Hi there,
I purchased a 2nd hand PnP VEMS v3.3 and have installed it on my Mk1 VW Golf 2.0 ABF 16v Turbo. The former owner has written a lot of info about the assembly here: http://www.vems.hu/wiki/index.php?page=MembersPage%2FBasilDaham%2FCordobaSX so this should fill most of you in. The car runs wastespark Bosch VW coil with the factory ignitors removed.
As you'll see in the link above, it uses a multitooth 60-2 trigger wheel, which is standard on this engine and located inside the engine on the crankshaft.
When we first installed the computer, the car ran ok, but with a weak spark. After a few starts, the crank signal started to become intermittent: it would appear and then disappear and the car would run and then fail to run without the signal. Eventually, the RPM signal disappeared entirely and "trigger errors" showed up on Megatune. After checking all the grounds (all fine) and everything else, we decided it must be a hardware problem, so sent the ECU back to Hungary where said it showed signs of damage and replaced the board.
To cut a long story short, I now have the ECU back and at first had no crank signal. I decided to pull the harness out of the car and redo all of the grounds to make entirely sure they were ok. After doing this and replacing the crank angle sensor (just to make extra sure) the RPM signal returned. However, the ECU had come back with the 1.0.73 firmware installed and this resulted in no spark. Not being entirely sure how to fix it with all the config. stuff (I'm not used to ECUs that are so DIY), I reloaded the 1.0.53 which the VEMS was previously running. I rebooted the ECU and then the car almost started.
Since this point, the RPM signal has become intermittent again:
- It jumps to 250rpm under cranking and back to 0rpm all the time: signal, no signal, signal, no signal. Sometimes cranking, it'll only register a signal once, the rest of the time nothing shows up on the RPM gauge and the trigger errors symbol appears again on the Megatune.
I have a new mainboard, new crank sensor, perfect grounds and a car that was running fine?!?!
I've now reloaded the 1.0.73Final, but the RPM reading is still intermittent...sometimes there, sometimes not...
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TRIGGER SETTINGS/INFO:
Edge: Rising
Type: Multitooth
Filtering: Disabled
Advanced filtering: Disabled
Special N-1: Disabled
Fiat Stilo: Disabled
TDC after trigger: 60
Number of teeth on wheel: 58
Trigger tooth: 3
Next trigger tooth: 30
Crank min period: 3744 usec
Angular width of tooth: 2
Tooth relation Normal: 122 (irrelevant with multitooth advanced filter disabled)
Tooth relation Missing: 181 (irrelevant with multitooth advanced filter disabled)
Angular width of missing teeth: 6
Engine phase: 240
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- I've checked the voltage coming out of the sensor whilst turning the engine over by hand - it seems perfect:
3.5V, pulled consistently down to 0.05V at each tooth.