Cayenne S Stalling Problems How do I test the fuel pump?
07-17-2014, 07:08 PM
#31
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I just recently joined the ranks as a Porsche owner. I bought an 04 Cayenne S with 21K miles on it.
Last night the car started to stall. I start the engine and about 10 seconds in it shuts off.
I read many post including this one and took a few suggestions.
- Removed the MAF sensor to attempt to change modes.
- I used both hands to pump air pressure into the filter and the car maintained pressure and stay on until I stopped pumping. It then shut off.
Last night the car started to stall. I start the engine and about 10 seconds in it shuts off.
I read many post including this one and took a few suggestions.
- Removed the MAF sensor to attempt to change modes.
- I used both hands to pump air pressure into the filter and the car maintained pressure and stay on until I stopped pumping. It then shut off.
- I then replaced the MAF sensors and am still getting same results.
I read that I should remove the fuel pump relay to test the drivers side pump.
Any other suggestions if that doesn't work.
07-18-2014, 02:28 PM
#33
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Do you hear any sort of whoosh noise when you open the cap? If so - your vent system for the fuel tank is plugged up and you're pulling a vacuum on the tank - causing the gasoline to eventually stop being pumped. Best guess would be a damaged filler cap - but I'm not sure if the intake vent is in the cap or part of the tank venting system.
In either case - when it stalls - try opening the cap (listening for any noise) then see if it starts. If it does - the vent system is where I'd look for the problem, chances are your pumps are just fine.
07-20-2014, 05:09 PM
#34
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Still not clear on what you referred to as a "filter" above. Do you mean the gas filler?
Do you hear any sort of whoosh noise when you open the cap? If so - your vent system for the fuel tank is plugged up and you're pulling a vacuum on the tank - causing the gasoline to eventually stop being pumped. Best guess would be a damaged filler cap - but I'm not sure if the intake vent is in the cap or part of the tank venting system.
In either case - when it stalls - try opening the cap (listening for any noise) then see if it starts. If it does - the vent system is where I'd look for the problem, chances are your pumps are just fine.
Do you hear any sort of whoosh noise when you open the cap? If so - your vent system for the fuel tank is plugged up and you're pulling a vacuum on the tank - causing the gasoline to eventually stop being pumped. Best guess would be a damaged filler cap - but I'm not sure if the intake vent is in the cap or part of the tank venting system.
In either case - when it stalls - try opening the cap (listening for any noise) then see if it starts. If it does - the vent system is where I'd look for the problem, chances are your pumps are just fine.
then i pushed my ear to driver side feul pump
and i didnt hear that niose whats should i do?
07-21-2014, 01:04 AM
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tonight i had drive for 2 hour then car stalled and i opend the cap but it stalled again i stopped the car and opend the rear seat then i pushed my ear to passenger side feul pump i hear noise tells its working (like mmmmmm)
then i pushed my ear to driver side feul pump
and i didnt hear that niose whats should i do?
then i pushed my ear to driver side feul pump
and i didnt hear that niose whats should i do?
Pull one fuel pump fuse - then start the car. If it starts - the other fuel pump is GOOD. Stop the car. Replace the fuse you removed. Pull the OTHER fuel pump fuse and try to start the car - if it starts - both pumps are good. If it doesn't - the OTHER fuel pump is bad.
The system automatically switches to the other pump if it detects one fuse out. This works best with more than 1/2 tank of fuel.
I'm sure someone will post the pump use logic - I've seen it described here before.
Meanwhile I see explanation of what you were doing with a "filter" and no mention of doing a fuel pressure test - and without doing that - I don't think you're taking my advice seriously and won't continue offering it, except to say don't drive the car for more than 90 minutes...
07-21-2014, 08:51 AM
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The pumps don't always both run at the same time. It depends on fuel level, and I suspect the angle the vehicle is at. Once again - pulling fuses is the best way to test if you have a dead pump.
Pull one fuel pump fuse - then start the car. If it starts - the other fuel pump is GOOD. Stop the car. Replace the fuse you removed. Pull the OTHER fuel pump fuse and try to start the car - if it starts - both pumps are good. If it doesn't - the OTHER fuel pump is bad.
