Live Data analysis
- Thread starter AbnMike
- Start date
I'm just wondering where one would even find what the readings should be...they're provided for some reason. The truck runs normally other than I keep getting a P1317 rough line road fault (ABS) code almost daily. I have the fuse pulled on ABS but that code keeps showing up. As you can see my reader is about as basic as they come.
I found the following write up on that code so as soon as I feel like it I'll fix it since it's not affecting anything: https://discoweb.org/forums/showthread.php?t=13311
I did throw a Cylinder 3 misfire and "multiple random misfires" the other day. Checked my plug wires and a few of the plugs and they look fine.
I've got new Kingsborne wires on order since my wires are about 20k old and I heard rovers eat wires. I'll put in new plugs, too.
OTOH I got 10.2, 10.6 and 10.2 MPG yesterday on an 800 mile round trip (the last half of the 10.6 and all of the second 10.2) were pulling a trailer I picked up so good to know the trailer didn't affect MPG at all.
10.2 highway MPG at 2250/2500 RPM and no passing and no sudden starts is still absolutely fucking ridiculous but them's the breaks I guess.
Bonus: It looks (though I haven't measured yet) to have the same bolt pattern as the Discovery. Took 16 hours round trip to get it but the Disco ran fine. Also I was worried the pintle hitch would be noisy - didn't notice it at all, way more quiet that a ball hitch.
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I should've kept my lifted D1 as it would get at least 12mpg actual around town and would frequently crack 14.5mpg on road trips.
I'd love to know how to get those returns.
25k miles ago it got new heads and gaskets, camshaft, hydraulic lifters, timing chain and gears, valve cover gaskets, ignition wires, vacuum hoses and Magnaflow stainless steel Y pipe and catalytic converters
I still can only get +/- 200 miles out of a tank of gas, in the city it's less but I understand that, lots of stop and go driving.
I know I'm carrying a lot of weight with the front bumper and winch, the roof rack, the door mounted spare, but I drive like those hypermilers - I don't floor it at lights, I don't keep the gas going and then slam the brakes. When going uphill yesterday I would get into 3200 rpm when it down shifted and only once or twice got into 4200 rpm. I kept a close eye on it and I was at 2250/2300 RPM for 85% of the trip. I use momentum going downhill to plan for uphills, etc.
Same brand of gas: Exxon Supreme (or whatever the highest octane rating is branded).
I'm wondering if my adaptive values are all screwed up? It came from Washington State, then moved to Montana (5500' elevation) and now am around 1200' elevation. The MAF has been cleaned with cleaner. Air filter is clean (run a snorkel so air is fresh and cold). Oil is changed regularly (larger PUROLATOR #L40316 filter with Rotella 15/40 oil, but going to the 5/40W for winter per the recc on Land Rover Forums tomorrow when I change oil again - ran Seafoam in the crankcase on my way back the last 200 miles).
Tires are BF Goodrich Radial MT KM 2s 255/85/16 - proper inflation (had it at a higher PSI but went back down after too high psi was affecting the steering, making it twitchy).
Only thing I haven't done is new wires and plugs, but I'll try that even though my wires are 8mm and running the correct Champion plugs but they are 20k miles old.
An extra 5 mpg yesterday over 800 miles would have saved me a fair penny or two in gas costs.
When I bought my first 98 D1 in 2004 if got 20 driving to CO from VA. In CO it got 18 on the highway until I lifted it and out on 235/85s and a rack. Then it dropped to 14-16 depending where you were driving. These were straight highway numbers. Even after the 3" lift and 285 mud terrains it wasnt much different. I think your trucky is fucky.
Wires and plugs like Stu said? Anything else to look at? How do I know if it's running too "rich" and how to make it not run as rich?
Could the injectors just be dumping fuel? I would think if so there'd be other symptoms though - it idles smoothly, downshifts smoothly, on flats I could cruise at 70 mph at 2250-2500 rpm, etc.
Your short term fuel trims are OK, but long term seem high. Anything under 3% is ideal, 5% is reasonable, but you're at around 13% (max is typically 20% before it can no longer adapt). I'd be concerned about a vacuum leak.
Also, is the truck idling, or are you holding the throttle partially open? The engine rpm is 842, which is too high for an idle, and the throttle indicates ~15% open. The two numbers roughly correlate, as long as you're holding the throttle when the measurements were taken.
