long crank cycles and random bank 2 only misfires on start?
 

Full disclosure, I'm re-posting this from landroverworld.org as I'm hoping to pool knowledge from all the JLR 5.0 folks!

Ok folks, I've been trying to locate this particular gremlin, and I'm hoping someone else has experienced it. It started shortly before I swapped my chains out roughly 25K miles ago...or about 3 years ago. (Yes, I've been trying to sort this for a while)

Here are the symptoms: When it's cold, it'll crank a little longer than normal. Then, when it "high idles" after startup, it idles rough. Then, every now and again I get a "misfire on cyl 2,4,6,8" "random misfires on startup" and "misfire detected on start up first 1000 revolutions". Once the engine is hot, it typically fires right off, only hesitating every so often. I can't seem to find a pattern as to why it only struggles to fire sometimes vs. others.

Now, here's everything I've tried...some of this was preventative in nature, and some of it was me trying to track the issue down.

New chains, tensioners, injectors, coils, cam variators, plugs, gaskets, front and rear crossover tubes, thermostat, pcv valve, intake smoke check, new cam position sensors, new crank position sensor, new oxygen sensors (all 4 of them), new HPFP, new LPFP, new MAF's, new MAP, new intake VVT solenoids on both banks, removed and resealed the valve covers, removed timing covers and re-checked engine and fuel pump timing, new alternator, new PCV diaphragms, new battery, new radiator (probably not related, but thought I'd include it)....I think that's it. (there's other projects, but they're infotainment and driveline related)

Things I know: The coolant temp sensors appear to be reading correctly based on outside air temps and prior to start they all agree. The long term fuel trim on bank 1 is -8.6% and on bank 2 it's -12.5%. This can be seen by the fact that the bank 1 injector pulses are approx .0001s shorter. aka Bank 1 is .00125s and bank 2 is .00118s at idle. All the other readings appear to be normal...with the potential exception of the throttle body...maybe (explained below).

I've found something online that pretty much says what I have, but you have to pay the site to access it, AND you need an ASE certification to see the "solution"....if there even is one! What a bunch of crap!

The site is here in case anyone belongs and can see what they came up with:

https://diag.net/msg/m5aig315ghghovxbkbh84vh52y

I'm almost at the end of what I can fathom it being, but I have a few more ideas I wanted to run by everyone:

1. Cats are a little clogged up? Maybe just enough to cause a miss at low rpm, but flow enough when the throttle is open a little and they're hot. (Gotta admit, I kinda just wanted to swap the cats out for 200 cell cats and re-do the exhaust anyway)

2. Throttle body needs to be re-calibrated. I've cleaned it a few times....and there's a chance I swapped it with my other LR4 when I had it off, honestly I can't remember. That said, I noticed the commanded and actual values, along with another "position" value were different when looking at live data on my GAP tool. ( I meant to screen shot the values and forgot)

3. I haven't replaced the exhaust cam solenoids, may?.....that said, they're always pretty close to each other and seem to schedule the VVT just fine, so I don't really think it's them.

4. Engine PCM - I've heard these can start to go bad. However, I feel like the engine just wouldn't run, or would be really crappy all the time...it wouldn't be intermittent.

I'm also going to borescope and compression check it just to ensure everything looks good internally. No, I don't have a leak down tester on me, and yes, I know that would tell me a lot more, it might be time to get one.

If none of the above fixes pan out, I'm pretty much out of ideas.

Any thoughts, comments or inputs?

You have new injectors. Have you check that you got originals, not conterfeight ones? Its very common nowdays. Counterfeight Bosh injectors have been found even from stock of sertified Bosh service center. (somebody in supplychain have changed products from original boxes)

Long crank usually caused by missing pressure on fuel rail.

I’ve swapped injectors from one side to the other, and even taken my second new set for my other engine and swapped them. I buy all my Bosch injectors from FCP Euro. No change.

Prior to cranking, with the ignition in “on” but not cranking, the fuel rail pressure is 310kPa, immediately after cranking it jumps to 14970kPa (high idle immediately after start). Then it settles to 3260kPa for regular idle. I’m assuming this to be normal, but perhaps not?

Check this: https://www.jaguarforums.com/forum/x...15-xjr-283983/
Sorry. I don´t have info what the pressure supposed to be on 5.0 during the cranking or idle.
What octane rating fuel you are using? You mention VTT solenoids, so you must have normally aspirated version of 5.0 engine? NA engine have higher compresion rate than supercharged models. Therefore engine need min 91 Octane fuel, if i remember right. Because my memory can flick (and it does), please check the needed octane rating stated on sticker inside of fuel filler cover, if you havent went that trail already?