The system automatically switches to the other pump if it detects one fuse out. This works best with more than 1/2 tank of fuel.
I'm sure someone will post the pump use logic - I've seen it described here before.
Meanwhile I see explanation of what you were doing with a "filter" and no mention of doing a fuel pressure test - and without doing that - I don't think you're taking my advice seriously and won't continue offering it, except to say don't drive the car for more than 90 minutes...
Pull one fuel pump fuse - then start the car. If it starts - the other fuel pump is GOOD. Stop the car. Replace the fuse you removed. Pull the OTHER fuel pump fuse and try to start the car - if it starts - both pumps are good. If it doesn't - the OTHER fuel pump is bad.
The system automatically switches to the other pump if it detects one fuse out. This works best with more than 1/2 tank of fuel.
I'm sure someone will post the pump use logic - I've seen it described here before.
Meanwhile I see explanation of what you were doing with a "filter" and no mention of doing a fuel pressure test - and without doing that - I don't think you're taking my advice seriously and won't continue offering it, except to say don't drive the car for more than 90 minutes...
about fuel filter at first time that issue appears the porsche company changed fuel filter
i dont know what it is
07-21-2014, 04:43 PM
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The pumps don't always both run at the same time. It depends on fuel level, and I suspect the angle the vehicle is at. Once again - pulling fuses is the best way to test if you have a dead pump.
Pull one fuel pump fuse - then start the car. If it starts - the other fuel pump is GOOD. Stop the car. Replace the fuse you removed. Pull the OTHER fuel pump fuse and try to start the car - if it starts - both pumps are good. If it doesn't - the OTHER fuel pump is bad.
The system automatically switches to the other pump if it detects one fuse out. This works best with more than 1/2 tank of fuel.
I'm sure someone will post the pump use logic - I've seen it described here before.
Meanwhile I see explanation of what you were doing with a "filter" and no mention of doing a fuel pressure test - and without doing that - I don't think you're taking my advice seriously and won't continue offering it, except to say don't drive the car for more than 90 minutes...
Pull one fuel pump fuse - then start the car. If it starts - the other fuel pump is GOOD. Stop the car. Replace the fuse you removed. Pull the OTHER fuel pump fuse and try to start the car - if it starts - both pumps are good. If it doesn't - the OTHER fuel pump is bad.
The system automatically switches to the other pump if it detects one fuse out. This works best with more than 1/2 tank of fuel.
I'm sure someone will post the pump use logic - I've seen it described here before.
Meanwhile I see explanation of what you were doing with a "filter" and no mention of doing a fuel pressure test - and without doing that - I don't think you're taking my advice seriously and won't continue offering it, except to say don't drive the car for more than 90 minutes...
I did two test on my car and these are results
1:
I pulled one of the pump fuse, then car starts normally and i test it on driving and nothing was wrong.
then i Stopped the car and Replaced the fuse was removed and i Pull the OTHER fuel pump fuse.
again it starts normally and i test it on driving and nothing was wrong.
2: in the second test
i replaced two fuse in their place and drive the care until engine turn off by itself,
it takes about 2 hour again
then I turned engine on again and pulled left pump fuse,
THE ENGINE TURNED OFF ITSELF.
I replaced the left pump fuse(no.14 in engine box fuse)
and then I turned engine on again and pulled right pump fuse (no.13 in engine box fuse)
THE ENGINE DID NOT TURN OFF ITSELF,
and i drive the car, it stalls so much more (everytime i pushed the accelerator pedal)
Is it means the passenger pomp dosent work correctly?
Is it possible that a pomp get heated after a time of working and die ?
07-21-2014, 10:19 PM
#38
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I did two test on my car and these are results
1:
I pulled one of the pump fuse, then car starts normally and i test it on driving and nothing was wrong.
then i Stopped the car and Replaced the fuse was removed and i Pull the OTHER fuel pump fuse.
again it starts normally and i test it on driving and nothing was wrong.
