Fuel rail pressure for 2007 115 rwd

[Craigemm123]

Hi all
I've just joined the site so this is my first post / question.

I have a 115 t350 2007 rwd and have a starting issue, does anyone know the correct PSI I should be getting for the fuel delivered to the rail as mine is fluctuating by nearly 1000 on tick over?

[knobby1]

Hi all
I've just joined the site so this is my first post / question.

I have a 115 t350 2007 rwd and have a starting issue, does anyone know the correct PSI I should be getting for the fuel delivered to the rail as mine is fluctuating by nearly 1000 on tick over?

What are you reading the pressure with??

Idle rail pressures are usually up in the ~30,000kpa, (~4350psi) region. This will climb dramatically as engine rpm and load increases and can be upwards of 200,000kpa (~29,000psi)..

If you're pressures are fluctuating dramatically, I'd suspect you SCV may be playing up.

Lord Knobrot

[Frag]

Should be 230 bar at idle...
With no faults it won't vary very much at all,
+/- 30 bar max,about acceptable.

[daraioj]

Should be 230 bar at idle...
With no faults it won't vary very much at all,
+/- 30 bar max,about acceptable.

Hey all, my 100ps mk7 idles at 500bar and doesn't vary much when accelerating. It passed a pump learn and pilot learn first go. No error codes and works fine.
I know this may sound like a very stupid question but I also know that fuel pressure issues can end up being very expensive if not looked after, so is it something I should be worried about? Anything I should check?

Thanks in advance

[Frag]

What are you using to measure that pressure with ?
That's nowhere near right,but if that's the case,also it wouldn't pass pump or injector learns....

[daraioj]

What are you using to measure that pressure with ?
That's nowhere near right,but if that's the case,also it wouldn't pass pump or injector learns....

I'm using Forscan. It shows 48000 to 50000 kpa

[daraioj]

I'll give the learns another go, I did them a couple of months ago. In any case shouldn't I be getting some full pressure related codes?

[Craigemm123]

I’m using a laser 5091 which I’ve had for years but does the basics, I suspected the SCV but local garages keep saying injectors ! I’ve already paid for 2 to be changed but that obviously isn’t the issue and as one of you said the re learns failed when they changed these so I’m fixing myself now.

[daraioj]

Is there anything else that could be causing pressure issues (other than the SCV)?

Seems like mine can't match the desired pressure when it drops below 500 bar.

Is that enough to say the SCV needs replacing or is there anything else I can test?

[v8dave]

Looks like the scv not functioning correctly.

The scv mechanically defaults to open.
The pcm closes it to limit fuel pressure.

As you fuel pressure is high at idle it looks like the scv is not closing, this could be a mechanically jammed scv or an electrical issue.

[daraioj]

Looks like the scv not functioning correctly.

The scv mechanically defaults to open.
The pcm closes it to limit fuel pressure.

As you fuel pressure is high at idle it looks like the scv is not closing, this could be a mechanically jammed scv or an electrical issue.

Thanks for that info!

Today I used torque and another ELM adapter to log a 30ish km drive. Pressure fluctuated between 500 bar at idle and 1600 at full load.
Then I did a pump learn expecting it to fail. Just to confirm my SCV was gone but... It completed successfully first go. (Did a pilot learn while I was at it)

Now it's idling at 230. I'll log another run and see how high it goes.

I don't get it though, the last pump learn was done 5000km ago. Am I missing something?

Also, if the comments above are correct and PRV's blow at 1600bar then I'm in trouble. What would be the symptoms?

[grogan197]

Normal operating pressure is up to 1600 bar so the PRV won't go until over that, not sure what the limit is though. If the PRV blows then you'll have a check engine light on the dash.

[daraioj]

Normal operating pressure is up to 1600 bar so the PRV won't go until over that, not sure what the limit is though. If the PRV blows then you'll have a check engine light on the dash.

Perfect! Thanks a lot for that info