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D2 Cranks but will not start

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  #11  
Old 05-13-2021, 06:33 PM
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Originally Posted by RoverMasterTech
See if the OBD tester reads RPM while cranking. If it doesn't, it's something with the crank sensor/ecu/harness for sure. If you have RPM when cranking, check the ground pulse to one of the coils and power to the coil.
Maybe try this
 
  #12  
Old 05-13-2021, 08:46 PM
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Default D2 Cranks but will not start

Originally Posted by The Deputy
Sounds like you're going to have to dig into the coil pack harness/plugs, check for voltage and pulse signal from ECM.
After reading the suggestions from RoverMasterTech I bought a Logic tester today so that I could do this at the weekend. Question is, do I have to do this at the coil packs (not the easiest to get to) or can I do it the engine harness to main harness connector at the rear RH side of the engine bay.
 
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Old 05-14-2021, 01:06 AM
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Originally Posted by Rutmaster
After reading the suggestions from RoverMasterTech I bought a Logic tester today so that I could do this at the weekend. Question is, do I have to do this at the coil packs (not the easiest to get to) or can I do it the engine harness to main harness connector at the rear RH side of the engine bay.
Me, l'd start at the ECM, back probe terminals in wiring diagram supplied. Truthful, for both coil packs to be not supplying spark, and fuse #14 and relay are good...l'd think you've have water damage or something to your ECM. It would be very strange, to have coil wires on both coils rub through somewhere or be broken.



 
  #14  
Old 05-14-2021, 08:15 AM
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When checking a crank/nostart ALWAYS check the RPM with a scan tool. It's the 1st thing you do. If the ECU is telling you no rpm, you have an input problem. If it shows RPM you have an output side problem.

"Originally Posted by RoverMasterTech View Post
See if the OBD tester reads RPM while cranking. If it doesn't, it's something with the crank sensor/ecu/harness for sure. If you have RPM when cranking, check the ground pulse to one of the coils and power to the coil."
 
  #15  
Old 05-27-2021, 08:45 PM
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Smile D2 Cranks but will not start

After considerable hours of troubleshooting and swapping of parts from the other D 2 the engine starts.

Update on how I got there (Note that I do not have access to a OBD2 scanner with live stream or RPM readout - I am open to suggestions on which is the best one to buy Smile)

With the use of the logic tester (OTC 3630) I checked for the voltage and pulses as per the schematic from RoverMasterTech - Pulses were present at the ECM on pins 2,6,7 & 8. Ground on pin 5
I then checked for voltage at the engine harness to main harness plug (located at the rear RH side of engine compartment) - Voltage on pins 4 & 5
Unbolted the coil packs and pulled upwards to gain access to the connectors to check continuity of cables from ECM pins 32, 45 & 46 to coil packs - All good
Plugged connectors into another set of coil packs - engine cranks - no spark at plugs
Unplugged the ECM and BCU and fitted the ECM and BCU from the other D2 - engine cranks - no spark at plugs

After reading several threads reporting issues with the fuse boxes:
Changed out the engine bay fuse box - cranks but still no spark
Changed out the interior fuse box in the drivers footwell - cranks and started

I then rechecked everything that I had done to see if there were any changes with the Ignition off, Ignition on , and cranking - All readings, voltages, grounds, pulses etc were the same.

I opened the fuse box for inspection but could not see what could have caused the issue.

My sincere thanks to all that provided guidance and I hope that my write up will be helpful to others who may encounter this issue.
 
  #16  
Old 08-27-2021, 09:52 AM
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Originally Posted by The Deputy
Check fuse #14 in drivers compartment fuse box (coil pack fuse) for continuity and power with key on and relay R4 (ignition relay, right lower). Bought a Dll, $500, wouldn't start, had fuel/cranked strong...but no spark. Checked the coil pack fuse #14, good, went to swap relay and as soon as l touched it...it felt out in my hand. Pushed it back in and she fired right up.

l know you said you pulled fuse boxes looking for short to ground or loose connections...but l didn't read where you checked fuses, fuseable links or relays.

Good luck.
I have been having the same problems (no spark). I saw your post and pulled fuse #14. It looked fine, but after I put it back in, the engine started right up. Perhaps a loose connection in the fuse box?
 
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  #17  
Old 08-27-2021, 08:49 PM
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Originally Posted by Jjcopen
I have been having the same problems (no spark). I saw your post and pulled fuse #14. It looked fine, but after I put it back in, the engine started right up. Perhaps a loose connection in the fuse box?
Thanks JJCOPEN, I'll look into this on Monday when I'll be where my Disco is parked. In any case, I have an appointment for Sep 9th to bring it to a very well recommended shop in Pompano. I'll keep you guys posted... ;-]#

 
  #18  
Old 08-28-2021, 03:38 AM
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Originally Posted by Rutmaster
After considerable hours of troubleshooting and swapping of parts from the other D 2 the engine starts.

Update on how I got there (Note that I do not have access to a OBD2 scanner with live stream or RPM readout - I am open to suggestions on which is the best one to buy Smile)

With the use of the logic tester (OTC 3630) I checked for the voltage and pulses as per the schematic from RoverMasterTech - Pulses were present at the ECM on pins 2,6,7 & 8. Ground on pin 5
I then checked for voltage at the engine harness to main harness plug (located at the rear RH side of engine compartment) - Voltage on pins 4 & 5
Unbolted the coil packs and pulled upwards to gain access to the connectors to check continuity of cables from ECM pins 32, 45 & 46 to coil packs - All good
Plugged connectors into another set of coil packs - engine cranks - no spark at plugs
Unplugged the ECM and BCU and fitted the ECM and BCU from the other D2 - engine cranks - no spark at plugs

After reading several threads reporting issues with the fuse boxes:
Changed out the engine bay fuse box - cranks but still no spark
Changed out the interior fuse box in the drivers footwell - cranks and started

I then rechecked everything that I had done to see if there were any changes with the Ignition off, Ignition on , and cranking - All readings, voltages, grounds, pulses etc were the same.

I opened the fuse box for inspection but could not see what could have caused the issue.

My sincere thanks to all that provided guidance and I hope that my write up will be helpful to others who may encounter this issue.
Probably fuse #14 had corrosion or loose connection, or ignition relay could cause same issue. Checking for voltage is a funny thing, it can be there with tons of resistance, volt meter will show 12v and test light will light...but...if corrosion or resistance is to much/great and coil pack is not receiving enough amperage...then...Houston we have a problem. Amerage is what makes things work on your vehicle, voltage is basically just a reference. And most folks get wrapped up about "seeing 12 volts at their meter or not"...when in truth...you should be more wrapped up with what type of amerage you're getting.

So, with that being said...when you checked everything, before and after, and found voltage readings the same...this doesn't surprise me...since it was most likely a amperage (corrosion/resistance) issue at fuse box.

If l had a dollar for everytime a tech came up to me and said..."I got power there"...l'd be rich. Or if l had a dollar for everytime a corroded fuse was the culprit...same results...rich. A 10 amp fuse carries 10 amps...but if the 10 amp fuse is corroded/poor connection and only 2 amps are crossing its blades...components don't work. Like, let's say coil packs for instanance.

Glad you got her running.
 
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