1:
I pulled one of the pump fuse, then car starts normally and i test it on driving and nothing was wrong.
then i Stopped the car and Replaced the fuse was removed and i Pull the OTHER fuel pump fuse.
again it starts normally and i test it on driving and nothing was wrong.
2: in the second test
i replaced two fuse in their place and drive the care until engine turn off by itself,
it takes about 2 hour again
then I turned engine on again and pulled left pump fuse,
THE ENGINE TURNED OFF ITSELF.
a. Engine/ignition OFF
b. Remove the fuse of the pump you're not testing
c. Try to start the vehicle.
I replaced the left pump fuse(no.14 in engine box fuse)
and then I turned engine on again and pulled right pump fuse (no.13 in engine box fuse)
THE ENGINE DID NOT TURN OFF ITSELF,
and i drive the car, it stalls so much more (everytime i pushed the accelerator pedal)
Is it means the passenger pomp dosent work correctly?
Is it possible that a pomp get heated after a time of working and die ?
The system does a switchover when there is a pump failure only on startup.. which is why to really test it you have to STOP the engine and RESTART it to perform the test.
I'd suggest repeating your 2 hour test again - but this time - stop the engine, remove the fuse, try restarting it. Then do the other pump.
I think you're getting closer..
07-22-2014, 06:51 AM
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07-22-2014, 01:20 PM
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The reason I asked about fuel level is there is some level (forget what, but I don't think 1/2 tank) where the pumps switch over or both turn on. Someone once posted the pump logic for when they run, and it's not "simple" - plus one pump feeds fuel to the well that the other pump sits in to keep it from running dry when the truck is at a severe angle.
I think doing the test again - the right way - at the two hour mark will turn up the problem. It's likely a pump, but given the expense and the pain involved in replacing them, it would be good to be sure.
I think doing the test again - the right way - at the two hour mark will turn up the problem. It's likely a pump, but given the expense and the pain involved in replacing them, it would be good to be sure.
07-22-2014, 05:58 PM
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The reason I asked about fuel level is there is some level (forget what, but I don't think 1/2 tank) where the pumps switch over or both turn on. Someone once posted the pump logic for when they run, and it's not "simple" - plus one pump feeds fuel to the well that the other pump sits in to keep it from running dry when the truck is at a severe angle.
I think doing the test again - the right way - at the two hour mark will turn up the problem. It's likely a pump, but given the expense and the pain involved in replacing them, it would be good to be sure.
I think doing the test again - the right way - at the two hour mark will turn up the problem. It's likely a pump, but given the expense and the pain involved in replacing them, it would be good to be sure.
I did 3 another tests and these are results:
1:while the fuel tank is on 1/4 of capacity:
A: I turned engine off and remove the key then ,pulled out left fuel pump fuse(no.14 in engine fuse box):
engine started normally
but for 15 second the rpm up and down between 500-700.
In driving test (10min) "ENGINE WAS NOT STALLING"
B: I turned engine off and remove the key then ,pulled out right fuel pump fuse(no.13 in engine fuse box):
engine started normally
In driving test (5min) "ENGINE STALLED 2 Time"
After these result Immediately i filled tank
2:while the fuel tank is full:
A:I turned engine off and remove the key then ,pulled out left fuel pump fuse(no.14 in engine fuse box):
engine started normally
In driving test (10min) "ENGINE WAS NOT STALLING"
B:I turned engine off and remove the key then ,pulled out right fuel pump fuse(no.13 in engin fuse box):
engine started normally
but for 15 second the rpm up and down between 500-700.
In driving test (30min) "ENGINE WAS NOT STALLING"
last test
3:I turned engine off and remove the key then replaced both side fuse pump in their place:
engine started normally
In driving test (10min) "ENGINE WAS NOT STALLING"
(stalling means :while driving Abruptly rpm goes near 0 and after awhile it got back)
07-22-2014, 07:36 PM
#42
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OK. Interesting test results.
One thing to consider - if the pump(s) start to fail when they heat up - filling the tank will cool them down - perhaps enough that they won't fail. It's also easier to pump a full tank than a partially full one.
