Anyone have a pretty good understanding of how the HPFP pressurizes? I recently got my car back together with all new parts(mainly a new head with new valvetrain) and Im getting absolutely NO pressure.

Before anyone asks this stupid question: YES the cam roller(piston) is in there and moves freely and has oil. The pump bolts up fine and compresses the spring and rod like it should.

Heres the thing, I am getting no ticking whatsoever. So, Im thinking the regulatoer inside the pump is bad or maybe the wire harness connector is bad and is not powering the pump. I have not tested the harness to see if it has a signal or not yet as I wanted to get this thread up and get your ideas.

Thanks for taking a look and offering up any ideas you may have.

 

Is the in tank fuel pump running to get fuel up to prime the HPFP?

 

Yeah its working. I can hear it prime up like it always does and is running while the car is on. I finally read the code, its the HPFP Fuel Rail Pressure sensor circuit high voltage which tells me that its not getting a signal from the HPFP. So either the pump dieded on me or my wiring harness went bad....I wish it was the harness LOL Ill have to test it with a volt meter.

 

HP Pressure sensor in the rail may have **** the bed thinking it is over pressure, not letting the pump build any more. The HP fuel sensor controls the pump, not the other way around. See if the connector on the fuel rail sensor is shorted or not fully seated. Ckt high voltage usually means it's shorted to the supply or an open ground. I sold my shop manual so I can't look at the wiring diagram.

 

Lol, you better hope its not the harness. It'll be a bitch trying to track those wires down if something is wrong with them. I'd much rather front out money for a new fuel pump than hunt them down unless the damage is right at the connector.

 

to track down the lines and test each of the lines is PITA - trust me - it took me over an 1.5 to test all of the terminals with a VOM.. from the fuel tank to hpfp then to the ecm..

here's the link for a new HPFP.. fuelpumpwholesale.com

good luck

 

Just saw this thread.

I Am Broke was correct. After Cubaniche did a log it showed that it was at like 20,000kpa at idle or something ridiculous. That said that there was probably a problem with either the sensor or the wiring and it was probably causing the ECU to be like "Forget that, I'm not sending anymore fuel into that rail!" lol He swapped the fuel rail pressure sensor with an old one and everything was good to go!

 

Yes. Sorry for the delay. Havent had a chance to update.
IamBroke hit the nail on the head. The sensor on the new rail was slightly bent off the metal fitting it is attached to which leads me to believe that the solder points inside may have been broken thus rendering the sensor null. I think this may have happened during shipping and I just didnt see it when I put it on. In any case, I pulled the old one off the old rail and installed it on the new one and VOILA! It worked like a charm! The car runs so smoothe now that I replaced the head and all the oil actuated components

Thanks all for the suggestions and your time commenting in this thread. It was much appreciated!

 

Even an old stopped clock (like me) is correct twice a day....glad my input helped a bit.

 

Iam Broke -

I wonder, is it possible the sensor is failing b/c of the tune is commanding a larger fuel increase or b/c large lobe cam?

 

For sure! LOL thanks again for the input sir!

In my case, the sensor was brand spankin' new on a new rail, new harness, new injectors. But it looked like this:



I hadnt noticed it when I put the rail on the car. I assume it got damaged during shipping as that corner was right up against the box corner and looked banged up. I think inside of that is the sensor that is probably soldered into the harness. So, I figure the bend like that broke the connection inside cause no matter how hard I push it back so it look sflush, it just pops back up to what it looks like now.

Luckily, the dang thing screwed out of the rail fairly easy and I was able to replace it with the one off the old rail Car drives like it hasnt in a long long time. Damn me and those supertechs! LOL

 

did you contact the company that sold you the rail? to get come sort of credit or refund?

 

Right?


A bunch have been getting damaged by UPS...

 

gotta love UPS..

 

LOL I guess I could...I just left it alone since I didnt bring it to his attention right away cause I didnt catch the damage until it was on the car throwing codes.

 

Yeah, after messing up a set of retros and possibly a pan on a transmission, they haven't been on my good side recently.

 

Not likely, the HPFP only creates the pressure commanded in the tune. The cam lobe mods are for more fuel volume.