|
|
|
|
|
|
BMW Garage | BMW Meets | Register | Search | Today's Posts | Mark Forums Read |
|
BMW 3-Series (E90 E92) Forum
>
What's your Lpfp pressure in your N54 at idle? Trying to figure this out
|
|
06-18-2015, 06:27 AM | #1 |
g35x
104
Rep 630
Posts |
What's your Lpfp pressure in your N54 at idle? Trying to figure this out
I am trying to figure out if 67 psi at idle is low for a stock pump? I'm looking to replace it with a stock one and upgrade later as this car has cost me way to much since I bought it a month ago. When running barely a 30% e85 mixture I get sudden dips of in the 40's for pressure WOT. I have found a 95 dollar oem pump assembly so that's not bad. Car handles 93 octane all day with DCI map 5 or map 1 no pressure problems. When I get 40's I loose tons of boost and sometimes get a misfire on cylinder 4 probably due to not enough fuel. I would be happy running 30% e85 because it hits hard for a good 5 seconds lol until pressure drops. I know this is somewhat simular to my last post but I'm just wondering what others get for pressure who knows maybe my LP sensor is going out as readings fluctuate a bit and the cylinder 4 misfire is from something else . It's all good on stock settings so no warranty coverage on this would be nice tho. Just gathering some more info before I pull the trigger on my options.
|
06-18-2015, 08:02 AM | #3 |
Brigadier General
1550
Rep 3,475
Posts
Drives: E90 6MT FBO; '18 F150 Platinum
Join Date: Jul 2013
Location: WI
|
Might as well just get the upgraded walboro for like $100 more... You can run 100% E85 on it. The stock fuel system isn't made for E85 anyways.
__________________
2008 335xi 6MT | VRSF Catless DP | VRSF 7" FMIC | VRSF CP | TIAL BOV | DCI | MHD 2+ BC Racing BR | Stoptech 600 | Firehawk Indy 500 255 Square | Atric Altimax 225 Sq. 2018 F-150 Platinum 701A | FX4 | 3.5 EcoBeast Last edited by Antetokounmpo; 06-18-2015 at 08:23 AM.. |
Appreciate
1
Nardoninety166.00 |
06-18-2015, 08:49 AM | #4 |
Banned
2134
Rep 3,555
Posts |
Your LPFP cant handle e30. Idle pressure doesnt really matter since you are dropping below 50 at WOT.
Get the stage 2. At idle my oem was at 67, and at wot with e40 it was between 60-70. My stage 2 is at 67 at idle and stays around 67 with E70 |
Appreciate
1
mweisdorfer1900.00 |
06-18-2015, 09:02 AM | #5 |
Colonel
533
Rep 2,872
Posts |
Every cars stock LPFP is slightly different. Some can handle E40, like mine does, and some go haywire over 20% E85, but in reality anything over E40 should be paired with an upgraded LPFP anyway, and a backend flash.
|
Appreciate
0
|
06-18-2015, 09:07 AM | #6 | |
Banned
2134
Rep 3,555
Posts |
Quote:
Im saying his cant handle e30. He made another thread about this yesterday. |
|
Appreciate
0
|
06-18-2015, 09:09 AM | #7 |
Major General
456
Rep 6,478
Posts |
DME targets 72.5PSI flat regardless of load applied.
__________________
E88 N54 Alpinweiss/Coral Red/Motiv HTA 3586r Tial .82AR/Other stuff...652WHP
F30 N55 XDrive EBII |
Appreciate
0
|
08-02-2020, 05:27 PM | #8 |
Brigadier General
1981
Rep 3,715
Posts |
I know it's an old thread....but I've got a question about LPFP pressure at idle.
Just did a new stage 2 LPFP install. When I fire up the car....it's right at 72psi. But as soon as I start driving the car and put a load on it.......the LPFP bumps up to around 85psi...and stays there until I shut the car off and restart it again. Is that normal? It's not causing any issues......just wondering if that's normal when running a Walbro 450 pump. |
Appreciate
0
|
08-02-2020, 07:14 PM | #9 |
Major General
1900
Rep 6,968
Posts
Drives: 2007 Black/Black 335i e90
Join Date: Apr 2011
Location: Holly, MI
|
82-83psi
Mines only a year old |
Appreciate
0
|
08-02-2020, 08:25 PM | #10 |
Brigadier General
1981
Rep 3,715
Posts |
I heard that the DME targets 72psi at idle ...which mine does. Then when you put a load on the motor, the new target jumps up to around 85psi.
Sounds like yours does the same....guess it's normal. |
Appreciate
0
|
08-03-2020, 11:35 AM | #12 | |
Brigadier General
1981
Rep 3,715
Posts |
Quote:
It runs fine.....would just like to know why it's doing that. |
|
Appreciate
0
|
08-04-2020, 01:54 PM | #13 |
Captain
449
Rep 823
Posts |
Mine likes to hang around 82 psi under no load and low load, but occasionally it's around 72 psi in the same conditions. I just went back and checked some logs from the stock LPFP and it did the same thing, so this discrepancy isn't unique to an upgraded pump.
So I don't know the reason, but it behaves the same as stock, so I'm not concerned.
__________________
2008 335xi 6MT - 16T China Turbskies - eBay FMIC, DP & CP - VRSF Inlets - SSR DCI's - Walbro 450 LPFP - RFP e85 Tune
|
Appreciate
0
|
08-04-2020, 02:12 PM | #14 | |
Brigadier General
1981
Rep 3,715
Posts |
Quote:
Also....I just checked an old log with my stock LPFP...... you're right, it did the same thing. Around 72psi before a pull.....And then would be up around 82psi after the pull. |
|
Appreciate
0
|
09-01-2020, 07:13 AM | #15 |
Registered
0
Rep 4
Posts |
I am also trying to figure this out. My high pressure values seem good. But my low pressure is miserable. At idle or light throttle is at 50-54 psi. On WOT comes down to 40 psi.
This is on a new Walbro 450 pump + new Lp sensor + new Hp sensor + cleaned and checked injectors. Any suggestions will immensely help me. I’m in the dark. |
Appreciate
0
|
09-01-2020, 07:24 AM | #16 |
Colonel
1209
Rep 2,476
Posts |
What lead you to replacing all of those parts? Were you having fuel pressure problems before and decided to upgrade the pump?
Last edited by Emilime75; 09-01-2020 at 07:35 AM.. |
Appreciate
0
|
09-01-2020, 11:29 PM | #17 | |
Registered
0
Rep 4
Posts |
Quote:
Once everything was changed, I am still getting 40-50 psi. So at the moment, I don’t know what exactly should be changed. |
|
Appreciate
0
|
09-02-2020, 04:53 AM | #19 |
Registered
0
Rep 4
Posts |
|
Appreciate
0
|
09-02-2020, 11:55 AM | #21 |
Registered
0
Rep 4
Posts |
|
Appreciate
0
|
Bookmarks |
Thread Tools | Search this Thread |
|
|