I had one over 3 years ago. Same year Qx56 from the auction. Engine died when you applied throttle, checked live data high pressure and low pressure were about the same. Checked HPFP and found that the cam bucket was stuck in the bore and had a hole in it. Prescribed T-Chain job. What a massive job?! My first t-chain job ever. Discovered that the cam lobe for pump wore out and crank gears lost some teeth that somehow were just laying on crevices of the front cover, but no further damage to engine. The front cover had to be replaced as it houses the HPFP and the bore wa damaged by the bucket
Nice diag, Jake! Sweet Autel too! Personally I like to have the scope and scanner as 2 separate tools, so you can use both of them simultaneously...2 screens is better than one! :)
The Ultra has the ability to split screens, therefore should see two things at once. I own the MS919 which is basiclly a lil ultra, my only regret from buying the 919 is not buying the ultra for it's abillity to split screens, for example bi-directionaly commandind something to operate and watching it on the scope at the same time. Im sure Jake will have a video coming soon on that awsome tool. Great Diag Jake!
@@autodiagyt I'd like to see you really test it to the limits.. Because a lot of times they don't really have enough compute power to do everything you need.. For example.. running several live data pids on the scanner side.. while running all 4 channels on the scope side.. and then trying to screen capture it all. Most of the tablets that they choose to use won't have enough power to do all that at once. So you are still limited vs having separate units. But I do get that it's more convenient to have them both built into one
I know fault codes aren't always straight lines to issues. But wouldn't it have low fuel pressure faults on the original pump? (anyone worth their salt would likely have seen the damage on that pump/bucket drive when replacing it). Open circuit code I can comprehend if it's not seeing a pressure reflecting what it's asking for. But how does it set a fuel pressure high from a new pump and mechanical damage?
Ouch!! 1500 for a part that didn't fix the problem, that's gotta sting. People will never learn to get a guaranteed diagnosis, and not go to a parts changer and throw money away.
You have to remove the intake just to replace the starter, same with the toyota v8s... Anytime you break a seal you must replace the seal due to hot and cold cycling, water moisture, dirt...
Just wanted to follow up with you....I know you never fixed the car because they decided to send it to auction but the qx80 I had here....we took it apart and yep the fuel pump lobe was off time. You saved the day!
Where are you located? And approximately how much is this repair? I have a 2012 qx56 with the same problem. When I removed the HPFP, the lifter bucket was actually fused in place & a hole was worn completely through the bottom. I was able to remove the damaged bucket with a tapping hammer & put in a new one. But of course the check engine light is still on, and I know it’s going to need a cam lobe/timing repair.
@@autodiagyt Thank you for the reply. I understand your logic. I am used to 300 to 600 psi at idle depending on manufacturer. Wha is normal idle pressure on that model? Thank you in advance for your answer.
Man Jake I'm chasing a P0087 fuel rail pressure low issue on a Honda Vezel hybrid. It's intermittently cutting out. But when it cuts out, it starts up after a few hours. Great tips
Very clear minded diagnostic, Jake! That's what allowed to think your way to the carnage inside. Too bad there is no timing information for the pump but, once diagnosed, it will be straightforward to repair. Great job!
Great find again, with it setting a circuit code most people would be obsessed with tracing wiring or looking at the ECU being the issue but outside the box thinking you found it well done
@@autodiagyt If you apply power to the pump valve at 14:24 directly from the battery, won't that burn the valve coil? not better with an additional resistor or bulb. Can all valves be powered this way?
@@ebolti22 you need to be mindful of what you are doing and know the limits of the device. It’s a coil of wire and it’s got a workable duty cycle at different voltages. Lower voltage longer duty cycle, higher voltage shorter duty cycle. So yes in this case it’s not an issue to give it full battery power as long as you are not just holding the power to it. Quick testing is fine on it because that’s what the ecm is doing.
What brand of pierce probes do u prefer? Sorry to bother u with a simple queation but as much as u use them u will have a way better idea of what i should get. Cuz what i got now are very frustrating to use
Good diag. Those little lifters are known of braking and causing damages to the timing cover. I think that little damage that you referred to on that locking plate is from a previously damaged lifter. Maybe the stuff inside also. Who knows.
High duty cycle/on time shows an attempt by the pcm to reduce fuel pressure. I'll also bet the lobe shifted position. A worn lobe shouldn't cause high pressure. I'd love to see the camshaft to verify this. Great video too!!!
@@autodiagyt I'm still having trouble believing worn lobes causing high pressure and jumped timing, I really need to see that with my own eyes. I've done a lot of chains over the years and watched a lot videos and this is the first time I've heard of this so before I tell a customer a jumped timing chain is causing high pressure I want to see a confirmed fix first. I know lobes and buckets are a problem for wearing out but high pressure? I don't know, I want to see it.
