As an extra to that the idle is a bit rough with the revs going up and down slightly even after the cam sensor being replaced. Just before all of this i had the water pump and thermostat replaced and the radiator was taken out to do this. thanks
error code
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sapper1592
- Joined: Tue 06 Jul, 2010 15:53
- Posts: 58
- Location: Hull
error code
I have had my 2000 ,1.8 in for check engine light and it had 2 faults showing,one was the cam sensor which has been replaced the second has stumped my friend who owns the garage and it is FUEL PRESSURE LOW TO B+. He has called Bosch who supplied his kit and they are not able to help.The check engine light has not come back on so dont know if the cam sensor change will have sorted it .Has anyone had similar or know what it might relate to. Many thanks
As an extra to that the idle is a bit rough with the revs going up and down slightly even after the cam sensor being replaced. Just before all of this i had the water pump and thermostat replaced and the radiator was taken out to do this. thanks
As an extra to that the idle is a bit rough with the revs going up and down slightly even after the cam sensor being replaced. Just before all of this i had the water pump and thermostat replaced and the radiator was taken out to do this. thanks
Did the fault register as a code number ?
Gazza
"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"
Z3 S54 M roadster
, BMW Z1, BMW M3 CSL, Z4M Coupe
"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"
Z3 S54 M roadster
, BMW Z1, BMW M3 CSL, Z4M Coupe-
sapper1592
- Joined: Tue 06 Jul, 2010 15:53
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- Location: Hull
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Mike Fishwick
- Joined: Fri 19 Jun, 2009 10:27
- Posts: 2094
- Location: Daglan, France
Code
Maybe it was a misprint - hence Bosch not being able to help - and should have meant Battery Voltage Low (realative to) B+.
There is no fuel pressure sensor in the system - that is why there is a connector for a fuel pressure gauge on the front of the fuel rail.
There is no fuel pressure sensor in the system - that is why there is a connector for a fuel pressure gauge on the front of the fuel rail.
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sapper1592
- Joined: Tue 06 Jul, 2010 15:53
- Posts: 58
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- Location: Hull
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Mike Fishwick
- Joined: Fri 19 Jun, 2009 10:27
- Posts: 2094
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- Location: Daglan, France
Fuel Pressure
Yes - low fuel pressure equates to weak mixture, but it could equally be one or two of many other things!
Spark plugs come to mind, but a persistant misfire should give a fault code.
Other common problems are air leaks between the airflow sensor and cylinder head, a sticking idle valve, cam sensor - not necessarily a fault code item - the sensor could just be coated in metallic debris, and needs cleaning.
Spark plugs come to mind, but a persistant misfire should give a fault code.
Other common problems are air leaks between the airflow sensor and cylinder head, a sticking idle valve, cam sensor - not necessarily a fault code item - the sensor could just be coated in metallic debris, and needs cleaning.
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sapper1592
- Joined: Tue 06 Jul, 2010 15:53
- Posts: 58
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- Location: Hull
Hi sapper1592. I have done a lot of work/research myself recently in respect of a cold rough start issue. I agree with Mike in that if the rough idle problem is SOLELY related to the first cold start of the day, then the cause is most likely to be a vacuum leak. As Mike says, the most likely place for this vacuum leak is downstream from the MAF sensor boot or the boot itself. I know from experience that if you speak to a BMW expert about this sort of cold start problem and the code reader is giving only a vague reason, this is what he/she would first look at.
Most Zs are 10 years plus old and so replacing original rubber pipework is good preventative maintenance in any event and is relatively inexpensive.
Other authoritative suggestions given to me have been:-
• A failing MAF sensor (I would have expected a code in your case).
• Failing CVV.
• Fuel filter due for change, I believe that in the UK, even the BMW Inspection 2 does not cover changing this item and yet other manufacturers of cars I have had recommend changing the fuel filter every few years. Original items will now be 10-years plus old. I would have thought that this would show up most under full throttle but the suggestion that it can cause cold starting problems came from a very good source.
• Coolant temperature sensor (I would have expected a code in your case).
• Wrong oil and/or sticking valve. No harm with ensuring that the next oil is 5W/40 or similar as recommended for your car. I’ve seen this wrong oil issue mentioned on US BMW forums for people living in places like Alaska! Not sure if the UK climate is severe enough to make this a major issue.
• CPS (you’ve changed your one already)
Most Zs are 10 years plus old and so replacing original rubber pipework is good preventative maintenance in any event and is relatively inexpensive.
Other authoritative suggestions given to me have been:-
• A failing MAF sensor (I would have expected a code in your case).
• Failing CVV.
• Fuel filter due for change, I believe that in the UK, even the BMW Inspection 2 does not cover changing this item and yet other manufacturers of cars I have had recommend changing the fuel filter every few years. Original items will now be 10-years plus old. I would have thought that this would show up most under full throttle but the suggestion that it can cause cold starting problems came from a very good source.
• Coolant temperature sensor (I would have expected a code in your case).
• Wrong oil and/or sticking valve. No harm with ensuring that the next oil is 5W/40 or similar as recommended for your car. I’ve seen this wrong oil issue mentioned on US BMW forums for people living in places like Alaska! Not sure if the UK climate is severe enough to make this a major issue.
• CPS (you’ve changed your one already)
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sapper1592
- Joined: Tue 06 Jul, 2010 15:53
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- Location: Hull
Had it in for a free dignostic as the cel light came on again after the cam sensor had been replaced ,still showing the starnge error. friend took it to his mate at a bmw indy who said it showed it was running lean and they would replace the air flow sensor, so thats been done and all appears at this stage to be going well, fingers crossed. thanks for everyones help. 
