NO SPARK ON ENGINE CRANK. - 99 VW CABIO MK3 NOT MK3.5

  • Tiny
  • CajunSpike
  • 1999 Volkswagen Cabriolet
  • 90,255 miles

New: coil, cap, rotor, coil wire, plug wires, plugs, crank position sensor, battery, electrical end of key switch.
Swapped in substitute ecu, same part number, different suffix. My ecu ends with Q. Swap ends with D. Otherwise same part number.
Verified continuity of crank position sensor center wire back to ecu harness. Verified continuity of distributor sensor center wire back to ecu. Did not check +- on either connector.
Nothing I've changed has made coil spark. Alarm did go off when fresh battery installed. Reset using key in driver door unlock.
Starter cranks normally. Just nothing works to allow the system to spark. This is making me nuts. Any help appreciated.
testing spark by grounding coil output wire to block.
check engine light on with key on.
no codes showing with obd reader.

Do you
have the same problem?
Yes
No
Sunday, March 18th, 2012 AT 12:44 AM

18 Replies

  • Tiny
  • CajunSpike
  • Member

Pic added.

Was this
answer
helpful?
Yes
No
Sunday, March 18th, 2012 AT 12:46 AM
  • Tiny
  • CajunSpike
  • Member

Also removed/cleaned/reconnected valve cover ground and block ground wires.

Was this
answer
helpful?
Yes
No
Sunday, March 18th, 2012 AT 12:53 AM
  • Tiny
  • rasmataz
  • Member

Have you checked the camshaft sensor on the distributor

Was this
answer
helpful?
Yes
No
Sunday, March 18th, 2012 AT 1:16 AM
  • Tiny
  • CajunSpike
  • Member

I tested continuity from the camshaft sensor center wire up to the ecu, thru the harness. If there is a specific way to test the sensor, please let me know.

Was this
answer
helpful?
Yes
No
Sunday, March 18th, 2012 AT 1:26 AM
  • Tiny
  • rasmataz
  • Member

Check the CMH wiring for short and open circuit back to the computer if okay-have the computer tested-also go this link: http://www.youtube.com/watch?v=itMXO56z1tw

Was this
answer
helpful?
Yes
No
Sunday, March 18th, 2012 AT 2:07 AM
  • Tiny
  • CajunSpike
  • Member

Very good link. I found a similar car in the junkyard. I'll go pull the distributor if it exists, and use it to trouble shoot this issue. 100% thanks for your interest and help. This isn't finished until the car starts.

Was this
answer
helpful?
Yes
No
Sunday, March 18th, 2012 AT 2:42 AM
  • Tiny
  • exovcds
  • Member

Cam/distributor signal is hot needed on this engine for it to run... the crank signal is the main
input. Crank sensor output should be close to 2V AC or more while cranking.

http://www.picoauto.com/waveforms/images/zoom/crankshaft_sensor_inductive_cranking.png

Thomas

Was this
answer
helpful?
Yes
No
Sunday, March 18th, 2012 AT 2:48 AM
  • Tiny
  • CajunSpike
  • Member

Then that brings up the question of how to test the crank sensor. I just spent 5 hours installing a brand new one.

Was this
answer
helpful?
Yes
No
Sunday, March 18th, 2012 AT 3:02 AM
  • Tiny
  • CajunSpike
  • Member

I've got a dvom. But thats about it as far as test equipment goes.

Was this
answer
helpful?
Yes
No
Sunday, March 18th, 2012 AT 3:06 AM
  • Tiny
  • CajunSpike
  • Member

Again, I confirmed continuity from the center crank position wire to the ecu wiring harness. Not sure what voltage or ground is on wires 1/3. I could test that too if somebody knows which is which.

Was this
answer
helpful?
Yes
No
Sunday, March 18th, 2012 AT 3:10 AM

Please login or register to post a reply.

Similar Questions