[Dave W.]

Originally Posted by cwarren

pats just started having a similar problem car idles mid 80's will jump to 100 and bounce around at wot . fuel trims look fine too just as a fyi this is completely stock lpfp

Do you have a inline pump, too? Or just a stock lpfp alone?
Are you running a piggyback or just the cobb?

[cwarren]

stock lpfp and cobb only ran the car today and at idle it was 72 again and bouncing from high 50's all the way up to 100 not sure seems to be e85 related when i went stock a few weeks back it seemed fine for the most part .keep thinking i just need a new lpfp or install the inline been waiting on steves set up or i think it was tundra making one with the 455 not sure what to do yet but the car seems fine other than random high idle 800 rpm .

[135Pats]

Well Steve's inline pump was swapped in last night for the FFTEC pump...absolutely zero difference. Actually, now it's a bit worse, as the car pegs high 80s PSI under all but light load. Driving around under light load fuel pressure is perfect, 72PSI flat. But give it some load and the car loses all ability to regulate it. At this point there are only 2 parts in the fueling system left to replace, the filter/pressure regulator, and the EKP module or whatever that thing is. I am at a total loss, it's clearly not the pump as swapping made no change there. I hate my car right now.

Edit: I should add, Steve's pump is really well put together. Install couldn't have been easier.

[Ingeniator]

Originally Posted by 135Pats

Well Steve's inline pump was swapped in last night for the FFTEC pump...absolutely zero difference. Actually, now it's a bit worse, as the car pegs high 80s PSI under all but light load. Driving around under light load fuel pressure is perfect, 72PSI flat. But give it some load and the car loses all ability to regulate it. At this point there are only 2 parts in the fueling system left to replace, the filter/pressure regulator, and the EKP module or whatever that thing is. I am at a total loss, it's clearly not the pump as swapping made no change there. I hate my car right now.

Edit: I should add, Steve's pump is really well put together. Install couldn't have been easier.

Check voltage regulation. if that seems to work. Pull the regulator filter to inspect. Bet on 1 and buy replacement. If that doesn't work double down and at least you have a brand new fuel system.

[135Pats]

Originally Posted by Ingeniator

Check voltage regulation. if that seems to work. Pull the regulator filter to inspect. Bet on 1 and buy replacement. If that doesn't work double down and at least you have a brand new fuel system.

Yea at this point it can't be anything else that I can think of. I'll check the regulator first, shouldn't be too bad to get to and the part is cheap.

[Tony@vargasturbotech]

Can I ask you again why you are worried about this. I purposely run my lpfp at 80+ psi at idle as that's where I want it, all that fuel pressure means if what the HPFP is seeing and can use. It has nothing to do with that your engine is seeing. If you really really want it back to 72 I said in a bunch of posts back that's it prob the fuel controller in the kick panel, that controls your PWM.

[135Pats]

Originally Posted by Vargasturbotech

Can I ask you again why you are worried about this. I purposely run my lpfp at 80+ psi at idle as that's where I want it, all that fuel pressure means if what the HPFP is seeing and can use. It has nothing to do with that your engine is seeing. If you really really want it back to 72 I said in a bunch of posts back that's it prob the fuel controller in the kick panel, that controls your PWM.

I only care because the car has smoked 3 fuses in 5 weeks. If the 25 amp that is now in holds that's great, and if 85PSI is OK, even better. It's just an outlier from what i've seen with other setups, so that combined with having the car abruptly cut fuel, concerns me a bit.

[rob1024]

Originally Posted by 135Pats

The latter idea is very smart...but somewhat terrifying. Would really need to be careful.

Thanks for the part number that is extremely helpful. I still think that fundamentally, this is an issue with the pump and not the peripheral parts. So my next step is going to be to swap in SteveAZ's 255 setup and see how the car likes it.

When all is said and done, i'll be nearly $2K dumped into the damn car just to run E60. That sucks but it's a sunk cost.

That sucks man. I just went from 255 inline back to try a new stock pump only and it holds nicely 60-65psi under WOT running e60 mix. When it gets tired I will throw the 255 back in.
It could be that new stock pumps got upgraded now. BTW I am fbo with meth running 15deg monster Wedge flash. And new stock pump from ECS tunning runs great.

[135Pats]

Originally Posted by rob1024

That sucks man. I just went from 255 inline back to try a new stock pump only and it holds nicely 60-65psi under WOT running e60 mix. When it gets tired I will throw the 255 back in.
It could be that new stock pumps got upgraded now. BTW I am fbo with meth running 15deg monster Wedge flash. And new stock pump from ECS tunning runs great.

I swapped to a 25 amp months ago and all has been well. A big assist to Steve, obviously.

Now just need to get the high pressure side to stop nosediving down low. Tonys HPFP cant come soon enough!

[AWDBooSTIn90]

So you put in the bigger 25a fuse and now its not blowing the fuse anymore?

[UMich_335i]

I've been running this setup for almost a month now and have the same mindset as Tony. However since you said yours started happening a month in I'll be on the lookout, where is this fuse at again?

