P1191 Opel Vectra Z22YH engine

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Re: P1191 Opel Vectra Z22YH engine

Postby Tronic » Tue Nov 29, 2016 10:13 am

Hi Andrew!

Well done and thank you! That's what I where thinking about too. I don't know to what degree it is possible to safely point out faulty pistons/diaphragm by looking at the fluctuations in the rail. I will have to investigate that further when this Opel Vectra gets back to our workshop, but best would be if I found a working one. All these thoughts came out gradually by looking at the saved psdata files and you Andrew took it one step further by using the 120deg rulers since it is a 3 piston pump. I don't know, we could be wrong, but it is very interesting to see if it could be used somehow. :D Lets see what others have say about this, hopefully they don't use an axe to cut it down to fire wood :lol:

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Re: P1191 Opel Vectra Z22YH engine

Postby Technician » Tue Nov 29, 2016 10:57 am

I would suspect the manufacturer of the pump will have voltage ranges to compare your readings to, by example, BMW DDE version 4.0 diesel HPP's have a 40/40 voltage range when using a scope, anything outside those upper and lower limits suggests a fault present.
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Re: P1191 Opel Vectra Z22YH engine

Postby Tronic » Tue Nov 29, 2016 4:16 pm

Hi Technician and thanks for interesting information!

Just because of curiosity I will drop Continental a mail asking for a data sheet for this particular pump. Do you have any scope traces saved for this measurements?

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Re: P1191 Opel Vectra Z22YH engine

Postby Tronic » Tue Nov 29, 2016 5:25 pm

Well, had to take another look at the two frames - link in page 4 post 28 if you want to have a look - I saved and compared the pressure peaks - fluctuations in the rail - from frame 8 and 9. Look at this picture and see yourself: https://mega.nz/#!kF9iHCbL!dK5t-SZmvi7A ... X5eFCA6oY0

I am not sure, but to me it seems like one of the three pistons/diaphragms - 120deg for each peak - at 240deg does its job really bad. Please correct me if I am wrong... :oops:

Sincerely :)

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Re: P1191 Opel Vectra Z22YH engine

Postby STC » Tue Nov 29, 2016 8:18 pm

Bjorn

It does look as though Andrew has hit the nail on the head and you have a faulty HP pump diaphragm.
But looking at the captures your LP supply is just as erratic, with some similar regularity more so when demand is increased.
The question now would be: Which one is the Cause and which is the Effect ?

I think it will be a case of getting the car back and get both pumps (one at a time) working under load to see which one , if any, falls down.
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Re: P1191 Opel Vectra Z22YH engine

Postby Technician » Tue Nov 29, 2016 10:58 pm

Tronic wrote:Well, had to take another look at the two frames - link in page 4 post 28 if you want to have a look - I saved and compared the pressure peaks - fluctuations in the rail - from frame 8 and 9. Look at this picture and see yourself: https://mega.nz/#!kF9iHCbL!dK5t-SZmvi7A ... X5eFCA6oY0

I am not sure, but to me it seems like one of the three pistons/diaphragms - 120deg for each peak - at 240deg does its job really bad. Please correct me if I am wrong... :oops:

Sincerely :)

Bjorn


Tronic wrote:Well, had to take another look at the two frames - link in page 4 post 28 if you want to have a look - I saved and compared the pressure peaks - fluctuations in the rail - from frame 8 and 9. Look at this picture and see yourself: https://mega.nz/#!kF9iHCbL!dK5t-SZmvi7A ... X5eFCA6oY0

I am not sure, but to me it seems like one of the three pistons/diaphragms - 120deg for each peak - at 240deg does its job really bad. Please correct me if I am wrong... :oops:

Sincerely :)

Bjorn


Hi Bjorn,

The data I have is not technically for your HPP, however visualising your voltages in the above scope illustration and the ones I have, they are similar, but the voltage range is not the same.

Notes from my data;

You need to know what the maximum permissible value for the amplitude is, and you need to know what a good signal should pulsate at, the pulsations represent the pressure waves created by the three pistons in the HPP, one revolution of the HPP equates to 3 pulses, and the pulsations will increase, therefore look for regular pulses.

Lets just say as an example the HPP should have a maximum of 40mv amplitude, then the pulsations should be regular at say 25 ms, three pulses would be 3 pistons in the HPP, which would just keep repeating as the HPP runs, so you would need to know the speed of the pump, the time and observe 3 pulsations are present in that 360 degrees and time period. :wink:

Whatever in your HPP the amplitude should be, i.e in my example 40mv, the voltage must not exceed that value, if the voltage is greater then that does not automatically say the HPP is faulty, it could be a weak membrane in the rail pressure sensor, also as STC said, you must ensure that the LP side fuel supply pressure/volume is correct, an increased voltage signal from the HPP shown on the scope can also be caused by low side fuel pressure, so the scope voltage is not conclusive on its own.

Just a few general notes to help if I can, but not specific to GDI set up;

Ensure that the fuel tank is at least 1/4 full.
Check the pre-supply pressure with a gauge.
Check the return flow/pressure to the tank.
Road test the car with the gauge installed and ensure that the pressure is not dropping off.
Make sure that the fuel supply before and after the fuel filter don't differentiate more than 0.3 bar
Make sure the pre-supply volume/pressure is OK.
Check for internal injector leakage.
Check pressure regulator (internal leak)
Check the HP system is both internally and externally leak free.
Does the vehicle manufacturer recommend a set point rail pressure?
Have you checked to see if a control flow valve is fitted to the HPP?