@@ws2664 so the pressure pulse is timed with an injection spraying. So if the pump is compressing with the injectors closed there is your increased pressure.
Of topic, on your 2005 Honda element video did you try disconnecting the after cat o2 sensor and watch the trims? I have experienced that on Toyotas around the same year range.
Yes I believe I did but I can’t remember if it had any effect at all. I remember I replaced one O2 but can’t remember which one just to make sure it was reading correctly.
@@autodiagyt Thank you for the reply. The way I test O2 sensors for proper operation is to match lambda scan data with tail pipe lambda reading using a gas analyzer. I am a retired automotive technology teacher, always kept a part time job diagnosing problem vehicles, your videos and your methods are very good.
I have a question slightly unrelated to this video. In your earlier videos you show many short circuits, how to find an incomplete short circuit, a "soft" short circuit to ground in a low-current circuit?
I use a scope for intermittent circuit issues so I can see what happens. I have an old video on a dodge ram with a very intermittent transmission fault that shows it found with the scope.
@@autodiagyt I was more interested in how to find a partial short circuit, a large resistance, where a current of only 300 mA flowing through a small test tube does not actually light the bulb, making it much more difficult to trace,
@@ebolti22 oh that wouldn’t be a short. That is just high resistance in the circuit. In those cases I work the circuit backwards to the source and find where the power is correct.
I had one in my shop with the same issue. They put a new pump and broke the feed line. I pulled the pump and the bucket was completely worn and the cam lobe was just as bad. I recommend a motor due to metal being in the motor.
Regarding measuring if it is in time or not... Can you do it by connecting scope to high pressure sensor signal output, and one of the injectors? I would expect the pressure peak just before injector trigger. Am I missing something?
Mostly been listening to the 90s. Started with some counting crows, that lead to blues travelers turned into some sister hazel and barenaked ladies then I heard the crash test dummies for the first time since 94. Now we're getting into the female artist side side of the 90z.
We are fighting this issue now after changing all the timing components incl that HPFP cam lobe. The pump is new as well. Everything appears timed and we don't have timing codes. Where else should we look? Even put a new PCM in it thinking it was the culprit not able to control the pressure. Our symptoms are the same - maxed out pressure 2600+ and same codes plus P0193. The original issue was low pressure due the cam lobe wearing thru the lifter bucket - common issue - so we replaced all that and the pump too....now this.
I had one over 3 years ago. Same year Qx56 from the auction. Engine died when you applied throttle, checked live data high pressure and low pressure were about the same. Checked HPFP and found that the cam bucket was stuck in the bore and had a hole in it. Prescribed T-Chain job. What a massive job?! My first t-chain job ever. Discovered that the cam lobe for pump wore out and crank gears lost some teeth that somehow were just laying on crevices of the front cover, but no further damage to engine. The front cover had to be replaced as it houses the HPFP and the bore wa damaged by the bucket
The problem was permanently fixed right?
Yup ohc style engines are a pita
why would it need a timing for hpfp? isnt it that cam and crankshaft position sensor is enough?
Great question and there will be another video coming in a couple days on this same vehicle and this question will be answered.
Nice diag, Jake! Sweet Autel too! Personally I like to have the scope and scanner as 2 separate tools, so you can use both of them simultaneously...2 screens is better than one! :)
But wait till my next Ultra video!
The Ultra has the ability to split screens, therefore should see two things at once. I own the MS919 which is basiclly a lil ultra, my only regret from buying the 919 is not buying the ultra for it's abillity to split screens, for example bi-directionaly commandind something to operate and watching it on the scope at the same time. Im sure Jake will have a video coming soon on that awsome tool. Great Diag Jake!
@@autodiagyt I'd like to see you really test it to the limits.. Because a lot of times they don't really have enough compute power to do everything you need.. For example.. running several live data pids on the scanner side.. while running all 4 channels on the scope side.. and then trying to screen capture it all. Most of the tablets that they choose to use won't have enough power to do all that at once. So you are still limited vs having separate units. But I do get that it's more convenient to have them both built into one
Why did I read this with your voice in my heard 😳
You are everywhere, Ivan.
Hello, what's the specifications of the diagnostic tool. Plz🙏
I’m not sure what you mean. The scantool is the Autel Maxisys Ultra
Just bought the Ultra myself! so glad to be watching you use it as well as your other great tools
I know fault codes aren't always straight lines to issues. But wouldn't it have low fuel pressure faults on the original pump? (anyone worth their salt would likely have seen the damage on that pump/bucket drive when replacing it).
Open circuit code I can comprehend if it's not seeing a pressure reflecting what it's asking for. But how does it set a fuel pressure high from a new pump and mechanical damage?
Ouch!! 1500 for a part that didn't fix the problem, that's gotta sting. People will never learn to get a guaranteed diagnosis, and not go to a parts changer and throw money away.
