I had to do that while I worked out that I had an ECU earthing issue.

J.

[Oni]

Scott, do you mean if you start the car with ribbon cable plugged into the serial adaptor it doesn't fuel pump thing?

Yup thats it. ribbon cable plugged into adaptor = no fuel pump with the key in the second position (on?) when it normally would be. but if i unplug it from the adaptor everything works as per usual.

The effect is the same as what happens if you try start the car before you hear the click ofter the 6-7 seconds. This weekend i was going to redo my grounds as per the install directions with the thicker wire so ill give that a shot. Other wise everything has been running great, car is happy and with either the keypad or nothing plugged in starts up faster than it did on the factory ecu . Will update in a few days on what ive changed and if it helped

Hoping to install the intercooler this weekend, ill be a poser with the intercooler connected to nothing but its one less thing ill have to do once i start the real installation.

[Oni]

So after the weekend i made some progress, i was able to redo the ecu grounds with the thicker wide to the place indidcated in the manual, ill also be moving hte WB ground to this location tonight. i tried last night and the car was happy to start with the ribbon cable plugged into the serial adaptor, i was able to take some logs etc . but alas, i tried thismorning and had no luck, same thing as before. With the serial adaptor plugged in it wont do the usual start up process with the fuel pump etc, but with the cable unpugged or plugged into the keypad its fine.

i might try with the cable unplugged putting the car to the on position and letting it do its normal thing, then plug it into the adaprot and see if im able to start/get signal to the pc. i have a feeling that it wont work unless the ribbon cable is plugged in when the key is moved to the on position.

Strange, and ive not been able to find any other threads like this. im hoping its an intermitant fault with the serial adaptor so i might try sorce another with that same square plug bit.

[Juffa]

That is strange Scott. Did I put two ribbon cables in the with all of the other stuff? I know that one of the cables was damaged when I accidently put a screw through it. I replaced the cable, but kept the old one.... I hope I didn't send you the dodgy one, though from memory it stopped working all together, not just at random. I will look in my shed and see if I still have a cable. If I find one I will check to see if it is the damaged one. I will post back here.

J.

[Oni]

I think ive found the solution i do need to test it a little more

The car ecu will do its normal start up if only the ribbon cable is plugged into the serial connector, but not if i have the usb cable in it. Strange, i do need to test it more thought.

So the process is plug ribbon cable into serial adaptor - turn key to on position and wait for the pump / relay to click then plug in the usb cable to the adaptor and the laptop and it works perfectly fine

Ill do some more testing over the next few days fingers crossed its just a different way of plugging things in.
Easter break the turbo gear is getting installed:).

[Juffa]

Easter break the turbo gear is getting installed:).

Whoo Hoo.