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Volvo 850 power loss under hard acceleration Topic is solved

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

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Sommerfeldt
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Re: Volvo 850 power loss under hard acceleration

Post by Sommerfeldt »

Well, it doesn't quite work like that, misha. You need a system. Are you asking me about a head curve or something? I know the operating pressure and the flow as Bosch supplies it for the application we're talking about, which is what I told you. 300 KPA/120 liters/hr.

- S
Last edited by Sommerfeldt on 29 Jan 2019, 11:49, edited 1 time in total.
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[Gone] '96 855 T5 - R bumper and spoiler, Koni Yellows & blue H&R springs all 'round.
[Sold] '97 S70 T5
[Gone] '95 855 T5-R - one of the black ones... sadly stolen and wrecked.

Jaumme
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Post by Jaumme »

I recorded a video for you yo see what is going on here

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misha
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Post by misha »

I know what i asked you...and i know exactly how it works....question is do you know?

Fuel pump is making pressure upon restriction of fpr.
If you stick it in a jar of fuel there will be a slow steady flow....just like from tap when it's 50% opened...no squirting or pressure or something like that.It is capable to make and to push 3 bar pressure but that pressure can't be achieved without fpr in the line.

I experimented once with this while making injector cleaner/tester for my own purposes and i know exactly what i'm talking about.

The same way acts a high pressure washer of ...let's say 150bar.
Restriction is dictating a pressure.If you remove the nozzle or the hose for pressure gun...the flow from pressure washer would be just like it is from a water supply....a tap.
'97 850 2.5 20v / fully equipped / Motronic 4.4 from the factory / upgraded with S,V,C,XC70 instrument cluster / polar white wagon
History of Volvos in the family:
'71 144 S
'73 144 De Luxe
'78 244 DL
'78 244 DL
'79 244 GLE
'85 340 GLS

Sommerfeldt
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Post by Sommerfeldt »

misha wrote: 29 Jan 2019, 11:51 I know what i asked you...and i know exactly how it works....question is do you know?

Fuel pump is making pressure upon restriction of fpr.
If you stick it in a jar of fuel there will be a slow steady flow....just like from tap when it's 50% opened...no squirting or pressure or something like that.It is capable to make and to push 3 bar pressure but that pressure can't be achieved without fpr in the line.

I experimented once with this while making injector cleaner/tester for my own purposes and i know exactly what i'm talking about.

The same way acts a high pressure washer of ...let's say 150bar.
Restriction is dictating a pressure.If you remove the nozzle or the hose for pressure gun...the flow from pressure washer would be just like it is from a water supply....a tap.
Well... that's exactly why your question made no sense, and you got no answer to it, right? Which is why I said it'll deliver 120 liters per hour out of your jar. You can call that a slow flow or a spray or a drizzle or whatever you want - it'll be 120 liters per hour. And if you know "exactly what you're talking about", then that was just a bit of a sad attempt at trapping me - which didn't work at all. I think my answer also shows that I know what I'm talking about, which makes your "explanation" of it even sadder than the "clever" "trap".

So, do you want that head curve, or are you done talking about pressure washers and sad traps, so maybe we can see what that power loss is about?

- S
2018 S90 T8 Inscription - glossy black with amber interior and dark as night rear windows.
[Gone] '96 855 T5 - R bumper and spoiler, Koni Yellows & blue H&R springs all 'round.
[Sold] '97 S70 T5
[Gone] '95 855 T5-R - one of the black ones... sadly stolen and wrecked.

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Post by Sommerfeldt »

Jaumme wrote: 29 Jan 2019, 11:44 I recorded a video for you yo see what is going on here
The increase is a little weird, but your numbers seem okay but low-ish, also with that long hose and whatnot. I can't quite catch what's going on with the routing - are you able to drive with that thing connected, and video it when the power loss happens, so we can see what it does, if anything?

- S
2018 S90 T8 Inscription - glossy black with amber interior and dark as night rear windows.
[Gone] '96 855 T5 - R bumper and spoiler, Koni Yellows & blue H&R springs all 'round.
[Sold] '97 S70 T5
[Gone] '95 855 T5-R - one of the black ones... sadly stolen and wrecked.

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Post by Jaumme »

i definetly cant video that while driving alone but what happens is the pressure is just going down as engine rpm goes up, at 5k rpm the pressure is about 2 bar

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Post by Sommerfeldt »

misha wrote: 29 Jan 2019, 12:22 You have issues.
What trap you're talking about?
I just asked you a simple question about pressure....which you didn't had an answer to....not about l/hour flow. :roll:
If i asked you about photography you might knew the answer.
Pressure washer was just an example to give you a hint to understand how system works.
I don't believe what you're saying.....a trap. :lol:

I know what i'm saying or claiming based on my experience and i know exactly what i'm talking about.
There was no answer to the question you posed, and if you "know exactly what you're talking about", you should know that. If you don't, then you don't know what you're talking about at all. I still explained it to you. I even asked you to clarify if you meant you wanted a head curve (google it, smart guy - maybe you'll learn something your "experiments" didn't tell you).

And you say I have issues, Stalker Bob? :roll: If you ask me about photography, I will most definitely know the answer, but your stalking is neither here nor there, and this isn't a photography forum.

- S
2018 S90 T8 Inscription - glossy black with amber interior and dark as night rear windows.
[Gone] '96 855 T5 - R bumper and spoiler, Koni Yellows & blue H&R springs all 'round.
[Sold] '97 S70 T5
[Gone] '95 855 T5-R - one of the black ones... sadly stolen and wrecked.

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Post by Sommerfeldt »

Jaumme wrote: 29 Jan 2019, 12:45 i definetly cant video that while driving alone but what happens is the pressure is just going down as engine rpm goes up, at 5k rpm the pressure is about 2 bar
Hm. I thought you said it cut power suddenly?

- S
2018 S90 T8 Inscription - glossy black with amber interior and dark as night rear windows.
[Gone] '96 855 T5 - R bumper and spoiler, Koni Yellows & blue H&R springs all 'round.
[Sold] '97 S70 T5
[Gone] '95 855 T5-R - one of the black ones... sadly stolen and wrecked.

Jaumme
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Post by Jaumme »

Sommerfeldt wrote: 29 Jan 2019, 12:56
Jaumme wrote: 29 Jan 2019, 12:45 i definetly cant video that while driving alone but what happens is the pressure is just going down as engine rpm goes up, at 5k rpm the pressure is about 2 bar
Hm. I thought you said it cut power suddenly?

- S
yes the power has a clean cut but not the presure

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Post by Sommerfeldt »

Jaumme wrote: 29 Jan 2019, 13:08 yes the power has a clean cut but not the presure
Okay. It might be that you're simply hitting a lower limit, to where fuel flow is simply too low to meet the load demand that the ECU is seeing. Did you do the pressure testing from the PDF image that misha posted earlier?

- S
2018 S90 T8 Inscription - glossy black with amber interior and dark as night rear windows.
[Gone] '96 855 T5 - R bumper and spoiler, Koni Yellows & blue H&R springs all 'round.
[Sold] '97 S70 T5
[Gone] '95 855 T5-R - one of the black ones... sadly stolen and wrecked.

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