Fuel Pressure Regulator Blues
#1
Fuel Pressure Regulator Blues
82' Turbo 2+2
The dangers of the search function and having the shop manual.
So I was still having issues with a warm car and power intermittently cutting out. I read up a bit more on the fuel pressure regulator, and decided that what I thought was the check valve could be the valve leaking inside the FPR. So I did a little experiment and unhooked the vac line to the FPR and went for a cruise.
Well, it ran SOOO much better I couldn't believe it! I was down a little power at the top end (likely due to the FPR not increasing pressure with turbo boost to match the 36.3 psi difference) but I was not losing power every where else in the range!
So like a good kid, I got on the search function, and read about all the problems that people have had with the FPR in these aging cars. So my question is:
Do you even need an FPR anyways? The fuel pump has a relief valve if the pressure gets too high, and someone wrote (convincingly) that the injectors will regulate fuel if it is too rich or lean, so is there any danger of no FPR? I read about the hard starts when the pressure leaks back to the tank, but it sounds like most of the aftermarket ones leak anyways.
So will I blow up my injectors, or the rubber lines with no FPR? The relief starts to open around 43 psi, (according to the manual) so that shouldn't blow anything up. Unless it is like diesels that use the flow back to the tank to moderate temperatures in fuel tanks and lines...
Comments?
Oh, and because finding any FPR for this car with stock fitment will be a pain, anyone have any OEM suggestions from the wrecker, or do I have to go aftermarket? (Hong Kong?)
The dangers of the search function and having the shop manual.
So I was still having issues with a warm car and power intermittently cutting out. I read up a bit more on the fuel pressure regulator, and decided that what I thought was the check valve could be the valve leaking inside the FPR. So I did a little experiment and unhooked the vac line to the FPR and went for a cruise.
Well, it ran SOOO much better I couldn't believe it! I was down a little power at the top end (likely due to the FPR not increasing pressure with turbo boost to match the 36.3 psi difference) but I was not losing power every where else in the range!
So like a good kid, I got on the search function, and read about all the problems that people have had with the FPR in these aging cars. So my question is:
Do you even need an FPR anyways? The fuel pump has a relief valve if the pressure gets too high, and someone wrote (convincingly) that the injectors will regulate fuel if it is too rich or lean, so is there any danger of no FPR? I read about the hard starts when the pressure leaks back to the tank, but it sounds like most of the aftermarket ones leak anyways.
So will I blow up my injectors, or the rubber lines with no FPR? The relief starts to open around 43 psi, (according to the manual) so that shouldn't blow anything up. Unless it is like diesels that use the flow back to the tank to moderate temperatures in fuel tanks and lines...
Comments?
Oh, and because finding any FPR for this car with stock fitment will be a pain, anyone have any OEM suggestions from the wrecker, or do I have to go aftermarket? (Hong Kong?)
#2
if you weren't so lazy you would find fprs available: for instance
whoever told you the injectors would regulate is so full of BS knows little or nothing about fluid mechanics and probably less about the fuel injection system
if you had put a pressure gage on the fuel ring you would know what is going on with your system.
whoever told you the injectors would regulate is so full of BS knows little or nothing about fluid mechanics and probably less about the fuel injection system
if you had put a pressure gage on the fuel ring you would know what is going on with your system.
#3
Ha, well I would never have thought of Amazon for car parts, but I didn't see much on Ebay. And I agree, the pressure gauge on the rail is the next thing needed, but I am trying not to just throw parts at the car and figure out what is actually wrong with it.
On the topic of fuel pressure gauges, does anyone dash-mount one, or is it typically left on the regulator, like on most of the aftermarket FPR's?
On the topic of fuel pressure gauges, does anyone dash-mount one, or is it typically left on the regulator, like on most of the aftermarket FPR's?
#4
I've got mine dash mounted in my 86T. if it is under the hood you can't see what happens during starting, acceleration etc. while at it put in a boost gage unless the factory stock one appears to be working. boost controller makes it faster.
#6
Last edited by Skully; 07-23-2015 at 02:59 PM.
#7
Well, the new fuel pressure reg is in, and it runs like a charm (finally). Out of sheer curiousity, what does everyone with a variable regulator set theirs at? I found it didn't seem to run as well at the recommended 34 psi, so I set it about 37 and it seems to improve driveability. Maybe the gauge isn't all that accurate...
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