@Extinct Thanks for the info on the ECT. I went ahead and bought a set of the Bosch reman injectors a few weeks ago. The PO of the truck said he was planning to do injectors if he kept it, so I assumed that meant he had reason to believe they should be changed.

The shop will use the parts that I provide, which is nice. The mechanic is also a Rover only guy, daily’s a DII and will open the hood and walk me through everything he did.


At this point I’m not sure what else it could be other than injectors.

Where would you look if you do new injectors and the issue persists?

Should I have them look into anything else? Based on the engines behavior, power level, coolant temps, oil usage, etc, it seems unlikely it’s a deeper motor issue, although it’s always a a possibility.

 

I guess I still have not ruled out the ECU being the culprit. With the information I now have I think that is still a possibility.

 

If the injectors don't get it done I would swap the ECU. Actually I would probably do that first because it is fast and easy compared to injectors. But like everything I keep a couple of spares around.

 

Change or check your fuel purge valve. If that sucker sticks open you get a bunch of issues just like your having. Ask me how I know.
A quick test is to plug the vaccum port where purge valve connects too. You should see improvement after a few miles.
Smoke test is best for exhaust and vaccum leaks
sounds like you have a landy mechanic. Don’t cheap out to much or always bring your own parts. They don’t like it

 

@redwhitekat I think he gets annoyed when I trouble shoot issues instead of just handing it to him and asking him to fix it. But, I also feel like we have a good understanding. I’ve worked in an around the local automotive community my whole life so that helps.

Good idea on the fuel purge valve. I’ll read more about that.

@Extinct, jealous of spares setup. I’d swap in an ecu if I had access, easy test. I bet the mechanic has one at the shop though.

I’m traveling for work all weekend, I’ll respond back when I more on this next week!

 

I dropped the truck off yesterday. Mechanic called me after he looked everything over and seems to think it's the injectors. He is cool with using the injectors I provided so we're going to that and see what the result is. He does not think the injector seals are the issue.

I'll ask about the fuel purge valve when once new injectors are in and we see the results. He mentioned my Cats are dead which I have been suspecting, so in typical Rover fashion I already have my next project identified. haha, time for some high flow cats!

 

I talked to the mechanic yesterday. He I were both thinking injectors when we first talked, but he got the truck apart yesterday, and found a bolt missing in the lower intake, and the rest were not tight.

So there was obviously a substantial vacuum leak coming from the lower intake not being torqued properly. He sounded relieved because he first inspected and tested the injectors and none seemed to be an issue.

Turns out the problem was from the PO who recently put the motor in the truck. Human error is more often the cause of issues than not. Disco's get a bad rap for reliability, but I'm pretty confident most of the reliability issues are because they require more work than other vehicles and that work can easily be done improperly.

Anyway, he still has the truck taken apart. I will pick it up Monday and report back.

 

Update:

I picked up the truck yesterday. The lower intake is properly attached with new gaskets and eight new (Bosh reman) injectors are now installed. I noticed the truck was more responsive and felt more powerful right away.

The fuel trims are still not quite normal, albeit much better than what was shown previously on this thread. Fuel trims are good enough to not trip the SES light, whereas before the truck was throwing Lean Codes P1171 P1174.

I talked to Reid (mechanic) for quite a while when I picked up the truck and we discussed next steps to continue to diagnose the issue. It's obvious that the work he performed helped, but he gave me the old injectors and we both determined that at least visually they appear to be fine (screens not blocked, o rings in decent shape, etc.). It seems likely that the improved fuel trims are coming from the lower intake no longer sucking in unmetered air.

I did a static fuel pressure test which showed good fuel pressure. Reid suggested we might want to do a dynamic fuel pressure test and measure fuel pressure while driving as a next step if fuel trims do not improve. He also noted that the Cats are not quite working properly, and while they are not throwing a code (yet...) he believes they are at least partially clogged. Could be related, but doubtful. Reid is an awesome dude and actively works to keep me from spending needless money which I greatly appreciate. We both decided to drive the truck for a while and let the computer adapt.

Summary: New injectors, no more vacuum leak from lower intake bolts being loose = better fuel trims. Fuel trims are still not perfect, but just good enough to not trip the SES light. They may improve with driving.

Action items: I will log short term/long term fuel trims and post another video.

Possible issues remaining: As mentioned before in the thread, truck has had bad fuel in it. It's very possible the filter in the fuel pump assembly is clogged and not allowing for proper fuel pressure under load. Thoughts on this? Are there other items I'm missing like fuel pressure regulator or something? Are there any possible more major motor issues I could be overlooking? HG's do not leak, truck does not lose coolant, coolant temp sub 200 in all conditions (180 thermo), uses some oil (maybe 1/3 of a quart in 3,000 miles or so, but I commute a short distance and do a lot of short start/stop in town trips. If I do mostly highway miles, oil consumption is not noticeable. This seems very normal to me having driven mostly older cars my whole life). I have not performed a compression or oil pressure test but have not had a reason to. Motor turns over quickly and cranks right up every time. Revs smoothly and now has good power.

Random thoughts: While I like the Hayden Severe duty Fan Clutch, it's so noisy that it's difficult to hear the motor/ induction noise while driving, making diagnosing and assessing a running issue difficult. Since the fan clutch is an easy job and I have the tools to change it, I might go to one of the less aggressive fan clutches. My cooling system is in excellent shape and I feel the additional noise makes the driving experience worse, and makes it hard to listen to the motor. It's also very noticeable that the Severe duty requires more engine power to spin, which is not a huge deal, but it is certainly noticeable when you drive it back to back with another fan clutch as I did.

Final Question: Do you think it's harmful to drive the truck with suboptimal fuel trims?

Thanks for the help so far. Making progress.

 

your fuel trims should even out as you drive the truck and it gets use to not having vacuum leaks.

 

How long or how many miles does it take for the truck to to even out the fuel trims in your experience @jastutte ?