GEMS - General Engine Management Systems Ltd - Forum

Hello, I hope you might be able to help and this is my first Gems post.

I have a Zetec 2l on carbs running an old Minidls Gems ECU. ECU has always run well and I’ve had no reason in the past to make any changes. After having the carbs rebuilt I’ve now decided to take a look at the ignition map to improve the pickup at 2-3K rpm on a light load. I know this is a common issue on a carb car where the pickup is not always smooth. I recently drove a friend’s car with a very similar engine build. This did have a better pickup and he had spent lots of time adjusting the ignition map adding more advance under light load.

So as a first step I tried to download the current map using the cable supplied and programs on an old floppy disk (disp.exe mdlsmod ?). The mod program allows you to edit the map and then runs disp to access the ECU. This is where I have a problem. Disp.exe shows the ECU as offline. I’ve tried different com port settings and am now using an old winXP machine with a physical com port but no connection?

I downloaded the “calibration upload tool” from the website. Using the mindlsv116 gin file, this did connect and prompts for the calibration file to upload. I assume this shows the ECU and cable are fine. This is looking for a “.cal” file while the old DOS program loads a “.DO” file.

At this point I just wanted to download the current ignition map and then use this as a base before trying to make any changes. Do I have the correct program I’ve seen “gemscom” mentioned on the forum?

Thanks in advance for any help and advice.

Hi! Welcome!

Disp is very old and will not run in a DOS window in XP, only in 'true' DOS.

Regardless, as it is version 1.16 is a later version which will be compatible with Gemscom which should run on your XP machine. I'll follow this post with a PM with the files for Gemscom.

I will try to locate some extra info for you but we charge £75 for GEMSCOM as we have to build a setup for customers, as it is no longer readily available. However, where some people think that GEMSCOM is 'free' , comes from the fact that the software is not protected, so if you find someone with a version, you can copy it from them 'for free'.


HTH

Rico

Many thanks for the quick help. I have the PM and will try the exe tonight.

Thanks again for the quick reply.
Well it almost works. Gemscom does connect to the EMS but keeps going offline. Sometimes it’s only online for a few seconds; sometimes it seems to stay connected for a minute or two.

When it is connected I can see the battery voltage, TPS values etc so it seems to be feeding back.
I tried to save the current calibration? The download completes but sometimes gives a checksum error? I tried it a couple of times and it did then save with no displayed errors. I also tried the ‘save EMS to work file?’, then compare EMS to work file. I expected these to be the same but it reported some of the ignition set points to be different?

I have not tried to upload any changes to the EMS as I was worried that the data could get corrupted with these strange errors? All of this was done with the ignition on but the car not started. Is this right?

Any suggestions on the errors I guess this is not right? It seems so close. I followed the program help but is there a manual or user guide to explain the steps to update an ignition curve.

Thank again for the help.

Tried to email you earlier with a copy if the GEMSCOM manual. Please let me know that it has arrived safely.

The issue with the intermittent connection does sound like a bad wiring issue, either a broken cable or bad connection but without putting a multi-meter on the job, it's hard to determine remotely. Anyway, some coms connectors are soldered directly to the board and some mounted on the case and connected to the PCB by three wires. If yours is the latter, this is the wiring that you should have a look at. If the connector (is it a 3-pin binder) check the connections with the PCB. Also, GEMSCOM can be a little unstable when not run if a 'pure' DOS environment.

Do you have the MiniDLS manual..?

Best regards,
RickS

Hello thankyou for the Gemscom manual. A little reading for tonight? If you could send me the mindls manual to go with this that would be great.

Rick I replied to your message and sent the downloaded .do file along with a comparison map I was hoping to get closer to.

I could grab a multimeter and try and check the cable. As its working some of the time I assume the correct pins are being used. The 3 pin plug the serial lead connects to is part of the loom and not taken from a plug on the board. I have a picture of the internals I will try to attach. What connection should I check on the multiplug?

Thanks again for the support.

A copy of the DLS manual is winging it's way to you as I type. On page 11 (Appendix A) there is 'pin out' information on what gets connected to which pin, including Tx, Rx and Ground information. There is also a tidy little schematic describing the loom.

Best regards
RickS

Cheers for the manual. I'm wondering if this is a grounding problem as it's so intermittant and does not seem to follow any pattern. Will take a multimeter home at the weekend and try to make some checks on the cable and pinouts. If I can stop the ECU going off line then I'll try updating the map.

Thanks again for the help.

OK. Let us know how you get on.
BR
RickS

Hello all, problem turns out to be an issue with running Gemscom under windows XP. As a test I made a DOS bootable floppy and ran Gemscom from the floppy. Now no issue with ECU going offline. Also downloads etc seem to be much faster? A couple of 'out of memory' warnings when comparing files but I guess allocating some more memory from DOS will fix that. Thanks for the help and now to editing the map.

OK....
Have taken note of the irregularities running this under XP.
Keep us abreast of how the tuning goes.
BR
RickS