Fuel rail pressure regulator
Discussion
Hi guys,
Since the beginning with my S3C, I think there is a problem with full throttle response. That's not perfect, the engine hesitates. Some time it runs fine, and some time it struggles. I was focused on the ignition because a lot of parts was in bad conditions. Now, all is new or clean, so the problem don't come from this side. The other side is the fuel system.
Yesterday, I took a look to the fuel pressure regulator and discovered the vacuum hose was not correctly connected. It came into my hand even thought I just grazed it.
After re-plugging it, I tested the car and the throttle response is far better, but not yet perfect. So I took a look to a new pressure regulator.
Burton Power sells a FSE adjustable regulator
https://www.burtonpower.com/power-boost-valve-ford...
TVR-Parts sells a more genuine look-a-like one
https://tvr-parts.com/tvr-parts/part-details/tvr-l...
Does anybody tested this product ?
Where is it possible to plug a gauge on the rail to control the fuel pressure ?
Regards.
Since the beginning with my S3C, I think there is a problem with full throttle response. That's not perfect, the engine hesitates. Some time it runs fine, and some time it struggles. I was focused on the ignition because a lot of parts was in bad conditions. Now, all is new or clean, so the problem don't come from this side. The other side is the fuel system.
Yesterday, I took a look to the fuel pressure regulator and discovered the vacuum hose was not correctly connected. It came into my hand even thought I just grazed it.
After re-plugging it, I tested the car and the throttle response is far better, but not yet perfect. So I took a look to a new pressure regulator.
Burton Power sells a FSE adjustable regulator
https://www.burtonpower.com/power-boost-valve-ford...
TVR-Parts sells a more genuine look-a-like one
https://tvr-parts.com/tvr-parts/part-details/tvr-l...
Does anybody tested this product ?
Where is it possible to plug a gauge on the rail to control the fuel pressure ?
Regards.
I never order to the USA because this cheap 43€ (£38) part will cost me 69€ (60 GBP) due to custom taxes and administration costs. (and that would be exactly the same thing with UK as soon as the Brexit would be effective 
) And also, If I have to replace it, I prefer improving the system if it's possible.
) And also, If I have to replace it, I prefer improving the system if it's possible.
Some questions before you go spending money on a FPR:
1. What is your current fuel pressure under full load (zero manifold depression), and is it within spec?
2. What is your AFR under full load? - IE do you even know if you're running lean or rich?
3. Are you confident in the condition of your injectors? - IE have you checked them on an oscilloscope or recently had them cleaned and flow matched?
4. Can you map your ECU - IE can you make changes to your fuel table if you start blindly messing about with your fuel pressure?
If the answer is NO...
to any one (or more than one) of the above questions I would strongly advise against messing with your fuel pressure in the blind hope you will fix your flat spot, and don't assume just because you've thrown a bunch of ignition parts at the car the ignition side is now perfect.
The way to fix your problem is not to play the 'Parts Darts' game but to test, re-test, and keep testing following a logical produce because like this you can't help but find the true fault. But only do so if you have the right diagnostic equipment and are completely confident you understand exactly how the system or systems you are testing are designed to work in the first place.
You also need to establish beyond any reasonable doubt you do not have an ignition related misfire under load, and simply fitting a few new ignition parts in absolutely no way proves this. You must establish your true and exact fuel pressure under load and compare it with the correct factory specification, just guessing it's out of spec is not the way to fix the problem as you'll very likely be unnecessarily be wasting your money on a new FPR.
Even if you do see a lean AFR combined with low fuel pressure under load whats to say it's not a weak fuel pump, a low voltage supply to a healthy fuel pump, a partially collapsed fuel hose, a blocked fuel filter, a pinched copper fuel line or fuel injector issues for that matter?
