BlueCoupe Posted November 5, 2014 Report Share Posted November 5, 2014 So i got a 255lph fuel pump, and my car runs super rich, i put and inline fuel pressure gauge and it reads 70psi. decided to get a aftermarket fuel pressure regulator and it seems to regulate it down to about 60psi, now for a Sr20de i read it needs to be at about 40psi thats a big difference. Now i thought the FPR was bad so i bought another one and it did the same exact thing. So i either have it hooked up wrong or its a POS or is it possible that my fuel pump is just too strong ? ? ? Going to borrow my buddys FPR in a few days to test it again because i know for a fact his works.. Quote Link to comment
datzenmike Posted November 6, 2014 Report Share Posted November 6, 2014 Maybe it's the gauge that's wrong. Try the gauge on a known good running car. Quote Link to comment
BlueCoupe Posted November 6, 2014 Author Report Share Posted November 6, 2014 Maybe it's the gauge that's wrong. Try the gauge on a known good running car. Well i thought it might be the gauge, but i have 2 gauges, 1 inline and 1 on the FPR but both read the same thing. now i mean i guess both gauges could be broken? but i doubt it if they both read the same thing, and when i pinch the fuel line they both drop to the same pressure. now i forgot if i mentioned i have tried 2 FPRs and both did the same thing. thats the only reason i suspected maybe its possible for the fuel pump to overpower the FPR ? Unless im just super unlikely and both FPRs i received were broken :confused: :crying: Quote Link to comment
BlueCoupe Posted November 6, 2014 Author Report Share Posted November 6, 2014 Put my friends fuel pressure regulator off of his car and on to mine, did the same exact thing, wouldnt get down past 60ish PSI, so i guess that means my fuel pump is just to BA? he had a extra fuel pump thats only 190lph instead of 255lph so ill guess ill give that a try Quote Link to comment
Nuclear Water Boy Posted November 6, 2014 Report Share Posted November 6, 2014 190lph is what I'm running in my S14 SR20DE. Sounds like your pump is likely a much larger unit. The 255lph shouldn't be a problem at all. Only way you can have the pump hooked up wrong would be feeding the fuel rail backwards but I don't believe the engine would run let alone start. Quote Link to comment
BlueCoupe Posted November 6, 2014 Author Report Share Posted November 6, 2014 Put the 190 lph on and runs better but still a little rich, at about 47 psi and can't get it down, my buddy such it's a course induction fuel pump but I'm not really sure what that means Quote Link to comment
BlueCoupe Posted November 7, 2014 Author Report Share Posted November 7, 2014 i also noticed when i rev the engine my fuel pressure drops from like 50 down to 35-40ish, now my fuel filters are new so they arnt clogged and the pump is new so i doubt its going bad what else could cause this? Quote Link to comment
datzenmike Posted November 7, 2014 Report Share Posted November 7, 2014 Put my friends fuel pressure regulator off of his car and on to mine, did the same exact thing, wouldnt get down past 60ish PSI, so i guess that means my fuel pump is just to BA? he had a extra fuel pump thats only 190lph instead of 255lph so ill guess ill give that a try Starting to look like this is normal. Maximum pressure is always going to be higher than when running under load. A 225 and a 190 will have the same maximum pressure only the volume will be different. It's EFI and when warmed up the system is governed by feedback from the O2 sensor. How can it be running rich unless it's in open loop mode??? Quote Link to comment
BlueCoupe Posted November 7, 2014 Author Report Share Posted November 7, 2014 It's EFI and when warmed up the system is governed by feedback from the O2 sensor. How can it be running rich unless it's in open loop mode??? Well enough black smoke comes out of the exhaust to burn your eyes, my A/F gauge is pinned in the yellow, I'm literally at a loss and some days want to set the car on fire because it's not making sense to me. :( Quote Link to comment
MikeRL411 Posted November 7, 2014 Report Share Posted November 7, 2014 Do you have a "return" line from the regulator or fuel rail to the gas tank to take the excess flow? 1 Quote Link to comment
BlueCoupe Posted November 7, 2014 Author Report Share Posted November 7, 2014 Do you have a "return" line from the regulator or fuel rail to the gas tank to take the excess flow? Yes I have a return line from the regulator to the tank Quote Link to comment
datzenmike Posted November 7, 2014 Report Share Posted November 7, 2014 Check adjust the throttle position sensor on the throttle body. It tells the EFI if you are idling or at full throttle. If the EFI is told full throttle it will default to an over rich condition for performance and ignore the O2 sensor. I'm not explaining it very well so find someone with more know how on the workings of the EFI. Quote Link to comment
BlueCoupe Posted November 11, 2014 Author Report Share Posted November 11, 2014 Fixed it, ended up having a clogged return line! Quote Link to comment
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