My dad has a 2002 Mitsubishi Diamante VRX TJ model with a 6g74, long story short, the distributor packed it, wasn't getting any spark so I got it on good word the distributor or computer could be faulty, I got a second hand one and now it starts but it doesnt run right. At idle it will only rev out to 4000rpm and when you drive it the transmission shifts very funny, like its in a limp home mode or something and now the TCL light flashes on the dash.



I decided to get a computer for it as well, the guy I got it from said the one from the car that had the distributor in it had gone but he had another one, I plugged that one in but the car doesn't run on it.



I put the old one back in and got it scanned, when it was scanned they said it only had a code in it about the immobiliser communication. They said they would need to do some tests on it to check it out since it had no faults logged relating to the drive problem and said it could cost a bit and said to try another air flow meter.



So I swapped the computer I got for a air flow meter and tried it and it still made no difference. Only thing I can think is the distributor I got not right for the vehicle, all the numbers on it were the same and it actually did start it. I'm not sure what to check next.

One way round this would be to send the ECU to Steve Knight Racing in Adelaide.
He can unlock an ECU and then disable the immobiliser function.
Otherwise you will have to look at what I believe is the Brown wire circuit from the ECU to the BEM, Body Electrics Module??, and from the BEm to the key sensing coil at the front of the ignition barrel.

You can tell if the immobiliser function is coming in. The engine will crank, there will be sparks, but will not fire. This is because the ECU is not sending a signal to the injectors.
Have a look at the circuit diagrams published in the workshop manual. Manuals are on this site.

The ECU and BEM are electronically paired to each other, a new BEM will require a MITs dealer to reprogramme so it will work with the ECU. Some of them may even sting you for a set of keys as well.

Gerry.

Clearly there is no immob issue here as it runs on the orig ecu and not on the replacement so can rule that out all together

I would look at another dist, if the initial dist was infact what stopped it running, which I actually doubt, you may have been unlucky and been given another faulty one. Have your tried your original dist back in the car again?

In so far as ecu goes, you will need to unlock it to make it work or get the map off your original box and put it into your new box. I can do this as can Steve but little benefit to be honest.

Also could be the CAS but then the car generally would not run at all. I would go back to your starting point with all orig parts and then one by one try parts but if no improvement put the old bit back in. If I had the car here, just listening to to it will usually give me a good indication of the issue

Clearly there is no immob issue here as it runs on the orig ecu and not on the replacement so can rule that out all together

I would look at another dist, if the initial dist was infact what stopped it running, which I actually doubt, you may have been unlucky and been given another faulty one. Have your tried your original dist back in the car again?

In so far as ecu goes, you will need to unlock it to make it work or get the map off your original box and put it into your new box. I can do this as can Steve but little benefit to be honest.

Also could be the CAS but then the car generally would not run at all. I would go back to your starting point with all orig parts and then one by one try parts but if no improvement put the old bit back in. If I had the car here, just listening to to it will usually give me a good indication of the issue

Yeah you are right about the immobilizer issue, sorry I should have made it clearer. I did try putting the original distributor back in, car wouldn't start again like it was originally doing so I figured the dissy I gotmust have been alright, will try get another one though.

Are the ECU's coded to the particular vehicle or something is that why the immobilizer won't work? I suppose that makes sense since it is a security thing. CAS = Crank angle sensor? if that was faulty wouldnt it make a code come up. What oocured today to me as weird was the TCL light was flashing not the engine light, possibly a transmission problem?? I will try find another distributor though and go from there.

Cheers

Are the ECU's coded to the particular vehicle or something is that why the immobilizer won't work? I suppose that makes sense since it is a security thing. CAS = Crank angle sensor? if that was faulty wouldnt it make a code come up. What oocured today to me as weird was the TCL light was flashing not the engine light, possibly a transmission problem?? I will try find another distributor though and go from there.

Cheers[/QUOTE]

The ECU's need to be matched to the type of gearbox & wiring fitted to the vehicle ie: 4 / 5 speed auto or manual. If the vehicle has traction control then the ECU needs to the relevant circuitry built into it. If you look at the ECU casing it should have a sticker on the side that says something like: ECU TJ8D42 MR988207 Body number, sequence number and date. The ECU also has a sticker on the top of it which relates to the type of transmission fitted & whether or not it has TCL ie: MMAL DOM 4AT - SPT W/O TCL ie:-4 SPEED AUTO TRANSMISSION-SPORTS WITHOUT TRACTION CONTROL. I have used a non TCL ECU with matching BEM & keys out of a TL/TW to start & run a TJ2 executive but when taken for a road road test the engine went into limp mode as the TL/TW's take their speedo reading from the ABS system and not the gearbox. I have also used the same TL/TW ECU to start & run at idle a KH Verada with TCL and found the TCL light flashed continuously.

Cheers

Wow, I just looked at the main Mitsubishi part number the MR######## number which was exactly the same, haven't looked at the other numbers.

Ok I ended up taking it to a garage to get it fixed, they said the coil inside the distributor was faulty so they replaced that and it idlesand everything fine now, they said the TCL Light flashing is another problem possibly caused by when I was working on the distributorand they would need to check it out, anyone have any ideas on what it could be? they said they had a look and couldn't see anything disconnected under the dash or around the distributor.