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There were issues with the CPS, Temp Sensor and MAF Sensor wiring.
The mechanic also reset the ECM, BCU to factory settings. Reprogrammed the MAF as well.
I also rebuilt the XYZ or Neutral Safety Switch. Very easy to do. If you see some of the tops of the rivets have popped off, you can clean and rebuild with screws and nyloc nuts easily. I believe it was coming apart and the internal mechanism was off a bit which was not allowing it to send the proper signal to the BCU.
also, are you positive you have fuel pressure? The wires and coil packs are good?
Last edited by CollieRover; Nov 20, 2018 at 08:17 AM.
Alright fellas, here's an update. Did a compression test and that came out good, so no valvetrain issue. While I was at it, re-checked spark and noticed it looked real weak. The first time I checked it with an extra spark plugs and. This time I checked it with one I had just pulled; all the plugs are fowled up.
I cleaned them on a wire wheel and stuck them all back in. I tried to start it up again. It sputtered and coughed, backfired, and finally kicked to life.... Kinda. It was still sputtering. I tried feathering the trottle and got it to run REALLY bad for maybe 8-10 seconds. Kept trying to start it and didn't get any better results, regardless of throttle position. Tried pouring some gas down one of the intake hoses and still no better results. Some sputtering, backfiring out the intake, etc.
Next up is grabbing sensors and computers off my Disco to pop into hers. Would love to hear any more ideas anyone has.
Have you tired some gas additives or maybe seafoam or injector cleaner?
Are all of your sensors getting a good reading at an ultra or scangauge? The wiring for the MAF, Temp Sensor are in the same locale, maybe there is damage somewhere to the harness? Do you have a scan tool you can reset the ECM? Could water have gotten to the ecm or bcu? They're all Tranny codes maybe there is some wiring damage to it?
The XYZ Switch is an easy fix.
Last edited by CollieRover; Nov 21, 2018 at 06:49 AM.
Well gentlemen, after more than a year of sitting I loaded the old girl up on a trailer and brought it from the in laws house to my own so I can get working on it again. To begin my diagnosis I topped off a fresh battery and dropped it in. Hooked up my timing light to confirm spark on each cylinder. Then, when I went to crank it, it fired right up.
I'm dumbfounded. My best guess is that the battery in it before was just a hair to weak to make the electronics work right even though it would crank and crank. I've since put a farm use tag on it and threw some minimum liability insurance on it and drove it 20 minutes each way to my parents house and back. So far so good. I'm going to go make sure it starts now this morning since it's cooled off, but so far so good.
If it keeps running without issue this will pretty much be the conclusion to this thread. If not I'll update and let you all know what happens.
Well gentlemen, after more than a year of sitting I loaded the old girl up on a trailer and brought it from the in laws house to my own so I can get working on it again. To begin my diagnosis I topped off a fresh battery and dropped it in. Hooked up my timing light to confirm spark on each cylinder. Then, when I went to crank it, it fired right up.
I'm dumbfounded. My best guess is that the battery in it before was just a hair to weak to make the electronics work right even though it would crank and crank. I've since put a farm use tag on it and threw some minimum liability insurance on it and drove it 20 minutes each way to my parents house and back. So far so good. I'm going to go make sure it starts now this morning since it's cooled off, but so far so good.
If it keeps running without issue this will pretty much be the conclusion to this thread. If not I'll update and let you all know what happens.
If you have issues again, check the fuse box under the dash. Sounds weird, but the discos have an issue with corrosion in the fuse box which causes all sorts of issues. I had an issue with not starting and it took me forever to find it was the fuse box. I had spark too, but it was weak.
Hey all. I'm back with an odd issue. My girlfriend's Disco won't start. It was running great one day. The next day they went out and no start.
There were codes, but unfortunately I forgot to save them. One was an XYZ sensor code, a MAF code, some others. The battery got unplugged and the codes are gone now, unfortunately.
I have pressed the inertia switch, flipped all the relays around that will cause no start, and I checked spark. Only on two cylinders cause it was raining and 40 degrees, but the spark was strong and consistent.
I've tried starting it both with and without the MAF sensor plugged in. It seemed to sputter and try to start more with the MAF plugged in, but nothing conclusive either way.
I also had my girlfriend try to crank it while I squirted some starting fluid down the throttle body. No luck there either, though the battery was nearly flat and it was cranking slow, so we'll charge the battery back up and try again on that.
If anyone's got any ideas I'd love to hear them. I don't feel like it should be a compression issue or a valve train issue since it happened overnight. Nothing sounds a-miss while cranking. I haven't tried pulling the plugs yet to see what I can tell about them; that'll be next weekend.
Thanks all.
If these conditions return, try to start your Disco in Neutral instead of Park in case there is a mechanical issue lugging down the motor at low RPMs.
