re; Voltmeter?

Yep, you can get a more precise reading, I've got a five digit Fluke that is about $600. But do you want to have four of them hooked up to long cables into the passenger compartment so you can ride down the road? The last little fraction of a volt means something on a cruise missle. Not so much on a British tea kettle with a security complex (my owner has such valable test equipment we need this alarm system to immobilize the vehicle because the battery degraded .98764 volts).

Main thing for most people is being able to see (a) - it is changing (most control systems are not static, and un-changing values are always something to look at) and (b.) that readings make sense and are not far out of range, and (c.) values move in concert with each other.

Ultra Gauge is on my list for Santa

 

I actually had to view the vids a few times, to see the O2 volt readings, and read through the posts. The upstream O2's should fluctuate according. The down stream readings, will remain almost static, but should fluctuate a little.

Bank 2 / O2 1 - Bad: "Bank 2 O2 1 stays at 1.020", it is static and not reacting to sudden changes, BNK-2/O2-1 reacted correctly

Bank 1 / O2 2 - Bad: From the vid, this one sat at .5, while BNK-2/O2-2 reacted to the changes

Note: I looked at my readings from my Dodge Magnum / Hemi engine, same O2 configuration. I look at the readings and understood how the signals change when under load and at idle.

The upstream O2's provide the initial feedback to the ECU to constantly adjust the trim of the fuel to hit that sweet figure 14:1. The downstream O2's read the result after the catalytic converters, providing the feedback to the ECU that the all ratio's are with the correct parameters.

Back in the days, it was so much easier to tune with just 2 or just one O2....jezzz....

 

Wonder what the result would be if you moved the static one from the front to the rear? I have read that only the fronts on the Disco affect fuel input and the rears merely signal if cats are out of tolerance.

Thanks I wouldn't trade it for anything. Not even an FZJ80

There are a few things I would trade mine for: another W126 or early MB SL,
another Z car, or a short list of other desirables.

 

Very true and don't get me wrong they are neat little accessories to have, especially for the price. If you want a general picture of what's happening they rock. All I was saying was that if he needs exact values and readings, a second reading would be a good idea to be sure the ultra gauge is 100 percent dead on. You have to be careful with those things in some cases because the readings aren't always correct. I've had one program on my racecars read 5 degrees off on base timing and even further off on a/f ratio. Switched to the old program I knew was accurate and learned my cheapo software had a glitch. Double checking in my case was the difference in a sub 5 second 1/8 mile pass or a nasty nitrous backfire that could have destroyed my engine had I trusted my brand new el cheapo engine management software. I realize that doesn't apply here but measure twice cut once is always a good idea.

 

Well I replaced the two pre-CAT O2 sensors and now the values are happily jumping all over the place and the fuel trims look much better. I'll replace the post-CAT sensors eventually too. The new (again) plugs and IACV come Monday.

However the loss of power thing that just popped up at the end of the last video is continuing. We went for about a 70 mile drive in town and on the freeway. No matter the speed, it randomly cuts out, and loses nearly all engine power and limps along. It lasts 1 second to a few minutes. Luckily on the freeway it only lasted a few seconds at a time. Now what?? VSS?

 

That's a prime suspect. It is a reluctor style sensor, bolted to hard to get at spot on transfer case. Might check wiring connector (water, corrosion, loose). Do you have a scanner or ultra gauge, where you could monitor vehicle speed from ECU? It comes from that sensor. Don't know if the signal processing in the speedometer cluster cleans up the raw data before it goes everywhere else, or if what you see from ECU will change when the main thrusters are failing and the Klingons are closing fast (oops - wrong video). seems like if speedometer suddenly dipped, you would notice that, as male human instict is to immediately scan instruments, following in a microsecond by the off color language associated with impending mechanical failure and wallet weight reduction. But there is a circuit board in the cluster that may keep the speedo working even if signal is flakey. The ECU thinks you are exceeding 114 mph, and begins to govern speed by turning off injectors and spark, perhaps one at a time.

What about your short burst of white smoke - same? Any coolant loss?

 

Yeah I got the ultra-gauge, remember old man??

No codes so far. I do need to pay attention to the MPH when it does it again because every time it did it I was looking at the TPS, O2s, timing adv., etc. They all looked good. Or maybe I was too busy cursing and looking at the pissed off drivers behind me

 

Someone correct me if I'm wrong but couldnt you just unplug the VSS and see if the problem goes away? I'm not sure how that system works in Rovers, but most vehicles do not need the VSS plugged in to run. It will kill your speedo while its unplugged and you wont have a governer, but if the problem doesnt show up you'll know what the issue is.

A lot of drag racers have that problem on cars with ton of power that still have the stock ECU. They simply tap into the VSS wire and add a switch to turn the system off for race day.

 

I did pressure wash the underside recently and it's been well below freezing at night and some of the day. I'll try spraying it out with CRC electric cleaner. Worst case if I get stuck I'll unplug it and hope that was it, or I'll still be stuck and know it wasn't.

 

Oh Buzz you asked about the coolant level. It's gone down about 3/4 inch over the past week. Some of it has to do with the brass radiator plug leaking around the threads. I should probably use some teflon tape on it.