I'm having problems with my car hard starting, and once it does run, if you try to accelerate it seems to hit dead spots in the rev range, ie you get to 2000rpm, the car seems to die, slows down as if you are giving no gas. If you keep giving gas the car will eventually pick up and continue accelerating as normal, and then it will happen again at a different point in the rev range.
Its not always at the same point, it seems to happen randomly. Also the car idles really rough.
I have just put in a new fuel pump relay, as well as jumping the relay with a piece of wire, and results are the same.
I just bought a fuel pressure test kit, and installed it in the fuel line that connects to the rear of the fuel rail, closest to the firewall of my car. When trying to start fuel pressure is at zero, and after cranking for a long time, it will eventually hit 10psi. When the car is shut off fuel pressure drops immediately. If I jump the relay with the car off, pressure goes to 10psi and then stops, car will then start more easily than with relay in, and then idles rough with the pressure going between 10 and 12 psi.
I'm 99% sure its my fuel pressure regulator, also I should mention that when I first noticed this I checked my engine and the vacuum line to the FPR was broken, so I replaced it. The size of hose I replaced it with was by eye exactly the same, but I suppose that it could have been very slightly different, would that make much of a difference? And would that error in size allow the FPR to drop all the pressure almost instantly? Also since I'm unsure of how long the vacuum line was broken, most likely just a day or so, could my driving of the car with the broken line have caused the FPR to fail, so that even a new vacuum line would not solve the problem?
One last thing, I am running a larger, in tank fuel pump, and I have converted my car from dual pumps to single, without running a new wire to the new pump. I have seen some posts advising that this wire be changed, but from other things I have read it sounds like the stock wiring should be able to handle it. I also spoke with FLG, and he is running the same set up as me with a turbo and not seeing issues, and with the turbo his car is drawing much more fuel than mine while still not causing the wires to fail, leading me to believe that this is not the issue, but I felt I should mention it.
So is the next logical step to replace the fuel pressure regulator?
Its not always at the same point, it seems to happen randomly. Also the car idles really rough.
I have just put in a new fuel pump relay, as well as jumping the relay with a piece of wire, and results are the same.
I just bought a fuel pressure test kit, and installed it in the fuel line that connects to the rear of the fuel rail, closest to the firewall of my car. When trying to start fuel pressure is at zero, and after cranking for a long time, it will eventually hit 10psi. When the car is shut off fuel pressure drops immediately. If I jump the relay with the car off, pressure goes to 10psi and then stops, car will then start more easily than with relay in, and then idles rough with the pressure going between 10 and 12 psi.
I'm 99% sure its my fuel pressure regulator, also I should mention that when I first noticed this I checked my engine and the vacuum line to the FPR was broken, so I replaced it. The size of hose I replaced it with was by eye exactly the same, but I suppose that it could have been very slightly different, would that make much of a difference? And would that error in size allow the FPR to drop all the pressure almost instantly? Also since I'm unsure of how long the vacuum line was broken, most likely just a day or so, could my driving of the car with the broken line have caused the FPR to fail, so that even a new vacuum line would not solve the problem?
One last thing, I am running a larger, in tank fuel pump, and I have converted my car from dual pumps to single, without running a new wire to the new pump. I have seen some posts advising that this wire be changed, but from other things I have read it sounds like the stock wiring should be able to handle it. I also spoke with FLG, and he is running the same set up as me with a turbo and not seeing issues, and with the turbo his car is drawing much more fuel than mine while still not causing the wires to fail, leading me to believe that this is not the issue, but I felt I should mention it.
So is the next logical step to replace the fuel pressure regulator?
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