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Z22YH What is broken Fuel Regulator or Fuel Pump ???

Discussion in 'Engine Queries' started by mikady, August 30, 2013.

  1. I really hope someone can help me. My Zafira 2.2 (Z22YH Enginge) Petrol went into limp mode and the amber spanner light came on. The RAC diagnosed a code P1191 Low Pressure Fuel input Sensor. My local garage have had it for 3 days now and still have not been able to diagnose the problem. When I called in to check on progress the Exhaust Emission light had come on and the garage told me it is misfiring on cyclinder 3. They are not sure what the problem is.

    I had fitted in 2009 a new Siemens Fuel Pump and Vauxhall have told me that via a silent recall my Zafira had a new fuel pressure regulator fitted in 2010 it has a white spot on it not sure what that means and the last five digits on the the regulator is 338 09. I also had a new fuel filter fitted in 2009. The Swirl Valves have also been repaired and new timing chain fitted.

    From reading this forum and others I guess it's the Fuel Regulator or Fuel Pump. Here is my question how can the garage tell if it is the regulator or pump. If it is low pressure does that mean the regulator? If the pump failed would the car go into Limp Mode. I don't want to spend money on something that is not broken.

    Can anyone suggest what the problem is Vauxhall have informed me that a new regulator would be £110 plus VAT.

    Any help is much appreciated.

    Thank you.
    #1 mikady, August 30, 2013
    Last edited by a moderator: August 30, 2013
  2. Evocarlos I have read that thread and posted on it also but no on has responded. I was wanting a clear direction on what is broken. Is it the regulator or the pump? I need a clear diagnosis.
  3. the info for testing the hp pump is in post #2 in that link that would verify if the hp pump or low pressure (tank pump) was shafted
    i dont have a z22yh so cant best advice
    but its down to a process of elimination get the pump checked then if fine move on

    (2005.06) - Signum 2003 To 2004 - Engine Type: Z22YH - High Pressure Pump, Fuel Pressure Regulator - Defective (P1191 set)

    Signum/Vectra 2003 To 2005 - Engine Type: Z22YH

    High Pressure Pump, Fuel Pressure Regulator - Defective (P1191 set)

    The customer complains that the MIL is on. P1191 us set in the ECU.

    1. High pressure pump defective, vehicle not driveable

    2. Fuel pressure regulator defective, vehicle runs in emergency operating mode

    This is caused by a defective high pressure pump or fuel pressure regulator valve. In case of customer complaint proceed as follows to verify the defective part:

    1. Check fuel feed pressure at high-pressure pump with manometer (engine running)
    Is primary feed pressure less than 3, 4 bar?

    Yes: Low pressure fuel feed failure -> check fuse, relay, intank module.(tank pump)
    if its not low pressure move on

    hp pump
    2. Measure fuel pressure in the high pressure rail at idle by using Tech2 Datalist.

    Is fuel pressure in the high pressure rail less than 600kPa?

    Yes: High pressure pump defect, replace.

    pressure regulator
    3. Pull off connector (two-core) of the fuel pressure regulator.

    Measure the voltage of the fuel pressure sensor at 3000RPM (standing vehicle) with Tech2.

    Is Voltage greater than 1, 2V?

    Yes: Fuel pressure regulator defect, replace.

    4. Defect is not clearly allocable to one component. Proceed according to TIS 2000 service instruction.
    • Like Like x 1
  4. You say you had a new Siemans pump fitted? These are the old pumps and cant be got from VX anymore. VX stopped fitting them as its this pump that fails no matter if its original or later fitted, the replacement pump is the continental pump. I'm no expert in the technical front but just from the shear amount of Z22YH threads ive read on the vec C forum I'd say its the pump especially as you also mention a misfire.

    A failing pump should get you to about 3000 rpm then put you into limp mode, or if you flaw it.
    • Like Like x 1
  5. Hi and thanks for the replies to date.

    I went to the garage today to find the car was running fine. It was not in Limp mode and no lights were on the dashboard. The engine was running fine and the garage have not done anything to it. They think it may be a sensor but they are not sure. Can anyone please advise I now have a car that is unreliable. My main worry is that it goes back into limp mode. I was going to buy a new fuel pump but the garage said I might buy it and it may not make a difference. Can anyone shed any light on this.

    Could it have been dirty fuel, could it have rectified itself?

    Any help is appreciated.
  6. Go and give it some beans, put the engine under load up to 4k and see how it goes.
  7. Rushy

    Thanks for your reply. I have revved it up to 5K and it seems and driven it at 3.5k and it is fine. What will putting the engine under load do?
  8. It will rev up to 5k fine even with a duff HP pump. You need to be doing it in gear and driving ( under load). If your just reving it then it doesn't need the same amount of fuel as its easy for it so the pump isn't being stressed.
  9. Hi Rushy,

    Thanks for the info. I will try in the morning and post the result. The garage think that because the fault code states the word input (Low Pressure Fuel Input) it means it is an electrical fault or the sensor is faulty. They are not sure how it has come out of limp mode and running fine now. I think it is the pump but if the pump was broken then it would not drive normally would it?
    • Old Old x 1
  10. Rushy did what you suggested and drove the zafira upto 5000rpm it stuttered and went into limp mode. Cannot yet provide the code but suspect it will be p1191 as spanner light came on. Do you think it's the fuel pump?

    Thank you.
  11. I'm no expert but that is exactly how mine used to behave. If I accelerated hard would get a noticeable lurch then car and spanner light would come on and get a p1191 code and a missfire code. After a few days light would go off. And it turned out to be the pump for me.
    Hope you get it sorted mate it brings back horrid memories for me.
  12. Jordy thanks for your reply.

    I am very tempted just to buy a continental fuel pump for £280, but if it is not that then I am back to square 1 and £280 out of pocket. Just out of curiosity did you need put it on a tech 2 machine once the pump had been fitted? or did the engine just rectify itself? The garage think it may be a sensor I am no expert but my money is on the pump.
  13. No just fit the pump and away you go so easy to do as well took about 15mins. I don't know what sensor it could be as far as I can remember when I was looking into it if you have a p1191 code its either pump or regulator and that's it. I know what you mean tho its a bit scary to fork out nearly £300 and it don't fix it.

    Another thing I just remembered I read twice elsewhere on the web that the full code is important. If it is 119152 which mine was then its apparently the pump. I don't know if that's true or why but like I said I've read it twice. Try doing the pedal test and see what the full code is.
  14. It is a bit of a dilemma as you say, there never seams to be a full on pin point fault code.
  15. Jordy

    The full code from the OP COM is P1191-52 then we cleared it. Then it showed P1191-5a fuel sensor low input.
  16. Hi I know this is now an oldish thread but have a zafira b and had my car go into limp home mode this afternoon code on dash says 1191-5A and after reading several posts know its either going to be the pump or reg, has anyone had the same code as mine and has fixed it? Thanks in advanced for any help
  17. Hi Andy

    I had this problem and it was the fuel pump the one located in the engine compartment. I replaced the siemens fuel pump with a continental one as the Siemens pumps are defective. I bought it off ebay for a fraction of the price the main dealer was charging. It is a straight forward job that can be completed in 20 mins. Since then the car has been fine.
    • Like Like x 1
  18. Hi thanks for the response was kind of thinking that it might be the pump after trawling through quite a few thread on net, will price one up in morning and get it sorted many thanks again, will post again after sorting car out.
  19. Hi have you tried Autovaux £216 brand new :) Dont get one off ebay with no come backs!!
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