Codes are
P1412 P1415
P0171 P1171
P0314

Just finished a valve cover gasket job to fix an oil leak and this is what I'm getting. Before the job, I just started getting an occasional secondary air fault and 02 sensor fault(wrote the codes down but cant find them, attributed this to an exhaust leak I have on the passenger side bank 2) and once a month getting a P0441 (replaced the purge valve and the code slowed to this, now I just deal with it).

I am assuming the P1412 and P1415 are just a bad connection somewhere and when I inevitably have to take the upper intake off again I'll deal with it then.

The P0171 and P1171 are the codes I am having an issue with because they are making bank 1 go full rich and dump fuel, and we all know how valuable fuel is now. All four 02 sensors were replaced 10K miles ago as well as the MAF, all bosch parts. I was recently told that bosch o2 sensors were kind of iffy on getting working ones straight out of the box but mine have been working for over 10k miles now(I believe about 2 years), and I am just now getting a problem. I do not believe the 02 sensors to be at fault here because of the fact they have been working fine and are relatively new, coupled with the data that I have taken from the truck. The following graphs are the upstream sensors and the downstream sensors from a cold start, warm up, onto the highway, and as I get off the highway, bank 1 plateaus for the rest of the drive, fuel trim shoots to +25% . The sensors appear to work fine until I get off the highway. I will also include the the raw excel sheet of data that contains much more information should you like to take a look.

With all that said, I fought this same issue Juneish of last year (led me to change the MAF) and couldn't find anything. Tried making a smoke machine to check for vacuum leaks but couldn't build thick enough smoke inside the intake and quit, went to move the truck and then the issue has been gone since.

I am ultimately thinking that the only thing I haven't touched and cannot inspect with the engine together is the fuel injectors. I have heard of people selling trucks chasing a vacuum leak and turns out the fuel injector seals just needed to be redone. I have worked on a lot of stuff but never touched fuel injectors. I can not really seem to find any threads relating to resealing them, with from what I gathered are just O-rings. Do I need to replace all the injectors or do they sell a reseal kit? or maybe just a generic size O-ring will work? Should I do any special cleaning or service to them while they are out? Not sure on any details of this job so any info appreciated.


Upstream sensor data

Downstream sensor data

 

If you're going to replace the o-rings, I'd replace the micro filters and pintle caps while you're in there. Use some clean engine oil to lube the o-rings so that they pop into the lower intake manifold and fuel rail without issue.

Alternatively, you could have your injectors sent out for servicing. While replacing valve cover and valley pan gaskets, I sent mine out to RC Fuel Injection for cleaning and balancing. It was $200 (plus return shipping) for all eight injectors, but they also replace the o-rings, micro filters, and pintle caps while they're at it. Took about a week from the day I sent them out to the day I got them back.

https://landroverforums.com/forum/di...leaned-106320/

 

Appreciate your thread and testing out that service. What issue were you trying to fix that led you to servicing them? Also I assume that issue was fixed, but was there a noticeable gain in performance as well?

I believe the fuel rail can be removed without pulling the lower intake manifold. I have never pulled the lower intake but is it known to leak? Worth it to replace while I am in there?

Gonna look into that company for a rebuild but may opt to just get new ones for the price and hassle, is there a specific brand I should look for or are they all the same?

thanks for the help!

 

I didn't have any issues with my injectors. It was a case of "while I'm in there..." that got away with me. Gave me an opportunity to try a service that I'll use for future projects. I was surprised at how bad a couple of injectors were and how big of a difference in flow rate was betweeen them all.

I recently put my engine back together after months and am currently burning up old fuel. I'm hoping to have fuel economy numbers come next weekend.

If o-ring, filters, and pintle caps are all you want, I went through The Injector Shop for those parts (before I had my injectors sent out for service, which replaced them anyhow). You'll want:

-Bosch Type 3 Fuel Injector, Lower O-Ring Retainer Pintle Cap Kit
-Universal Fuel Injector Micro Filter Basket 6mm x 12mm
-Fuel Injector Viton O-ring Seal Kit for Bosch, Siemens Fuel Injectors Universal

 

Very good! Interested to learn your numbers before I move forward. Are you running premium fuel? I was averaging 14-16 on the highway a few months ago with premium fuel, no lift and “all terrain” tires. I’ll check this thread and your thread in about a week for an update if you wouldn’t mind.

thanks!

 

Before I did all this work, my D2 was pretty stock apart from a genuine 180F thermo, Magnaflow y-pipe, and running LT245/75R16 Cooper AT/3 tires. When I pieced it back together, I also had Extinct's inline thermo and Best4X4 PCV mod done, and replaced the air flow meter and entire ignition system. The viscous fan hub is also fairly new. Anyhow, before my mileage was 11-15mpg. I've got a road trip towards the end of this week that'll give me a chance to put some fresh fuel (Shell 92 octane) through. Hopefully, the D2 won't give me anymore surprises.

 

I had to push back my planned road trip to next week. However, I did drive about 200 miles today on mostly country roads maintaining speeds between 50-65mph after filling up from 1/8 tank. Refueled again after the trip. Managed 17.66mpg. Next week's trip will be mostly freeway (65-75mph) over about 400 miles. If I clock in over 15.5mpg, I'll be surprised.

 

I think 17.5 is doable under 65 mph. Speed kills mpg. I managed 16+ mpg keeping mine under 70 mph on a road trip. Above that and it will drop off fast imo.

 

I agree. I'm interested in seeing what my D2 does next week on the freeway. Of course, having the injectors cleaned and balanced for fuel economy isn't the right tack to take. My injectors were pretty bad. Flow and spray patterns were varied. I used to have an audible tick that was engine speed dependent. It's no longer there after putting everything back together. Not saying that having the injectors serviced was what resolved that ticking, but it seems like the most probable cause.

 

Almost exact except slightly wider Cooper Discoverer RTX tires, standard 180 thermo, and stock exhaust, although I do have an exhaust leak on the passenger side ypipe - manifold connection.

I did do mpg tests back when I was running perfect with shell and standard premium and what I found was shell had a negligible impact on fuel economy compared to anywhere else premium. Whether it keeps the engine cleaner I cannot say as I didn't have the boroscope then and couldn't check out the cylinders, all though that would be interesting to study before and after a few months of use. Anyway, the point is with gas prices now, definitely will not be paying shell's markup now and gonna be redoing my study between a month each of premium, plus, and regular. First tank is for the computer to adjust timing and the remaining 3 tanks for actual mpg data.

Very cool that you you managed over 17.5. Can confirm that these things are just about as aerodynamic as a billboard, my mpg drops off steep above 65. For long trips not really ideal to go that slow but for a highway drive to work, the extra 2 minutes might be well worth it.

I opted just for the fuel injector parts and some carb clean after doing some research on how they are cleaned and reworked. Assuming all mine are working correctly, just back flowing some carb cleaner under pressure through them and then running it forward to verify spray pattern are similar between all of them should be fine and saves me a few hundred.

Just curious what you guys think, has anyone ever had the lower intake manifold to head leak air? Curious if I should swap it while I'm down there since I am chasing an air leak that can't even be confirmed to be fuel injectors. Doesn't seem like to much extra work considering the fuel rails will all be pulled anyway, let me know