I Challenge Anyone to Solve this Discovery No Spark Issue!

[mark D]

Did you make sure the ground was on the CPS side that bolts to the bell housing? Not that it wouild matter really. Just trying to eliminate all issues.

I have heard that sometimes even new CPS fail. Wipe the oil off and take it back to the parts store and get another one. Have you made a request to Disco Mike?? He used to be a LR service manager.
I would replace the CPS first then ask the forum again if you can't detect the voltage. I assume you have checked it on the battery terminals to see if it meter works???

I am at a loss except to say replace the CPS even if its new.

 

[snydesh]

Ok I did a little research and I did not test the crank sensor properly. I didn't realize it is AC not DC. I retested with AC and it read 1.08 to 1.24 so it is working. Now what?

 

[mark D]

Ok sorry for he AC DC misinformation. 1.24 sounds a little low, mine was about 3.4V but if hte signal was consistent then you are getting an accurate pulse.

Lets assume that the CPS is working because the ECM does not need much voltage to time the engine, and lets remember its a computer so high voltage isn't its friend.

Now that you know you have a constant signal its time to find a British shop and ask if they have a Test Book for your rig. Their are a couple of different types as well as a hand held unit.

1) Make sure you tell them everything you have done so far and let them know the CPS is working.
2) Ask if they want the old ECM reinstalled or just leave the new set up in place.
3) button up all the loose ends you need to so the engine and everything is as it should be so you don't give them anything else to fix.
4) drag your rig done and have them hook up the ECM. Make sure they print out a report of all the problems with your rig, so you can fix them later. Don't take a hand written one they can print out a report.

You should be able to drive your rig home if the ECM reboots and the engine starts provided you don't have any other big issues. Mine cost $175.00 to reprogram my old ECM. They said it was easer because the old ECM was previously programed to my vehicle. I don't know if thats true but I didn't care because my DIsco started and ran.

Hope this helped I went through the same issues and jumped through more hoops then we have on this thread.

Good luck please be sure to update this thread with the results after you get back from the mechanics shop so others can benefit from our conversations.

Thanks
mark D

 

[snydesh]

I changed spark plugs and got it to fire up. It ran terrible like before back firing and hesitant on the throttle. Shut it off and it won't crank again. It smoked terribly as well like it wasn't burning all the gas. You still think it is computor?

 

[mark D]

Ohm out your cam shaft positioning sensor and see if the wires are good. I went back and read the beginning thread and your problem started and stopped and restarted when you messed with the cam shaft positioning sensor.

1) are the wires insulated?
2) is the plug broken or wires not fitting correctly in the plug. Jump the plug with a wire and check it with the ohm meter. Wouldn't hurt to carefully take the plug apart and check the connections as well. They do disassemble just be careful the plug slips apart with a pin or neddle.
3) Did your cam positioning sensor fail???? It doesn't work like your CPS it just closes the circuit when the magnet rotates around on the cam grear. The ECM sends a pulse and it returns when the magnet passes by and closes the circuit. The pulse goes back to the ECM which senses the electrical current. Simple

check the plug carefully. I have contacted Disco Mike to help you further he is a retired LR service manager.

Remember you LR is designed to go into limp home mode if one of you components fail so it will run like crap if it senses the code is serious.


mark D

 

[snydesh]

Everything checked good. I am going to order one from a junk yard and try it.

 

[Disco Mike]

Engine will start and run, even when unplugged, it just won't be at the correct engine timing.

 

[snydesh]

Finally ordered sensor today. I will report on findings.

 

[snydesh]

Ok I installed the Cam Sensor and it fired up but it idles great with no miss. I took it for a ride and quickly realized it cuts out going up a hill or trying to accelerate. When I got back home I realized I had left the fuel pressure sensor plug unplugged. (A guy on another forum told me to unplug it and see if it would run, he had his short out causing problems) I plugged it back in while it was idling and it shut of the motor. I cranked it back but it would not idle and ran bad. I unplugged it and slowly increased the throttle and when it gets over 2.5K rpm it will fall back to 2K rpm and then go back up, and fall again. I am going to check fuel pressure and see what is going on. Thanks for the help!!! Any input on the new issue?

 

[snydesh]

For anyone else: I finally found a Rave I could download.

https://www.cubbyusercontent.com/pl...5711943a885e54ed37cc7a7ed#LR3 workshop manual