Long crank, no faults

[ftillier]

Upon starting, the rail pressure jumped pretty much immediately to that 14000kpa range - it did not take long at all. I don't hear the low pressure pump prime at all when I open the door. Given the tank is opposite from me, I'm not too surprised, but it does make me wonder if your pump is on its way out and making extra noise.

I did not see a reading for actual low pressure fuel pump pressure.

 

[Jimmy Brooks]

Upon starting, the rail pressure jumped pretty much immediately to that 14000kpa range - it did not take long at all. I don't hear the low pressure pump prime at all when I open the door. Given the tank is opposite from me, I'm not too surprised, but it does make me wonder if your pump is on its way out and making extra noise.

I did not see a reading for actual low pressure fuel pump pressure.

Is it jumping to 14000kpa while cranking or right after starting during high idol?

 

[Jimmy Brooks]

Upon starting, the rail pressure jumped pretty much immediately to that 14000kpa range - it did not take long at all. I don't hear the low pressure pump prime at all when I open the door. Given the tank is opposite from me, I'm not too surprised, but it does make me wonder if your pump is on its way out and making extra noise.

I did not see a reading for actual low pressure fuel pump pressure.

And as for hearing the low pressure prime, I only hear it if it’s extremely silent around me. Most of the time I don’t hear it tho

 

[ryanjl]

Just curious. When you have a long crank, do you have to hold down the start button or does pushing it just once initiate the sequence?

 

[ftillier]

Is it jumping to 14000kpa while cranking or right after starting during high idol?

I think it's jumping up quickly while cranking, however, having had the ignition on for a bit before cranking so I could log values, it fired up pretty much right away, much faster than when starting from the car being off.

 

[Jimmy Brooks]

Just curious. When you have a long crank, do you have to hold down the start button or does pushing it just once initiate the sequence?

Just have to push it once to initiate the sequence.

 

[Jimmy Brooks]

I think it's jumping up quickly while cranking, however, having had the ignition on for a bit before cranking so I could log values, it fired up pretty much right away, much faster than when starting from the car being off.

Interesting… yesterday I watched it crank and build pressure slowly to 2000psi during the first crank. Turned right over on the second one but the rpm went straight to 1500 rather then going up to 2000 rpm on start then doing the warm up idol 1500 rpm. Today I did a cold start after 5 hours of being turned off and the pressure built immediately while cranking and it fired up normal. So it seems like a lot of the time it’s having an issue building pressure in the rail on crank

 

[ftillier]

Next time you start cold, could you see if behavior changes if you turn the ignition on and wait, say 30 seconds, before starting the engine?

 

[jlglr4]

Checked mine again after sitting one day and got same results as last time - ignition on, before cranking, showed 650 kpa (95 psi). I’ll see if I can get a graph of the pressure increase on cranking. Maybe comparing graphs can give you some idea of the hpfp performance.

Also wondering if you can see the temp sensor voltages when the car is cold. Just thinking that a bad temp sensor might be telling the engine that it’s warmer than it actually is, giving the wrong air/fuel mixture. You might try to rule that out - and maybe change the fuel rail pressure sensor - before resorting to changing any fuel pumps. I remember someone saying the fuel rail pressure sensor is not too difficult to change out, but haven‘t done it myself. I think it’s at the firewall end of the passenger side fuel rail - not sure if you can reach from topside, or maybe go through passenger wheel well?

 

[Jimmy Brooks]

Next time you start cold, could you see if behavior changes if you turn the ignition on and wait, say 30 seconds, before starting the engine?

No difference, still did it.