Hi Guys, I have recently completed a retrofit of an OBDII VR6 Engine in to a CE2 MK2 (I have done the wiring only in this instance) I have completed MK2 swaps on multiple occasions in the past with no major issues CE1 -> Digifant 3.2 CE1 -> 1.8t AUM/AGU/BAM CE1 -> 2.8 OBD1 CE1 -> 1.9T CE2 -> 2.8 OBD1 And Finally the CE2 -> OBD2 VR6 has probably being the one that has fought me the most, The one I thought that would be the least resistant. The Car runs and starts, the engine runs not so great currently that is probably more to do with the Fact the Intake tract Is not yet complete and there is no exhaust system currently fitted (no 02 sensors etc) One of the last items that is driving me bonkers is the Tachometer is not working... at all I have completed the usual wiring and connected a MSD 8920 between the Tacho Feed and the Cluster Green/Black Wire from Pin 22 on the ECU has been connected to the White Wire (Input) of the MSD The Purple wire from the MSD has been connected directly to the Tacho input for the Cluster T28/10 1. Originally I had it connect inline with the Tacho signal running thru the Fusebox as per factory but to rule out any issues with the Fuse box, I went and connected directly. 2. I have ruled out any line break between the ECU and and G1/12, No Shorts to ground. 3. I have ruled out Cluster Issues with another known Good Cluster 4. I have ruled out the MSD box with another good MSD box. 5. The ECU is seeing RPM on the measuring blocks I am not entirely familiar with the OBD2 VR6 would there be anything that would stop the ECU sending the RPM Signal down the wire? The ECU seems to log the following fault codes 01247 - Evap Charcoal Short to Ground (This is because there isn't one haha) 00515 - Camshaft Position (Hall) Sensor (G40) 30-00 Open or Short to Plus (is this normal?) 00553 - Mass Airflow Sensor (G70) 31-10 Open or Short to Ground - Intermittent (MAF is connected but Intake is not plumbed up. I am frustrated and wondering what the hell have I missed? Any advice / abuse is welcomed
I can’t answer your question other than to ask is the MSD box you refer to a 6 cyl to 4 cyl converter? Everything is interesting as we will be doing this conversion in the autumn.
Hey Phil Thanks for the reply the MSD box is nothing special, as far as Im aware it takes one signal and amplifies it to 12v Box wave The ECU/Engine being 6 Cylinder and Cluster being 4 cylinder there will likely be a over read maybe 1.25x (rough guess) the amount of actual RPM due to the extra pulses We will need to get a S&P Box or similar to be able to change the dipswitches to account for the disparity However despite this the tachometer “should” still be registering some form of life.
think I replied to you on FB, but from memory I read something a long while back that you need a pullup or pulldown resistor sometimes to get the MSD boxes to work on VW ECU. but as mentioned it alone isnt going to work right even if you did this as you also need one which can convert the 6 cylinder ecu singal to 4 cylinder output for your clocks
Hey Jonny, Yes you replied to Adrian, much appreciated, I was not aware the MSDs were not “compatible” with the VR6 Mk3 gear I have used them for others and they have worked. Including his brothers OBD1 VR6 Mk2 Jetta. (It works it just over reads) i guess that is what has thrown me off! Will save the MSD for a 1.8t swap
details are hazy but I think it was a recent change to their board design? I'm sure I saved the details somewhere but I cant find atm