If you go to your doctor with chest pains he doesn't just guess and send you immediately for a heart bypass, he runs a myriad of tests before he makes his diagnosis. More specifically your doctor is looking for at least two (three is better) results form different tests that together combine to conclusively point him towards a correct and inarguable diagnosis.. Following these tests and in my chest pain example the problem could easily be proved to be nothing more life threatening or hard to correct than severe indigestion, if you found that out after having a full heart bypass you wouldn't be very happy with your doctor would you
The methodology behind intelligent mechanical diagnostics is no different to that of medical diagnostics, it's all about understanding the way the system is designed to work then following a systematic and logical set of tests to establish without any reasonable doubt what the true cause of the symptom is.
So before reaching for your wallet get busy testing, then analyse the data from your tests before considering your next steps. In this case a simple fuel pressure test is an essential starting point, also use a test meter on your fuel pump as poor voltage supply is a common issue which is often easily fixed by improving the ground connection at the pump. On the ignition side there are many revealing tests you can complete with a basic multimeter, however if you can find an old skool mechanic with a Sun tuner machine... better still
If you're considering a fitting a new FPR without even proving you definitely have low fuel pressure under load you need to stop and reconsider your approach, even if you do find you have a fuel pressure issue it could so easily be caused by many different things so the idea of just sticking a new FPR on the car in the blind hope it'll cure the problem becomes a very flawed approach. At the end of the day you could easily end up renewing the entire fuel system at great expense for no reason at all only to discover the issue was an ignition related misfire all along.
My best friendly advice therefore is to follow the approach of your doctor and replace guess work with more testing, I'd wish you good luck with finding your fault but luck of course has nothing to do with good diagnostic practice.
Dave.
1. What is your current fuel pressure under full load (zero manifold depression), and is it within spec?
2. What is your AFR under full load? - IE do you even know if you're running lean or rich?
3. Are you confident in the condition of your injectors? - IE have you checked them on an oscilloscope or recently had them cleaned and flow matched?
4. Can you map your ECU - IE can you make changes to your fuel table if you start blindly messing about with your fuel pressure?
If the answer is NO...
to any one (or more than one) of the above questions I would strongly advise against messing with your fuel pressure in the blind hope you will fix your flat spot, and don't assume just because you've thrown a bunch of ignition parts at the car the ignition side is now perfect.The way to fix your problem is not to play the 'Parts Darts' game but to test, re-test, and keep testing following a logical produce because like this you can't help but find the true fault. But only do so if you have the right diagnostic equipment and are completely confident you understand exactly how the system or systems you are testing are designed to work in the first place.
You also need to establish beyond any reasonable doubt you do not have an ignition related misfire under load, and simply fitting a few new ignition parts in absolutely no way proves this. You must establish your true and exact fuel pressure under load and compare it with the correct factory specification, just guessing it's out of spec is not the way to fix the problem as you'll very likely be unnecessarily be wasting your money on a new FPR.
Even if you do see a lean AFR combined with low fuel pressure under load whats to say it's not a weak fuel pump, a low voltage supply to a healthy fuel pump, a partially collapsed fuel hose, a blocked fuel filter, a pinched copper fuel line or fuel injector issues for that matter?
If you go to your doctor with chest pains he doesn't just guess and send you immediately for a heart bypass, he runs a myriad of tests before he makes his diagnosis. More specifically your doctor is looking for at least two (three is better) results form different tests that together combine to conclusively point him towards a correct and inarguable diagnosis.. Following these tests and in my chest pain example the problem could easily be proved to be nothing more life threatening or hard to correct than severe indigestion, if you found that out after having a full heart bypass you wouldn't be very happy with your doctor would you
The methodology behind intelligent mechanical diagnostics is no different to that of medical diagnostics, it's all about understanding the way the system is designed to work then following a systematic and logical set of tests to establish without any reasonable doubt what the true cause of the symptom is.
