Steveastrouk

Does that need to be a dealer ? Or can it be done from a generic OBD ?

Just to finish this thread. After consulting with a very wise and ancient mechanic who took one look at the OBD codes and said "Lambda probes" I gave in, and bought my son a set of 4 generics for Xmas. I also straightened out some tiddle-poor crimping of wires on his recently replaced fuel pump while I was at it. Had to cut one of the probes out, and make a new mount in the downstram pipe for the passenger (NAS spec) side. Car is runnng like a champ now. Idle is still a little too high, but the car has only been run at length for a couple of times. I assume it needs a few more before the ECU will settle again. Learned a lot from you guys in this thread, I appreciate all your comments. Steve

Will try that in the morning. It also occurred to me, that given him rolling the bloody thing, I don't know if the plenum has crud in it too.

Not vacuum leaks, blew something nice and volatile at it, didn't twitch except when I blew a sniff in the inlet itself. Airbox and environs on the list to look at tomorrow. No sign of the throttle linkage sticking or anything simple

CLEVER ! Thanks guys. We're about to get whacked by the tail end of that hurricane Isias tonight, so that's a tomorrow project, weather permitting.

Engine DIDN'T run upside down Steve

THAT'S an interesting idea. Are there are procedures for vacuum leak testing - I've vacuum bled brakes, but I have never looked engine systems and vacuum, Thanks guys

Also, I notice the thing has a VERY high idle, in Park - like 2800 RPM. Could that be a symptom ?

So dad (me) finally got to drive the thing extensively today - another suggestion received elsewhere was a glitchy VSS, so I removed that for a try out, and still no dice. What I experienced with it though wasn't "loss of power", I had outright misfiring. Bringing the car to the side of the road, and idling it doesn't return the power. Switch off, and immediately restart - bang, we're off again. I'll clear the codes on the OBD and try tomorrow. Thanks for all the ideas, I'm still leaning to the fuel pump, going to underneath and look at all the wiring tomorrow.

Going to go under it and explore tomorrow. What gets me is that it is instantly fixed by turning off the ignition. I need to wiggle nothing to make it work. Shorts are entirely possible.

He did both fuel filters for sure. Oil looks OK, Battery is still nicely tied in. Checked the ECU wires too. Air filter needed changing, that was done. I think its the intermittency that gets me. Driving it back, we had a couple of hours with nothing, then not more than 20 minutes of driving between issues. It might've correlated very very slightly with the level of fuel in the tank, I don't know. <edited> Now he adds that JUST before he had the rollover that he had one episode of this, so that event might not have been the trigger. Sorry, wasn't aware of that earlier. There was a lot of oil in the filter after the roll. Would O2 sensor failures give us an issue like this.

Hi My son rolled his pride and joy, his 1997 Disco 1 NAS spec 4.0 while recovering the car from a desert track where he'd had to replace a draglink in the field. He let it sit for a few days for everyhing to drain back into the right places, then was forced to leave his school because of Covid and come home. On the 2000 mile return trip he kept getting weird powerlosses, which we couldn't resolve, they didn't correlate with hills, high speeds or anything else. He was in such a bad state, his mum and I drove out 500 miles to meet up with him and help. I experienced the same thing as he did. The weird thing here is that when we pull off the road, turn off the ignition and IMMEDIATELY turn it back again, the damned thing purrs like a kitten and we're on our way. NOW, full discloseure, fairly recently he'd burned out his fuel pump (student cash flow crisis- ran it dry) and replaced it with an after market pump. I'm still seeing decent rail pressures, and no leakback when the ignition is off, but we have that as a contender. Next, the local autostore ran the OBD on it, and we get P0451 and P1316 - I'm very suspicious of P0451 - fuel pressure sensor fault. Would that give us the symptoms ? There are defintely wire issues back there. Thanks for any input you can give us. Steve

I took the box to work, and reflowed the whole thing in our special ovens, but it hasn't fixed the problem.

No, this is a NAS spec Disco, with the GEMS 4.0 engine.

Ah well, It wasn't the power. We can make it work always, if we disconnect the alarm box completely for 10 minutes. Does that give anyone any ideas, because I'm out of them.

In case anyone else has similar problems, it was failure of the wiring to the ECU fuse F3. That removes power from the ECU and the top of all the coil packs.

Tried to put an oscilloscope on the security code wiring at the weekend, but we couldn't get the ECU to fault ! That may in itself be a clue.

Can we link something out to disable the immobiliser box ? How about the ECM main relay not switching properly ?

Are we betting on some sort of problem with the alarm box- ECU then ? Steve

Thanks for all your helpful tips guys. We have pressure, but no spark, when it won't start. Its GEMS for sure, and it has coil-packs. It doesn't ALWAYS start cold, but it never restarts warm I believe. Like I think I said, the thing STARTS when the check engine light is lit, and doesn't when it isn't.

Looks like we didn't get the fobs. We had to put a new ignition switch in already, because the original was worn out. Can the alarm box be patched out, or is it chatting to the ECU all the time ? Is it realistic to think we can find and fix it, or should we just put a new megasquirt unit in ?

I'll have to check I have a feeling we didn't. Interesing about the alarm ECU. Is that the module in the doorpost ?

Thanks BM. I was under the impression, though I may be wrong, that NAS spec Landies with that engine didn't HAVE the alarm spider thingy ? Its all turned out to be very confusing, and I am very inclined to say bugger it and put megasquirt in. Thing is, sunshine wants to drive to his new uni in New Mexico, and expects to offroad it, so I want it to be reliable. Ex-pat Steve PS. Is there a way to tell from our VIN PRECISELY which engine we have ?

I bought my 18 year old son a 20 year old NAS Discovery 1, which turned out to be a much bigger project than we expected. It was originally from Vancouver, and meandered its way from there, through California to Central Pennsylvania over the last 20 years, where I suspect it expected to rust in peace. We've put 6" of new metal virtually all around, courtesy of YRM Metal, new crossmember, new inner wings, grafted steel around the Alpines, new passenger floor, major patches in the driver footwell. And right now the bugger won't start. For much of the time. Son ran it today, and it ran like a champion for two hours. Then he tried to start it 10 minutes later, and we get lots of cranking, we get fuel rails to pressure, but we get no bangs. One interesting thing is we get a check engine light ONLY when it starts, and not when it doesn't - I am thinking ECU isn't getting power, sometimes. I'm lost for things to poke at. Does anyone have any suggestions we can look at ? Thanks a lot. I'm very grateful for any tips you can give me. Is it worth ripping it out and putting a MegaSquirt system in ? Steve

Hi Mike, Ironically I've just found this post while looking for bits to do another LHD 101 with your PAS conversion. I've still got 62FL19, and I've just put him back on the road after three years off it. I was looking for guidance on the drop arm you used ? I'm emigrating to the USA on Saturday, and exporting both my 101s, but the ambi needs the PAS conversion - because she's got no steering box at all. I'm coming back to the UK in a month or so, so I'll finish the work then, but I'm trying frantically to gather the bits so I'm ready when I get here. Steve