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Time for an update!
Noticed the car drinking more and more coolant, so i put it away for the winter, started tearing it all down some weeks ago and just finished the job with changing to steel 4.2 head gaskets, and an aftermarket alcohol safe fuel pressure regulator...
Runs fine and passed technical / smog inspection today.
Noticed that pressure slowly goes down after turning the engine off, not sure it thats normal? Also noticed that pressure drops a bit after some time while engine is running when the engine has warmed up for maybe 5 mins. Im thinking that maybe the liquid in the dial/clock/gauge on the pressure regulator gets affected by the heat and starts to show the wrong values?
Will check with an external pressure gauge, but anyone have any experience?
There is a valve in fuel line to prevent fuel pressure go down instantly after engine has just turned off and even the pressure has bleeded down it keeps the fuel line full. By having such valve it prevents air getting in to hot fuel system and making hot start more difficult. 4.0 R engines do have both cam sensors to read cams but they do not not have VVT. Cam sensors are only used for sequential fuel and ignition timing per bank. Usually what is needed for the closed loop fuel correction is no misfires or faulty sensor is detected. If you take any sensor out of the ring you are disabling the closed loop.
Late reply but Thanks Vauxi! This was really good to know: "If you take any sensor out of the ring you are disabling the closed loop." and explains why i got tricked by disconnecting them i guess.
Also want to mention that the after market regulator regulates the pressure correctly but as son as the gauge warms up it starts to show the wrong values, i have verified this with an external gauge on the left side of the fuel rail, so one must take a peak as soon as the engine starts up to verify pressure.
BR
mi
Last edited by RushHourXJR; 07-10-2023 at 02:55 AM.
Reason: spelling