Thanks

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Re: P1191 Opel Vectra Z22YH engine

Postby andrewbishop66 » Wed Nov 30, 2016 12:12 am

Hi all

My quick down and dirty method is independent pressurised fuel supply (converted ac flush system which can deliver fuel from 20 psi to 100 psi if needed ) rules one out or in

Andrew
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Re: P1191 Opel Vectra Z22YH engine

Postby Tronic » Wed Nov 30, 2016 1:25 am

STC

It does look as though Andrew has hit the nail on the head and you have a faulty HP pump diaphragm
.

Most probably, yes. I pointed out these fluctuations, both LP & HP side, in an earlier post, but at that time there was no one that had anything to say or reason may have been that it wasn't seen as relevant findings. It ended up with no more posts, since I didn't want to pollute the forum with fantasies or dangerous imaginations. Then, by PM between other forum members - thanks to Technician and Andrew - instead of posting at the forum and in an early stage, it came clear that the fluctuations, in our communication by PM, where not normal and most probably stemmed from the HPP. However, after a couple of searches on Google it stood clear that this particular pump has three pistons/diaphragms and then we knew how it worked and in a more confident way, know what to look for. I am not fully convinced yet if these findings are de facto what we believe it is. That being said...

Thanks to the forum members I am on my way to solve this issue, or at least small part of it, by using saved psdata files and of course, lots of thinking and help from you folks. Of course that include all the great helping text contributed with hints on "how to's" and other advices. I would like to say big thanks to this excellent forum and also that I am glad to be a member.

Please let me do some thinking even though it may be seen as pure guesses or fantasies. I am here to learn and get help when needed, as probably all of you once in a while want, and when I can, I will gladly share with you my experiences and from my skills in electronics. As many of you professionals know a lot more than I do, why don't take the opportunity to write freely from heart and tell me that I am wrong or right and of course why - in a polite way... Yes, I know I shouldn't discuss this before I get the Opel in our workshop, but as the frames are saved and open to see for everyone it is possible to, in the mean time until I have the car, continue musing. Administrators, feel free to tell me if there is too much irrelevant text or if you so wish, just clean it up.

I think it will be a case of getting the car back and get both pumps (one at a time) working under load to see which one , if any, falls down.


STC, absolutely I will do so, thanks!

But looking at the captures your LP supply is just as erratic, with some similar regularity more so when demand is increased.


Yes that is thru! It seems like there is also a pressure rise on LP side when demand decreases. That can be seen especially at the rail pressure peak in frame 9. Could that be partly because of higher charge voltage and thus more fuel delivery from LPP? As seen in frame 8 at the end of pressure demand the peak LP pressure decay slowly as the engine rev down, not much though.

Sorry for asking lots of questions but I assure you, that all I want is to learn how things work...
Feel free to just read and wait until our Opel gets back to our workshop.

I'll be back then...

Sincerely

Bjorn
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Re: P1191 Opel Vectra Z22YH engine

Postby andrewbishop66 » Wed Dec 07, 2016 12:26 am

Any more data yet Bjorn

I have planed to do some tests on one of my daughters cars over christmas they both have vw with fsi engines I know the sensors and the regulator are easy to get to
Going to restrict lp flow and monitor hp sensor just to see the affect
this hp pump is different but id like to see what effect reducing lp has on the hp sensor I think STC raises a good point

I keep looking out for a vauxhall to test but only seem to get diesels at the moment

Thanks Andrew
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Re: P1191 Opel Vectra Z22YH engine

Postby STC » Wed Dec 07, 2016 2:18 am

Andrew

There is no big difference in LP & HP Pressure Generation Principles between GDi & Diesel. (You wont need me to point out the massive HP pressure differences)

Neither will the Vauxhall GDi be fundamentally different from the VAG FSI.

Going to restrict lp flow and monitor hp sensor just to see the affect
this hp pump is different but id like to see what effect reducing lp has on the hp sensor


Restricting LP flow will have a very different effect to a faulty in tank pump LP pump pumping erratically (if that is the fault on the Vectra - we do not know that yet)

There may not be a Direct & Immediate relationship between LP & HP due to the many components and failure strategies involved.

First you will need to acknowledge the Existence of a Fuel Pressure Regulator, Fuel Quantity Control Valve ( i.e. Bosch HDP2) Demand Controlled In Tank Supply Pump, LP Pressure Sensor. (some or all the above will be fitted)

As you restrict the LP side I would guess many things can or will happen to maintain correct HP as long as it possibly can.

The LP pressure sensor will see an increase or decrease dependant on which side of it you strangle the supply, Quite likely the In tank Demand Controlled Pump will be turned up or down - again dependant on where you strangle it.

The HP side will see a decrease in pressure and open up the Fuel Quantity Control Valve (IMV) and or the Fuel Pressure Regulator desperate to maintain pressure. Further more, as it struggles to maintain pressure you should see O2's go flat lean and Injector Durations opening as It begs for fuel.

You will need to be looking at approx 10 different PID's graphed on a scantool and it should paint a real good picture that has both diagnostic & educational value. Then an insight into its keep alive strategy.
Your Verus would be ideal for capturing that info, if you post the file I have Shopstream to view it.

PS. Your daughters will not thank you for running the HP pumps dry :o :o (about £200 a pop and a common failure should you be interested)
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