Fuel System Question
03-18-2012, 04:30 PM
#1
3rd Gear Member
Thread Starter
Join Date: Jun 2006
Location: California
Posts: 563
Fuel System Question
I've been suspecting a fuel pump issue with my car, causing it to intermittently shut off while driving and/or not start.
I've found a local deal where I can acquire a 2010 v6 fuel tank, which includes the 2 pumps and the module for $100.
At this point, no shops have been able to replicate and diagnose my problem 100%. They did notice that my fuel pressure fluctuated a bit during idle, but nothing drastic. They also haven't been able to replicate my problem.. although I have!
I want some advice from you guys:
First, the tank should fit my 2007 with no issues correct? I'm not 100% on the compatibility between the 2010 and 2007 fuel system and tank changes.
Second, a shop said it would be ~$400 labor for the switch, so in total I see myself spending a little above $500 for this. Is this something that's really easy to do? Or just let the shop handle it? Hopefully I can get some constructive thoughts and it's been really frustrating for me to be carless for longer than a month
I've found a local deal where I can acquire a 2010 v6 fuel tank, which includes the 2 pumps and the module for $100.
At this point, no shops have been able to replicate and diagnose my problem 100%. They did notice that my fuel pressure fluctuated a bit during idle, but nothing drastic. They also haven't been able to replicate my problem.. although I have!
I want some advice from you guys:
First, the tank should fit my 2007 with no issues correct? I'm not 100% on the compatibility between the 2010 and 2007 fuel system and tank changes.
Second, a shop said it would be ~$400 labor for the switch, so in total I see myself spending a little above $500 for this. Is this something that's really easy to do? Or just let the shop handle it? Hopefully I can get some constructive thoughts and it's been really frustrating for me to be carless for longer than a month
03-18-2012, 06:40 PM
#2
6th Gear Member
Can you provide more details? There IS a TSB for the fuel pump which is related to air bubbles forming during a constant cruise at steady state speeds, then hesitation when you go to accelerate. There is also a very similar symptom when the TCS is on and you go WOT. But nothing that shuts the engine off.
03-19-2012, 12:41 AM
#3
3rd Gear Member
Thread Starter
Join Date: Jun 2006
Location: California
Posts: 563
Can you provide more details? There IS a TSB for the fuel pump which is related to air bubbles forming during a constant cruise at steady state speeds, then hesitation when you go to accelerate. There is also a very similar symptom when the TCS is on and you go WOT. But nothing that shuts the engine off.
Yeah I thought it was that, but I actually think it's the FP failing somehow. I think something is causing the FP to actually shut off when the car is warmed up. Once it's off, it's a variable amount of time before it can be started again. Anywhere from 5 minutes to 45 minutes. I've never had any problems starting it while cold. I actually posted in a thread a while back. I believe it was titled "Car shut off while driving"
03-19-2012, 02:12 PM
#4
4th Gear Member
Join Date: Aug 2007
Location: Stroudsburg, PA
Posts: 1,148
How many miles on the car?
In general when fuel pumps get old they start running hot and will shut down until they cool down - (ultimately they fail and you find your problem). Have you noticed this happening when the tank is low? That would indicate it could be the pump overheating when it isn't fully immersed in fuel to help keep it cool. Also, they get noisy(er) as they get older. When it won't start do you hear the pump energize when you turn the key forward? If not that would also point to the pump.
Not sure about the 2010 interchange but it is probably same. compare pump part #'s. That labor charge seems high to me, seems like a 1 or 2 hour job at the most.
In general when fuel pumps get old they start running hot and will shut down until they cool down - (ultimately they fail and you find your problem). Have you noticed this happening when the tank is low? That would indicate it could be the pump overheating when it isn't fully immersed in fuel to help keep it cool. Also, they get noisy(er) as they get older. When it won't start do you hear the pump energize when you turn the key forward? If not that would also point to the pump.
Not sure about the 2010 interchange but it is probably same. compare pump part #'s. That labor charge seems high to me, seems like a 1 or 2 hour job at the most.
03-19-2012, 08:13 PM
#5
3rd Gear Member
Thread Starter
Join Date: Jun 2006
Location: California
Posts: 563
How many miles on the car?
