1Z engine, does rev counter work off alternator or crank - Troubleshooting - VWDiesel.net The IDI, TDI, and mTDI source.

• 1Z engine, does rev counter work off alternator or crank by dub fatha on 03 Feb, 2008 11:16
• hi there,
  
  am trying to wire up my rev counter in my mk2 golf, which is fitted with a mk3 1z tdi engine,
  
  please can someone let me know if the rev counter works off the alternaor, or the crank sensor,
  
  thanks
• #1 by Vincent Waldon on 03 Feb, 2008 12:24
• Kinda neither... the TDI cluster gets the rev signal from the engine's computer (ECU).  
  
  The computer likely gets it from the crank, but I don't know if it the crank signal is available separately.
  
  Either way, it's not going to drive an MK2 cluster directly since the cluster is expecting a W signal... a very different waveform and frequency from the crank or ECU.
  
  Looking up Dakota Digital on the web might be helpful... they make a bunch of tach signal converters and may have one that will work.
• #2 by dub fatha on 04 Feb, 2008 04:59
• Quote from: "Vincent Waldon"

  Kinda neither... the TDI cluster gets the rev signal from the engine's computer (ECU).  
  
  The computer likely gets it from the crank, but I don't know if it the crank signal is available separately.
  
  Either way, it's not going to drive an MK2 cluster directly since the cluster is expecting a W signal... a very different waveform and frequency from the crank or ECU.
  
  Looking up Dakota Digital on the web might be helpful... they make a bunch of tach signal converters and may have one that will work.

  
  
  hi there,
  this is where it gets tricky,  my car is fitted with a mk4 dash board and cluster,
  
  sorry, i should of mentioned this before, but just thought id find out where the signal comes from first
• #3 by MikkiJayne on 04 Feb, 2008 09:36
• You have a mk2 Golf with a mk3 engine and mk4 dash?  :?  That must have been fun to wire up!  :shock:
  
  Assuming you're using the mk2 or mk3 CE2 fusebox then you will find the tach signal coming in from the ECU on plug G1 pin 12 - black/green wire, and it comes out again on the cluster harness on plug U1 pin 6.
  
  Good luck! Mikki x
• #4 by MikkiJayne on 04 Feb, 2008 14:24
• Ok I just read your other thread in the TDI section where you say you have an AAZ pump on your 1Z, so no electronics. That means no ecu to provide a tach signal  
  
  The only tach signal you'll get from that engine is off the alternator, but that signal won't drive the mk4 cluster so you're a bit stuck I'm afraid!
• #5 by dub fatha on 05 Feb, 2008 05:00
• Quote from: "MikkiJayne"

  Ok I just read your other thread in the TDI section where you say you have an AAZ pump on your 1Z, so no electronics. That means no ecu to provide a tach signal  
  
  The only tach signal you'll get from that engine is off the alternator, but that signal won't drive the mk4 cluster so you're a bit stuck I'm afraid!

  
  
  oh s*~t, i guess i am a bit stuck, it looks like ill have to call in an electritian and let him pull his hair out.
  
  or i could fit the correct diesel pump on the 1Z and source a 1Z ecu from somewhere
  
  i appreciate your help though, i have to say that this is the most helpful forum that i have been on.
  
  thanks to everyone for all there help
• #6 by MikkiJayne on 05 Feb, 2008 10:58
• There are loads of 1Z mk3s being broken on ebay so you should be able to source the electronics reasonably easily. Remember to get the key, the immobiliser transponder and ecu all from the same car if you go this way though otherwise you will be in even more of a pickle than you are now! You can often pick up an entire car / conversion for £200  :wink:
  
  That said, Dakota Digital is good advice and worth a look. They may well have something that can drive a later cluster with an early (or W) rpm signal.
• #7 by BigVWman on 07 Feb, 2008 16:36
• Wow i envy you guys the cost on these on this side of the pond is through the roof!
• #8 by dub fatha on 18 Feb, 2008 04:15
• Quote from: "MikkiJayne"

  There are loads of 1Z mk3s being broken on ebay so you should be able to source the electronics reasonably easily. Remember to get the key, the immobiliser transponder and ecu all from the same car if you go this way though otherwise you will be in even more of a pickle than you are now! You can often pick up an entire car / conversion for £200  :wink:
  
  That said, Dakota Digital is good advice and worth a look. They may well have something that can drive a later cluster with an early (or W) rpm signal.

  
  
  thankyou  very much for the advice matey.
  will look into this.
• #9 by dub fatha on 18 Feb, 2008 04:16
• Quote from: "BigVWman"

  Wow i envy you guys the cost on these on this side of the pond is through the roof!

  
  
  hi there,
  do you mean the cost of a engine etc?
  
  i always thought parts were cheaper on the other side of the river
• #10 by MikkiJayne on 18 Feb, 2008 04:24
• Most things are, but TDIs are rarer in the US than they are here so command a higher price.
  
  The larger numbers we got, the age of the cars, plus the combination of salted roads and the mk3's abysmal build qality means there are loads of them being broken, hence they get cheaper.