Also, is the truck idling, or are you holding the throttle partially open? The engine rpm is 842, which is too high for an idle, and the throttle indicates ~15% open. The two numbers roughly correlate, as long as you're holding the throttle when the measurements were taken.
Wasn't holding the idle. As I recall this was at initial start up when cold. At least I don't think I had my foot on the pedal. I'll redo it and see what it says.
This is a photo of the tailpipe, that ring around it is pretty black.
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that is what my '96's tail pipe looks like. 220,000 miles. it gets 10-11.5 around town and 14.5 straight highway.
2.5 inch lift and no armor or extra weight. and all original engine. it is probably due for new plugs and wires.
i've had good experience with the 8mm Kingsbourne wires and will use them again.
it does seem like something is off with your engine. but who knows. after being on the these forums for several years and reading all the MPG threads there really doesn't seem to be any rhyme or reason to how much fuel these trucks drink. some guys claim 18 MPG highway and some never see above 14 MPG highway. even on similarly set up trucks.
Strange. I'm at 172,000 miles btw with the above mentioned top end work done 25k ago.
I'm not throwing any codes. The only codes I ever get are the Rough Road Line Low Fault P1317 #E8 Apparently that's an ABS issue.
If the 02 sensors were bad wouldn't that throw a code?
Not necessarily. O2 sensors can give incorrect, but plausible, values.
As I mentioned earlier, I'd be looking for a vacuum leak. LTFT indicates your fueling system is dumping excess fuel in to compensate for something. Since both banks are giving similarly high values, either the O2 sensors on both banks failed in a remarkably similar way, or they're giving good data based on input that's being affected upstream.
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I'll try to see what I can find. All the rubber was replaced recently, engine compartment is clean, etc. I'll do some checking on it all once I can get back into the garage.
I forgot to add:
Couple weeks ago I noticed that my exhaust manifold was loose at the motor (both sides - the bolts had backed out). In addition the manifold to exhaust gaskets were burned through. I replaced both of those and tightened the manifold bolts back up. I'm sure that was screwing with the 02 sensors, but again - no codes were thrown. I only noticed it because I did a Seafoam treatment and saw smoke coming out from all over the place.
However that has been a few weeks, many on/off cycles, and my battery was out for a couple days to recharge, which should have reset everything right?
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I get 200 miles per tank in town on my D1, highway I get 340. No off-road accessories, running 235/75/16 (30") AT tires. New O2 sensors, new plugs, new wires.
I, too, would be interested to know if there is a reference somewhere that shows what operating ranges are ideal for the D1 based on the OBD2 reader's live data. The only thing I use mine for is watching the coolant temp. I don't know what other readings mean or now to interpret the numbers displayed.
I, too, would be interested to know if there is a reference somewhere that shows what operating ranges are ideal for the D1 based on the OBD2 reader's live data. The only thing I use mine for is watching the coolant temp. I don't know what other readings mean or now to interpret the numbers displayed.
The leaking manifold gaskets would align with the LTFT values being high positive, and short term being negative. (you had a long standing issue with leaking exhaust leading to diluted O2 values - after it's resolved, the engine recognizes that it doesn't need to dump as much fuel to compensate)
LTFT values can take a long time to change. I'd monitor over a couple of weeks and see if things are moving in the right direction.
A couple of general notes:
1) All parameters should be monitored at normal operating temperature. Unless you're looking for a warmup-specific issue, looking at cold values can be somewhat misleading, as you may not even be operating in closed-loop yet.
2) OBD2 measurements, acceptable values, etc are very similar for a wide array of vehicles. I won't say there aren't any differences or vehicle-specific peculiarities, but I don't know of anything special for the Discovery in this regard. A bit of general online research on OBD2 measurements (fuel trim, O2 voltage, timing, etc) will give you some good guidance. Again, nothing Land Rover specific.
LTFT values can take a long time to change. I'd monitor over a couple of weeks and see if things are moving in the right direction.
A couple of general notes:
1) All parameters should be monitored at normal operating temperature. Unless you're looking for a warmup-specific issue, looking at cold values can be somewhat misleading, as you may not even be operating in closed-loop yet.
2) OBD2 measurements, acceptable values, etc are very similar for a wide array of vehicles. I won't say there aren't any differences or vehicle-specific peculiarities, but I don't know of anything special for the Discovery in this regard. A bit of general online research on OBD2 measurements (fuel trim, O2 voltage, timing, etc) will give you some good guidance. Again, nothing Land Rover specific.