Thank you for taking us along and showing us. 👍
You hit it outta’ the park with this great find !! Nice 👍🏼 one .
Thanks for sharing your knowledge and skill .
👊🏼 🔥 💻 📈 🧰
Seems you're developing a liking for Nissans now. 😂
Definitely not lol
@@autodiagyt 😆😆😆👍.
This is the most common problem with nissan
thanks for showing me some thing totally new again.ck,wisc.
You have to remove the intake just to replace the starter, same with the toyota v8s... Anytime you break a seal you must replace the seal due to hot and cold cycling, water moisture, dirt...
BTW, go to the scope setting and change to save last used setting. Thank me later 😊
Just wanted to follow up with you....I know you never fixed the car because they decided to send it to auction but the qx80 I had here....we took it apart and yep the fuel pump lobe was off time. You saved the day!
There is TSBs about these timing chains and some even had a extended warranty covering them.
It's will be easy if removed the high pressure pump and check the cam and the lifter
Oh. Nm. It has a separate system. Nevertheless that's where my mind went. Let's see.
Where are you located? And approximately how much is this repair? I have a 2012 qx56 with the same problem. When I removed the HPFP, the lifter bucket was actually fused in place & a hole was worn completely through the bottom. I was able to remove the damaged bucket with a tapping hammer & put in a new one. But of course the check engine light is still on, and I know it’s going to need a cam lobe/timing repair.
I'm in North Alabama but I don't do these repairs.
Excellent video. Was the code intermittent or did it set right away every time? Was the high pressure at idle a clue?
Basically right away. You would have to crank the engine and it would set within seconds
@@autodiagyt Thank you for the reply. I understand your logic. I am used to 300 to 600 psi at idle depending on manufacturer. Wha is normal idle pressure on that model?
Thank you in advance for your answer.
Man Jake I'm chasing a P0087 fuel rail pressure low issue on a Honda Vezel hybrid. It's intermittently cutting out. But when it cuts out, it starts up after a few hours. Great tips
This very common in nissan you should replace the hpfp cap every 70k
Just replace everything every time you do a timing belt/chain change.. It's not just the cap.. The cam lobe goes bad too.
Fantastic found Jake.glad you keep sharing your knowledge with us.
Yeah !
Very clear minded diagnostic, Jake! That's what allowed to think your way to the carnage inside. Too bad there is no timing information for the pump but, once diagnosed, it will be straightforward to repair. Great job!
Strange how that happens and fools us sometimes. See it all the time on the GM 2.4.
Great find again, with it setting a circuit code most people would be obsessed with tracing wiring or looking at the ECU being the issue but outside the box thinking you found it well done
Yeah it sets a circuit fault because the pressure isn't reacting as expected when commanding the valve.
@@autodiagyt Key point. Thank you.
@@autodiagyt If you apply power to the pump valve at 14:24 directly from the battery, won't that burn the valve coil? not better with an additional resistor or bulb. Can all valves be powered this way?
@@ebolti22 you need to be mindful of what you are doing and know the limits of the device. It’s a coil of wire and it’s got a workable duty cycle at different voltages. Lower voltage longer duty cycle, higher voltage shorter duty cycle. So yes in this case it’s not an issue to give it full battery power as long as you are not just holding the power to it. Quick testing is fine on it because that’s what the ecm is doing.
The Ultra scope module has a waveform generator and an actuator driver. You make the waveform and can duty cycle the solenoid with it.
The cam lobe of the high pressure pump.
What brand of pierce probes do u prefer? Sorry to bother u with a simple queation but as much as u use them u will have a way better idea of what i should get. Cuz what i got now are very frustrating to use
The ones I use are from aeswave.com
I hate Nissan/Infiniti
IF you remove the fuel pump ... can you see the damaged lobe in the housing?
If you pull out the lifter bucket also.
That looks serious..
Good diag. Those little lifters are known of braking and causing damages to the timing cover. I think that little damage that you referred to on that locking plate is from a previously damaged lifter. Maybe the stuff inside also. Who knows.
Great diagnostics!!
High duty cycle/on time shows an attempt by the pcm to reduce fuel pressure. I'll also bet the lobe shifted position. A worn lobe shouldn't cause high pressure. I'd love to see the camshaft to verify this. Great video too!!!
Oh it's definitely out of time.
Yea I'm having a hard time myself in believing that.
@@ws2664 in believing what exactly?
@@autodiagyt I'm still having trouble believing worn lobes causing high pressure and jumped timing, I really need to see that with my own eyes. I've done a lot of chains over the years and watched a lot videos and this is the first time I've heard of this so before I tell a customer a jumped timing chain is causing high pressure I want to see a confirmed fix first. I know lobes and buckets are a problem for wearing out but high pressure? I don't know, I want to see it.