Given the symptoms that you see whenever you remove the fuse for the right pump - I'd be suspicious of the left side one.
It also still be interesting to see what is happening with the fuel pressure when all this is going on. Don't know where you are - but any reasonably equipped shop should have a fuel pressure test gauge. It's easy to hook up - there is a fitting for it on the front of the fuel rail (that the injectors get fuel from.) The fitting is a "Schrader" valve - very similar to a valve stem on a tire. You need a gauge that reads to about 5-bar max I believe (would have to look it up.)
Right now - I'd be leaning toward your left side fuel pump - but these are often replaced in pairs since it seems when one goes bad the other one isn't far behind it.
One thing to consider - if the pump(s) start to fail when they heat up - filling the tank will cool them down - perhaps enough that they won't fail. It's also easier to pump a full tank than a partially full one.
Given the symptoms that you see whenever you remove the fuse for the right pump - I'd be suspicious of the left side one.
It also still be interesting to see what is happening with the fuel pressure when all this is going on. Don't know where you are - but any reasonably equipped shop should have a fuel pressure test gauge. It's easy to hook up - there is a fitting for it on the front of the fuel rail (that the injectors get fuel from.) The fitting is a "Schrader" valve - very similar to a valve stem on a tire. You need a gauge that reads to about 5-bar max I believe (would have to look it up.)
Right now - I'd be leaning toward your left side fuel pump - but these are often replaced in pairs since it seems when one goes bad the other one isn't far behind it.
07-23-2014, 04:02 AM
#43
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OK. Interesting test results.
One thing to consider - if the pump(s) start to fail when they heat up - filling the tank will cool them down - perhaps enough that they won't fail. It's also easier to pump a full tank than a partially full one.
Given the symptoms that you see whenever you remove the fuse for the right pump - I'd be suspicious of the left side one.
It also still be interesting to see what is happening with the fuel pressure when all this is going on. Don't know where you are - but any reasonably equipped shop should have a fuel pressure test gauge. It's easy to hook up - there is a fitting for it on the front of the fuel rail (that the injectors get fuel from.) The fitting is a "Schrader" valve - very similar to a valve stem on a tire. You need a gauge that reads to about 5-bar max I believe (would have to look it up.)
Right now - I'd be leaning toward your left side fuel pump - but these are often replaced in pairs since it seems when one goes bad the other one isn't far behind it.
One thing to consider - if the pump(s) start to fail when they heat up - filling the tank will cool them down - perhaps enough that they won't fail. It's also easier to pump a full tank than a partially full one.
Given the symptoms that you see whenever you remove the fuse for the right pump - I'd be suspicious of the left side one.
It also still be interesting to see what is happening with the fuel pressure when all this is going on. Don't know where you are - but any reasonably equipped shop should have a fuel pressure test gauge. It's easy to hook up - there is a fitting for it on the front of the fuel rail (that the injectors get fuel from.) The fitting is a "Schrader" valve - very similar to a valve stem on a tire. You need a gauge that reads to about 5-bar max I believe (would have to look it up.)
Right now - I'd be leaning toward your left side fuel pump - but these are often replaced in pairs since it seems when one goes bad the other one isn't far behind it.
i wanna know with these result can we believe the problem is because of pumps behavior ?
and which pomp is more suspicious?
07-24-2014, 06:17 PM
#44
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sorry im not a mechanic and i cant open the engine cover and i dont know where is the fuel rail and fuel valve , the fear is doing something wrong and knock down something else
i wanna know with these result can we believe the problem is because of pumps behavior ?
and which pomp is more suspicious?
i wanna know with these result can we believe the problem is because of pumps behavior ?
and which pomp is more suspicious?
08-16-2014, 12:07 AM
#45
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Hello Moham ad ... were you able to solve the problem on your cayenne ... I have exactly the same problem as yours and had no clue if it's related to the Fuel system or air intake ... if you were able to resolve your issues appreciate if you can post here how you fixed it or you can also mail me ...
thanks
thanks