as we all know neons on cold starts have a knocking noise until it warms up right? well I changed my FPR and it no longer has the cold start noise. which means the FPR was leaking and washing the piston rings with gas. now that the new FPR is accualy returning the fuel to the pump I no longer have that cold start knock. it is 30 degree's today and i haven't heard the knock since the new FPR. which means I need to change my oil because its probably diluted. from what I hear your Fuel Pressure Regulator should mke a Hiss noise so you know its returning the fuel instead of flooding the motor. I'm just letting you guys knowfrom my exeriance.

 

Piston slap is different than the issue you are talking about. Regardless, I'm not buying that the FPR is bad from the factory on all Neons, or that they go bad quickly. People run UOAs on 'em and I don't recall the majority of them having fuel dilution problems present.

 

i didnt say they where all bad, but 200k later im sure they dont last that long. i've noticed a big gain in MPG. so the fuel went somewhere... no rich code either.

 

The only way you are gaining MPG with a new FPR is if your old one was malfunctioning. What I was getting at is it is not a part that you replace just because you reached so many thousands of miles on the car.

 

Question, how is a fuel pressure regulator delivering fuel into the engine? That is the job of the injectors.

Piston slap is caused by a sloppy piston/cylinder tolerance..

It is possible that your FPR could over fuel the engine, but the PCM would most likely compensate by decreasing the pulse width of the injectors. Or your FPR could leak down pressure which might cause a long crank/hard start..

 

aperantly my old FPR wasnt letting fuel back into the tank and was going somewhere else. also if a FPR leaks your oil will smell of gas and become deluted( hints the no more piston slap) it will leak past the injectors when the car is off. it is also your filter ( FPR) the PCM would increase air to the engine and your MPG will suffer. you guys dont have to believe me. its kool. I know my car very well.

 

The engine is more likely to spray less gas in there than adding more air.
But I think you are right about your engine is consuming too much gas. With that much line pressure, the injectors can't adjust themselves enough.
Plus, it can flood your cylinders when the engine is off (High pressure + leaky injectors).
Thanks for sharing. It reminded me of what I learned from the past.

 

my idle is a liltle better too. im running 2000 dodge neon injectors 43 psi - 54 psi on my 2002 dodge neon. they are black in color. they are at 11.5 ohms. the FPR i bought is for a 2002 dodge neon rated at 54 psi. Our fuel line has a pulsation dampaner before it reaches the fuel rail. (haynes).

 

Are 2000 injectors and 2002 injectors the same?

 

That is not what causes piston slap for goodness sake!!!
Yeah, that is a rich condition. Nothing new and nothing specific to FPRs.
It's not that we don't believe that your FPR was bad. It's that you are saying things that are not true and incorrect. The point of threads like these are to obtain information to help yourself and others who visit the forum. That being said, only correct information is helpful and useful.
Since you know your car, you know that the proper fuel pressure is 53-63psi. You put injectors on your car that are rated 44-54psi (yes, 44psi is the correct min. psi for a 2000; not 43psi). That is just about the minimum your engine is supposed to have and you wonder why you are having fuel system related problems...