In general when fuel pumps get old they start running hot and will shut down until they cool down - (ultimately they fail and you find your problem). Have you noticed this happening when the tank is low? That would indicate it could be the pump overheating when it isn't fully immersed in fuel to help keep it cool. Also, they get noisy(er) as they get older. When it won't start do you hear the pump energize when you turn the key forward? If not that would also point to the pump.
Not sure about the 2010 interchange but it is probably same. compare pump part #'s. That labor charge seems high to me, seems like a 1 or 2 hour job at the most.
In general when fuel pumps get old they start running hot and will shut down until they cool down - (ultimately they fail and you find your problem). Have you noticed this happening when the tank is low? That would indicate it could be the pump overheating when it isn't fully immersed in fuel to help keep it cool. Also, they get noisy(er) as they get older. When it won't start do you hear the pump energize when you turn the key forward? If not that would also point to the pump.
Not sure about the 2010 interchange but it is probably same. compare pump part #'s. That labor charge seems high to me, seems like a 1 or 2 hour job at the most.
03-19-2012, 10:42 PM
#6
4th Gear Member
Join Date: Aug 2007
Location: Stroudsburg, PA
Posts: 1,148
The click would be the relay sending power to the pump. The click sound would indicate then indicate the relay isn't the problem. Right after that you should hear a deeper extended tone that comes from the pump turning on and pressurizing the fuel system. That's the sound you need to hear to verify you're hearing or not when it won't start. You want to turn the key all the way off then back on to get that sequence. If the pump isn't coming on then it might be bad or might be the emergency shut off switch. You can jump that switch and then see if it starts. I would try all this when its still working to be sure you know what it should sound like and that you're jump wire is working right.
03-19-2012, 10:50 PM
#7
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Join Date: Jun 2006
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The click would be the relay sending power to the pump. The click sound would indicate then indicate the relay isn't the problem. Right after that you should hear a deeper extended tone that comes from the pump turning on and pressurizing the fuel system. That's the sound you need to hear to verify you're hearing or not when it won't start. You want to turn the key all the way off then back on to get that sequence. If the pump isn't coming on then it might be bad or might be the emergency shut off switch. You can jump that switch and then see if it starts. I would try all this when its still working to be sure you know what it should sound like and that you're jump wire is working right.
I know what you mean by the click of the relay. It's not a click, it's a thunk. http://www.youtube.com/watch?v=wSdfFt-gbFM
At about 20 seconds or so, when the key is on the 2nd turn, you can hear the fuel pump make a slight "clunk" then the whirring starts. And that's the sound that I DON'T hear whenever the car doesn't want to start and/or stalls and I try to start it. I don't think it's the inertia switch - it's never been tripped. I've tried it as well. This has been really frustrating for me, but hopefully I can get it resolved soon.
03-19-2012, 11:52 PM
#8
4th Gear Member
Join Date: Aug 2007
Location: Stroudsburg, PA
Posts: 1,148
OK, great so you comfortable the pump is not running. My first guess would be pump but with the low miles it would have to be defective. I would want to verify its getting power first. If you're lucky you just have a bad inertia switch so I would test or bypass it to be sure. There must be a resistance test you can do on the pump as well that would confirm its bad.
03-20-2012, 12:50 AM
#9
3rd Gear Member
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Join Date: Jun 2006
Location: California
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OK, great so you comfortable the pump is not running. My first guess would be pump but with the low miles it would have to be defective. I would want to verify its getting power first. If you're lucky you just have a bad inertia switch so I would test or bypass it to be sure. There must be a resistance test you can do on the pump as well that would confirm its bad.
03-20-2012, 06:09 AM
#10
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Hook up a pressure gauge, run the car till it fails, have a look at the gauge and you see if it's a fuel pump issue. A fuel rail adapter gauge is about $60 or a test line and gauge about $30. I use the test line and a sender for my fuel pressure gauge.
Fuel pressure test line (remove the nipple and install the gauge
Rail adapter
Fuel pressure test line (remove the nipple and install the gauge
Rail adapter