I just returned to the US after 2 years overseas. I had my 1996 Disco 1 in storage for that time at my brother-in-law's place. After replacing the battery (and killing and removing the multiple wasp nests and mud dauber nests in the engine), I used my Bluetooth OBD-II device to search for engine codes. Here's what I have:

- P0125: insufficient coolant temperature for closed loop fuel control
- P0300: random/multiple cylinder misfire detected
- P0307/P0305/P0301: cylinders 7, 5, and 1 misfire detected
- P1316: Unknown Diagnostic Trouble code
- P0420: Catalyst system efficiency below threshold bank 1

My vehicle definitely runs kind of rough right now. I drove it 3 miles to the gas station, filled it with premium, and drove it back. The engine makes a "snap/crackle/ticking" sound with the occasional "wump" that might be fuel igniting somewhere in the exhaust (I have no idea, just a guess). I drove it today for about 15 miles roundtrip and ran the A/C just to see if it worked - it did. Interestingly enough, it seemed like the "snap/crackle/tick" went away when the A/C was running, but I'm not 100% sure on that.

This Disco is the first vehicle I have ever worked on - changed fluids, wheel bearings, window motors, etc., but my overall mechanic skills are pretty much at super novice level. With that in mind, here's my plan:

1) Add coolant until I'm certain that it is at the proper level.
2) Replace all spark plugs and properly gap them (I've never done this before so it's about time I learned)
3) Ignore the catalyst system code because I live in an area that doesn't do emissions testing.

Is there anything that I'm missing? Should I be doing something/anything else? thanks!

 

I would think drain and refill all fluids, air filter, fuel filter, thermostat, spark plugs (easy to do) serp belt maybe, probably more im not thinking about. The snap crackle tick is probably out of my league but others will chime in and guide you in the right direction.

Great video for the others:

 

I wonder what the fuel in the tank is like. If you can drain that and put in fresh fuel you'll be better off.

As stillruns said, drain and re-fill everything. Plugs and wires too. Filters...air, fuel, oil.

clear the codes and see what comes back.

FYI, all the manuals, including the GEMS_OBD, can be found in the link in my sig (it has all the trouble codes and how they are triggered). Help yourself to whatever you like. You'll need them eventually.

Welcome back!

 

Hi everybody, thanks for the tips. I'm waiting for the fuel filter to arrive and then I'll do that next weekend along with the gear oil. I changed the oil, ATF, did a brake bleed, and topped off power steering fluid last night. Here's the thing - I had the hood up and was putting everything away in the garage and the ticking noise was still there. It sounded like a high pitched machine gun on cyclic fire. In the dim light of the garage, I saw a blueish-white spark arcing around the spark plug wire in the back. The sparks synced with the sound of the ticking/machine gun noise. From what I can tell, it's the connection between spark plug wire #6 and the ignition coil, based off the picture from post #8 on this thread. While I don't have any misfire codes for cylinder #6, I do have misfires for cylinders 1, 5, and 7. This leads me to believe that cylinder #6 is firing properly, but the spark may be arcing across and zapping the ignition coil connections with wires #1 and #5, and I guess this somehow some way throws off the "balance" or the "chi" of the left side of the engine.

My new plan of attack (in addition to the upcoming gear oil change):

1) new spark plugs x 8
- 1a) I'm putting the vehicle back in storage in August, so I'm just going to go with the cheapest ones from Advance Auto parts, unless you recommend against that.
2) new spark plug wires x 8
- 2a) I plan on going with 8mm wires from here unless you guys recommend just going with a cheap set from Advance/AutoZone/etc.
3) new ignition coil - quantity unknown?!?!?
- 3a) I looked at Rockauto.com and a single ignition coil ranges from $7.76 - $41.79, with most in the $22 range. Do I need to replace just the one ignition coil? Or all 4 ignition coils? Since this should be more of a permanent part of the engine (as compared to spark plugs, or oil filters), should I buy big and expensive now?

For context, I'm putting the vehicle back into storage in late August. Between now and then, it'll be my daily driver, probably no more than 200 miles per week. I might attend a conference in Kansas City in July, so one roadtrip of approximately 1600 miles roundtrip. If I do any trails, it'll just be light stuff, nothing to crazy since I don't have time to make mods or get all my camping gear sorted and prepped. Next summer and fall (from about August through January), I'll have to drive all over the US and I'll probably rack up a lot of miles. I'll have my offroad trailer with me (a converted M116-A3 trailer) and as I criss-cross the US going from one 2-week rotation to the next, I plan on hitting every trail I have time for.

So buy big now and hope nothing rots away during the 10 months the Disco will be in storage and unused? Or buy cheap now and replace with the good stuff next year?

Thanks everybody!

 

I forgot to add that I cleared the codes and the coolant code went away (probably because I actually topped it off!), but all the misfire codes are still present. I didn't drain the fuel tank because I intentionally left it with only about 1/4 tank. I filled it with premium and have kept topping it off with premium to dilute the old funky gas. I'm considering adding one of those fuel additives from STP, or Seafoam, or something like that. Worth doing or no?