Thank you for the input! You
may be right about the injectors, but since I have misfires on all 4 cylinders, and I have both swapped injectors to the other side of the engine, and swapped new ones in, if the problem were an injector it would have moved with the swap, or gone away altogether when replaced.

as for octane, it’s always 93….unless I have to “settle” for 91 because that’s all that’s offered.

Yes please read the thread Vasara mentions as I went thru a similar set of problems. It was a VERY difficult 2-3 weeks while I went thru this because I was completely stumped.
I have posted pictures multiple times as this is so common.
Aaron another forum member also got burned by this and he had purchased the counterfeit injectors from FCP as you did! I think he did get his money back.

Any chance you can post a picture of the markings on the injectors you purchased?
Just to rule out a parts problem.
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Thanks for the advice, I’ll try and read the thread.

As for pics of the injectors, I think I have my second set laying around, I’ll see if I can take a few pics and send them out.

if this a bosch PCM please reset adaptations first and recheck.

they never fixed that particular truck, they checked lash and the buckets were all out of spec, new buckets to spec and the problem came back 2k miles later.

your problem usually happens because of mistiming under a tooth off which isn’t hard to do unfortunately. you need to rock the cam back and forth while tightening the locks until it stops

if you’ve reset adapts and your long terms are high negative on that bank it’s all leaning towards mistimed. i’d get a better set and retime it again, preload those phasers good.

Sorry for the delay, but crazy busy here.

https://cimg5.ibsrv.net/gimg/www.jag...7884790b4.jpeg
https://cimg1.ibsrv.net/gimg/www.jag...51054f75e.jpeg
https://cimg3.ibsrv.net/gimg/www.jag...19546f07b.jpeg

interestingly, aside from a few numbers….nothing really denotes these as “Bosch.” I should probably add, I don’t have any of the original injectors from my engines as I’ve since replaced them all. So unfortunately, I have nothing to compare them to, but I’ll look at your thread/pics.

as for the PCM, it’s the Denso version. I’ve reset my adaptations a couple times, and rechecked timing twice. Everything is dead on. As the the variator preload, I actually set it twice. Once the first time, then just to be sure when I opened it back up and double checked.

Crap, just checked your pics, and at least this set is legit….

lemme get my scope and see if I can see the ones on the truck.

Excellent information about counterfeit parts. Thanks all.
However, I did not see that an oscilloscope has been used to check timing and signal integrity that may include faulty connections and failing sensors.
Check out:

disable the bank 2 magnets and see if your misfire goes away. the usual half a tooth off symptoms are at 1000rpm when advance is commanded

when you say “disable the Bank 2 magnets” are you talking about the cam position sensors?

Also, I used my borescope to check out the injectors, and they all have the “H” symbol on them…so I’m going to assume they’re legit Bosch injectors.

vvt solenoid/magnet

you can push the phaser in with a screwdriver to manually advance

good info, plus it gives me a reason to go pick up an O-scope!

I’ll never say I’m 100% sure it’s still in time, except for the fact that the after e few seconds it idles and runs fine. It just seems to struggle to start when cold, and the. When it has be run for a while, then let sit for roughly an hour or two, it’s been struggling to start, catches, then dies. Then it restarts like nothing is wrong.

I can’t shake the feeling something is throwing the PCM off, it’s just driving me insane!

I’ll go give it a shot and see what happens.

do you recommend pulling the solenoid out, or just disconnecting it?

disconnect is all you need. if needed you can pull them out and safely actuate it yourself for diagnostic purposes.

Bosch owns Hella now so no the injectors won't have anything that says Bosch on them. Just that stylized H symbol.
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Ok folks, sorry for the delayed responses, I’ve been crazy busy, but had some time this morning to go over a few things.

first, I swapped the plugs, just to be certain/safe. No real change.

-When the plugs were out, I scoped all 8 cylinders, and aside from a little carbon here and there, they all appeared to be in great shape. Especially considering the 210K on the odometer.

-I ran compressions for all 8 as well and got the following:

1. 212
2. 197.5
3. 205
4. 199
5. 192
6. 197
7. 205
8. 207.5

not quite as tight a spread as I’d like, but good enough…except for cylinder 5…that one’s a little off, but I’m going to chock it up to dirty valves.

I did smoke check it again and discovered two spots along the air intake track that were leaking and I sealed those. (Stupid rover hose clamps)

finally, I noticed something. The car struggles to start, not when it’s hot or cold, but when it’s in between. Basically, we drive it tonight, parked it for 2 hours, and then it struggled to start and threw the error codes. I cleared the codes and it started back up perfectly.

sooo….im beginning to think its timing related…it could still be a oddly malfunctioning injector, but I don’t believe it is.

I’ll try unplugging the magnets tomorrow and see what happens.

thanks again for all the extra ideas!!