@@ws2664 so the pressure pulse is timed with an injection spraying. So if the pump is compressing with the injectors closed there is your increased pressure.
very interesting case
Of topic, on your 2005 Honda element video did you try disconnecting the after cat o2 sensor and watch the trims?
I have experienced that on Toyotas around the same year range.
Yes I believe I did but I can’t remember if it had any effect at all. I remember I replaced one O2 but can’t remember which one just to make sure it was reading correctly.
@@autodiagyt Thank you for the reply.
The way I test O2 sensors for proper operation is to match lambda scan data with tail pipe lambda reading using a gas analyzer.
I am a retired automotive technology teacher, always kept a part time job diagnosing problem vehicles, your videos and your methods are very good.
I have a question slightly unrelated to this video. In your earlier videos you show many short circuits, how to find an incomplete short circuit, a "soft" short circuit to ground in a low-current circuit?
I use a scope for intermittent circuit issues so I can see what happens. I have an old video on a dodge ram with a very intermittent transmission fault that shows it found with the scope.
@@autodiagyt I was more interested in how to find a partial short circuit, a large resistance, where a current of only 300 mA flowing through a small test tube does not actually light the bulb, making it much more difficult to trace,
@@ebolti22 oh that wouldn’t be a short. That is just high resistance in the circuit. In those cases I work the circuit backwards to the source and find where the power is correct.
Is there like a reason why it would make too much pressure
Yes the timing of the pump actuation in relation to injector firing.
Autel is better than topdon in my opinion but it’s only an opinion
They each have their pros and cons.
Hi thanks for sharing but I didn't understand why it caused high pressure if you can explain thanks
The pump is out of time. Hopefully I will have another video on this same vehicle coming out later next week going more in depth about it.
thanks
sounds rough was that cam lobe noisy
High pressure pumps usually are noisy when running max pressure but yeah the extra pressure on the lobe probably was making part of it also.
👍
Nice find! thanks for sharing as always.
Great job jake
Well done 👍
Nice find
I had one in my shop with the same issue. They put a new pump and broke the feed line. I pulled the pump and the bucket was completely worn and the cam lobe was just as bad. I recommend a motor due to metal being in the motor.
Exellent. 👌
Thank you! It showed me you read the posts from your videos. Well done and great catch on this one.
Just found this channel recently, so helpful as someone just getting into this stuff. Thanks
I change everything on the timing component
Regarding measuring if it is in time or not... Can you do it by connecting scope to high pressure sensor signal output, and one of the injectors? I would expect the pressure peak just before injector trigger. Am I missing something?
I linked a video where Scott shows the ADDi and I think he covers that in it.
That’s a good one, I am blown away how fast you find that fault. What cause you think of timing? Am impressed!!
It’s just known the mechanics of the system
Thanks for this wonderful video
Wow great find Jake thanks for sharing amigo
Very good explenation and information..
Clear nail polish works better then liquid electrical tape, looks better, and drys way faster
I've used clear nail polish and it does work good but I've seen it after a few years get flaky. That's the only reason I' now used liquid tape.
Thanks , dang good video 😊
"Broke my heart in the trailer park"
lol yeah the guys next door play the music loud and it makes videos harder to do 😣
@@autodiagyt I play all day in my shop but not loud! Keeps me at ease!
@@joesmo4749
Me too . Johnny Cash or Stan Rogers or Bruce Springsteen or Hank Williams Jr. kinda stuff .
Mostly been listening to the 90s. Started with some counting crows, that lead to blues travelers turned into some sister hazel and barenaked ladies then I heard the crash test dummies for the first time since 94. Now we're getting into the female artist side side of the 90z.
@@joesmo4749 I don’t mind the music but it makes recording videos harder because I can get copyright issues flagged.
Great video❤
wouldn't a worn out lobe cause low fuel pressure?
Yes but if it's also out of time then you can have increased pressure even though the lobe is worn.
Grasias
❤❤❤❤❤❤❤❤❤
We are fighting this issue now after changing all the timing components incl that HPFP cam lobe. The pump is new as well. Everything appears timed and we don't have timing codes. Where else should we look? Even put a new PCM in it thinking it was the culprit not able to control the pressure. Our symptoms are the same - maxed out pressure 2600+ and same codes plus P0193. The original issue was low pressure due the cam lobe wearing thru the lifter bucket - common issue - so we replaced all that and the pump too....now this.
I have to replace my cam lobe. Did you have to remove the whole front end to replace the cam lobe?
I don’t know what the p0193 code is but check out the video after this one where I get more in depth about why the pressure was high.
Yep I did the same jop before nobody has these parts only dealer
I have to replace my cam lobe. Did you have to remove the whole front end to replace the cam lobe?