 

I typed up a post earlier but I guess it didn't go through. I discovered that the "snap/crackle/pop" sound was the connection of the #6 spark plug wire to the ignition coil. I discovered this late last night after I changed the fluids in the vehicle. It was dark, and I was able to see the bright spark that synced up with the sound of the snap/crackle/pop. With the hood up it sounded like a high pitched machine gun on cyclic fire. In another thread, I found a picture of the spark plug wiring, and the sparks are definitely occurring at the connection of the #6 wire to the ignition coil. Since #6 is flanked by both #1 and #5, I suspect that the spark is arcing across and affecting those connections, which probably throws everything off in the left bank of the vehicle engine (I'm just guessing, I really have no idea). But this meshes well with the fault codes posted above, with misfires primarily in the left bank (the odd number cylinders).

So my plan is to:

1) replace spark plugs x 8
2) replace spark plug wires x 8
3) replace ignition coils (quantity unknown) - do I replace the 1 faulty ignition coil, or am I supposed to replace all 4?

For context, I'm only going to drive this vehicle until late August, then back into storage it goes until next summer. This summer, it'll be my daily driver, covering approximately 200 miles per week. I may attend a conference this summer, which will involve a 1600 mile roundtrip roadtrip. I probably won't do any offroading or camping this summer - if I do, it won't be anything too crazy, just forest roads and gravel roads. Next year, however, I'll have to criss-cross the US and I'll put a lot of miles on the Disco, from about July/August through January/February for rotations. I'll want to make sure the vehicle is in tip-top shape next year, but this year, I just need it to run and not leave me stranded.

Should I buy the best quadruple unobtainium spark plugs and 8mm wire sets and replace all 4 ignition coils now? Or should I just get the super-cheap plugs and wire sets from Auto Zone, replace the one ignition coil, then next summer put the good Gucci stuff in?

Thanks!

 

Definitely Seafoam it since it sat for so long.

 

Champion RN11YCC gapped .034

8mm spark leads - STI, Magnacore or Kingsborne - all three have fans and haters

Coils - make sure they're cracked before replacing otherwise here's a decent set of four on the rack already (second pic down from top); https://rovahfarm.com/DiscoIIgnition.htm

Techron fuel injector cleaner - you may have misfiring injectors with 2 year old fuel sitting in the rail - next time add Sta-Bil to the tank and save yourself some headaches.

Try the Seafoam before you run the Techron through the fuel system.

 

Another update: spark plugs and spark plug wires have been replaced. I started with the wires attached to the driver side ignition coil (wires #1 and #6), and worked my way across to the passenger side. However, after changing plugs and wires #1 and 6), I decided to test drive it to see if that was the issue - it was. Apparently wire #6 was crappy and simply replacing it was probably all I had to do. I let the engine rest overnight before doing the rest of the plugs and wires because I saw on a video that the engine needs to be cool before changing the spark plugs or else you risk busting the threads. I also didn't want to burn my hands either.

But I know you all know that that isn't the end of my problems - it is a '96 Disco after all. Up until a few days ago, other than the arcing spark plug wire, the engine ran well and powerfully. I could accelerate without any issues from a stop or while driving. I live in an area with hills and mountains and when going uphill, I could always stomp on the gas to maintain speed.

Not anymore. A few days ago, I started the Disco up and as I was gently pressing the gas pedal to start slowly rolling out of the driveway, the engine practically stalled. I attributed this to the darn spark plug wire and continued driving, figuring that it would "correct" itself after the engine warmed up. Then I got onto the main road, doing about 35mph and started going uphill. I pressed on the gas to get some speed but no luck. It didn't matter if I stomped on the gas, there was no acceleration. I discovered that I had to slightly LET OFF the gas pedal before I could get a reaction out of the engine. Even then, I had to let off the gas to get it to downshift, then slightly press the gas pedal to get some speed, then slightly let off of it again, then just continue the cycle over and over. This is obviously dangerous since the Disco is a bit of a dog going uphills anyway.

I have to work the gas pedal back and forth now to get it to move from a stop. I can no longer punch the gas pedal to accelerate quickly when I need to (for example merging into traffic, passing a vehicle, or simply after coming to a stop at an intersection).

My thoughts based on my research on this forum:

1) Unplug VSS and see if that improves anything - part of me wonders if I leaked brake fluid all over the VSS when I did the brake flush a few weeks ago.
2) Check for vacuum leaks - I have no idea how to do this or what I'm looking for, so I would appreciate if someone could point me in the direction of a forum posting or a youtube video showing exactly how to do this.
3) ???

Your thoughts? Any and all help greatly appreciated.

 

3) could be a couple of things but the first I'd check is the kick down cable. Then I'd clean the intake and IACV.