So before reaching for your wallet get busy testing, then analyse the data from your tests before considering your next steps. In this case a simple fuel pressure test is an essential starting point, also use a test meter on your fuel pump as poor voltage supply is a common issue which is often easily fixed by improving the ground connection at the pump. On the ignition side there are many revealing tests you can complete with a basic multimeter, however if you can find an old skool mechanic with a Sun tuner machine... better still
If you're considering a fitting a new FPR without even proving you definitely have low fuel pressure under load you need to stop and reconsider your approach, even if you do find you have a fuel pressure issue it could so easily be caused by many different things so the idea of just sticking a new FPR on the car in the blind hope it'll cure the problem becomes a very flawed approach. At the end of the day you could easily end up renewing the entire fuel system at great expense for no reason at all only to discover the issue was an ignition related misfire all along.
My best friendly advice therefore is to follow the approach of your doctor and replace guess work with more testing, I'd wish you good luck with finding your fault but luck of course has nothing to do with good diagnostic practice.
Dave.
1. There are 2 possible regulators: one for the pressed-steel fuel rail and one for the cast-aluminium rail. They work the same, but the connections are in different locations, so make sure you get the same nne.
2. If you use a pressure gauge, check that it doesn't have a non-return valve at the gauge connection. (It may also be a cylinder-compression gauge). Unless you remove the valve, it will read the high static pressure but NOT show you a pressure reduction! Ask me how I know this!
2. If you use a pressure gauge, check that it doesn't have a non-return valve at the gauge connection. (It may also be a cylinder-compression gauge). Unless you remove the valve, it will read the high static pressure but NOT show you a pressure reduction! Ask me how I know this!
GreenV8S said:
Measure the pressure before you start replacing parts. Since the pressure regulator is on the return side of the fuel rail, you can measure the pressure by a T connector on the supply side.
Of course I will. Thanks for the advice for the T connector on supply.phillpot said:
There is a valve, like a tyre valve, on the fuel rail.
Ok, I will also look for it. 2 measures is better than one mentall said:
1. There are 2 possible regulators: one for the pressed-steel fuel rail and one for the cast-aluminium rail. They work the same, but the connections are in different locations, so make sure you get the same nne.
Thank you for the warning. I had seen that point. Mine is a pressed-steel rail with a "vertical bolt" regulator as it is called, to identify one type and the other.mentall said:
2. If you use a pressure gauge, check that it doesn't have a non-return valve at the gauge connection. (It may also be a cylinder-compression gauge). Unless you remove the valve, it will read the high static pressure but NOT show you a pressure reduction! Ask me how I know this!
You're right, I'll be careful on this point.And for the rest.... I will not wast my time to reply to a priest sermon.
Fefeu52 said:
You're right, I'll be careful on this point.
And for the rest.... I will not wast my time to reply to a priest sermon.
Its all good advice and well meant.And for the rest.... I will not wast my time to reply to a priest sermon.
Fortunately it seems you're finally following it which will save you money and dramatically improve your chances of finding the fault.
Just resist the temptation to return to the guessing approach as it'll get you nowhere fast.
Useful pictures here :
http://www.fordopedia.org/parts-catalog/24-29-v6/B...
And a lot of useful informations here... with a translator :
http://www.jorgen.tronderford.com/norske/manualen/...
http://www.fordopedia.org/parts-catalog/24-29-v6/B...
And a lot of useful informations here... with a translator :
http://www.jorgen.tronderford.com/norske/manualen/...
ChimpOnGas said:
Its all good advice and well meant.
Fortunately it seems you're finally following it which will save you money and dramatically improve your chances of finding the fault.
Just resist the temptation to return to the guessing approach as it'll get you nowhere fast.
Don't try to find any sens to your pathetic liturgy. I will only do what I planed to do, checking the fuel pressure (the last question of my first message), and replace the regulator by an adjustable one (the beginning). Thanks to the others for their useful advice and warning... as usual.Fortunately it seems you're finally following it which will save you money and dramatically improve your chances of finding the fault.
Just resist the temptation to return to the guessing approach as it'll get you nowhere fast.
And I would give you feedback If I have something useful to say.
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