Fuel pressure

[GRM]

I did search online for normal parameters for a high pressure fuel pump (stock) but the numbers seem to be all over the map.
My 2015 GTI shows 20 psi for the low pressure pump and about 70 psi for the high pressure pump at idle. It goes up to 360 psi at around 3k rotations. What numbers should I expect from a third party HPFP?
Thanks.

 

[Diggs24]

You can't see the low pressure pump, that's some modeled number. HPFP on a 2.0 runs 200bar at WOT.

 

[GRM]

200 bar is about 3000 psi. Could you recommend a good, relatively cheap high pressure pump? I run stage 2. Thanks

 

[Diggs24]

No.

 

[GRM]

No.

Ok. Thanks anyway.

 

[JerseyDrew77]

200 bar is about 3000 psi. Could you recommend a good, relatively cheap high pressure pump? I run stage 2. Thanks

The reason why Diggs said no was because he won't recommend a cheap HPFP and why would you even want to use a cheap HPFP in the first place? Your best bet is to get the Autotech HPFP internal kit.

 

[GRM]

My bad. I should’ve mention what relatively cheap means to me. Im looking for something around $400-500 top. I see some at $350-400 but I’m not sure how good they are.

 

[Diggs24]

What are you trying to solve? HPFP is a poor upgrade regardless.

 

[GRM]

What are you trying to solve? HPFP is a poor upgrade regardless.

Sometimes I have to crank it a couple times to get it started. I know it is not the low pressure pump because that was changed about 15k miles ago by the previous owner. I also have new spark plugs. The only part I could think about was the HPFP.

 

[edsonmassao]

Sometimes I have to crank it a couple times to get it started.

Couldn't it be some injector issues?

 

[Superfreak]

Sometimes I have to crank it a couple times to get it started. I know it is not the low pressure pump because that was changed about 15k miles ago by the previous owner. I also have new spark plugs. The only part I could think about was the HPFP.

Are you on an ethanol tune? I’ve heard that some people have a hard time starting when tuned on E. Is this happening on either cold or hot starts? Do you have a tuner to reach out to?

 

[GIACUser]

If it is a fuel pump issue, most often problem in 2.0t motor is low pressure fuel pump. After the car sits overnight or for a while it loses all of its fuel pressure,
LPFP normally primes (runs) when you open the drivers door to pressurise system for starting. If that is not occurring it will crank a bit before starting because there is no pressure in the system yet.

Get in car, turn key to on position without starting engine (this should prime the pump , wait about 15 sec, then try and start car. If it starts right up you have somewhere to start looking.

In any event, the car started normally, then it didn't. Goal is to find out what changed and the solution isn't going to be found in an upgraded aftermarket HPFP. The HPFP is operated by the lobe on the camshaft so it really does not come to pressure until car starts. The pressure necessary to start the car comes from the electric pump in the tank. Car should start fine with OEM parts when everything is working properly.

If LPFP is priming, next couple of things to check would be fuel filter, is battery status, and of course starter.

Good luck.

 

[Diggs24]

Your older posts say it's Unitronic Stage 2 so you can't upgrade the HPFP anyways.

 

[EpicTech]

My car was Uni stage 2 for 80k miles, now is Uni Stage 2+. I never had a starting problem, ever. HPFP is not going to correct your issue. I would question things like injectors and/or harness/connectors/grounds. Sparkplugs and their gap. The LPFP and associated wiring/controller. Clogged fuel lines and/or trash in fuel lines. You can also try flashing the car back to stock, and see if the problem persists without the tune applied, but that is sort of a why not step. Since your problem exists in the realm of initial start up, I would be more inclined to check the things I mention, as they are key in whether or not the car can start. Curious, but how does the car sound when it is cranking? Is it normal speed/turning over, or is it slower? I ask for a reason.

 

[EpicTech]

Side note - I once bought a "blown engine" V8 Thunderbird (the bodystyle similar to the cougar) Owner said $500 bucks because needs motor, the rest of the car was really good shape. I get the car home, and about 30 minutes later after checking the usual bs of things involved with getting a car to start, I pull the fuel filter and find trash blocking the inlet from the tank. A new filter later and clearing the fuel line, I go and bump the key and she fires right up.