Also Andrew, just got an e50 tune done by Jake and wow, I know what you meant after your test drive with him earlier this year.

[135Pats]

Originally Posted by AWDBooSTIn90

So you put in the bigger 25a fuse and now its not blowing the fuse anymore?

Yep. Very, very simple fix once I got to the root of the problem. I replaced literally the entire fuel system outside of the rails and fuel lines before realizing the fuse was the root problem. Cost me $5 bucks to fix at that point.

Originally Posted by UMich_335i

I've been running this setup for almost a month now and have the same mindset as Tony. However since you said yours started happening a month in I'll be on the lookout, where is this fuse at again?

Also Andrew, just got an e50 tune done by Jake and wow, I know what you meant after your test drive with him earlier this year.

If you are drawing too many amps, you'll know pretty fast. The 20 amp would blow within a week or two of driving, over and over.

You should be fine, for whatever reason my car wanted to pull justttt over 20 amps.

And nice! Yea it's completely different once you get some octane in the mix. Stock frames are hungry for it.

[UMich_335i]

Here are my logs for comparison:
http://datazap.me/u/umich335i/140917...=0&data=2-3-14

[shushikiary]

My kit from SteveAZ was doing the same thing, about 83 PSI constant except under load until I replaced the fuel filter in the driver side of the tank which also replaced the pressure regulator, and blowing out the entire fuel tank vent system and hose clamping the connector that connects to the LPFP top hat (the black vent hose that connects to the elbow that has the nasty clip on it), then my fuel pressures went back to around 70 PSI and down into the low 60's heavy under load (E35 mix on E30 cobb map) (which first made me think both the pumps were not working, so I double checked that and they indeed are both working).

Here's the part number for what I replaced: 16117163295 (note there is a second part number for this "kit" as well: 16147163296, but that kit is for LCI cars, the one ending in 5 is for pre-LCI cars)

[ferocity02]

Bump! Having an identical issue with Fuel-It Stage 2 LPFP. Pressure is a cool 72-73psi all the time, then after I go WOT it is a constant 84-85psi until restart. LPFP sensor is new.

Thinking of upping the fuse size (not sure how this would play into fuel pressure) and/or replacing the filter/regulator assembly on the driver's side of the tank.

[damonp335i]

Originally Posted by ferocity02

Bump! Having an identical issue with Fuel-It Stage 2 LPFP. Pressure is a cool 72-73psi all the time, then after I go WOT it is a constant 84-85psi until restart. LPFP sensor is new.

Thinking of upping the fuse size (not sure how this would play into fuel pressure) and/or replacing the filter/regulator assembly on the driver's side of the tank.

Same thing happening to me.. Just started a thread about this. I've read this whole thread twice sofar.. It seems as if a 25a fuse worked for some and replacing the fuel filter and FPR worked for others.. Guess I'll try both..

[135Pats]

Originally Posted by ferocity02

Bump! Having an identical issue with Fuel-It Stage 2 LPFP. Pressure is a cool 72-73psi all the time, then after I go WOT it is a constant 84-85psi until restart. LPFP sensor is new.

Thinking of upping the fuse size (not sure how this would play into fuel pressure) and/or replacing the filter/regulator assembly on the driver's side of the tank.

Just saw your PM; responding now.

Originally Posted by damonp335i

Same thing happening to me.. Just started a thread about this. I've read this whole thread twice sofar.. It seems as if a 25a fuse worked for some and replacing the fuel filter and FPR worked for others.. Guess I'll try both..

To be clear; replacing the fuse didn't change anything with regards to fuel pressure. It was an important fix for me, but was done independently of fuel pressure matters.

[damonp335i]

Originally Posted by 135Pats

Just saw your PM; responding now.

To be clear; replacing the fuse didn't change anything with regards to fuel pressure. It was an important fix for me, but was done independently of fuel pressure matters.

So what exactly did you change to notice the difference?

[135Pats]

Originally Posted by damonp335i

So what exactly did you change to notice the difference?

I didn't change anything. The car is running as a deadhead setup right now with twin walbros on the low pressure side. It runs 80+ PSI at idle.

No issues.

[iqraceworks]

Originally Posted by ferocity02

Bump! Having an identical issue with Fuel-It Stage 2 LPFP. Pressure is a cool 72-73psi all the time, then after I go WOT it is a constant 84-85psi until restart. LPFP sensor is new.

Thinking of upping the fuse size (not sure how this would play into fuel pressure) and/or replacing the filter/regulator assembly on the driver's side of the tank.

I know it's an old thread....but I'm having the identical issues after installing my new stage 2 Walbro 450 LPFP. 72psi at idle and light driving......after a pull, it then stays at a constant 82-83psi. If I restart the car....back down to 72psi.

The car runs great, no issues, no blown fuses.......

Do I need to worry about this at all? From the searching I've done....this is very common. I open some old logs from when I had the stock LPFP....and it did the same thing.

[sbsk518]

Originally Posted by iqraceworks

I know it's an old thread....but I'm having the identical issues after installing my new stage 2 Walbro 450 LPFP. 72psi at idle and light driving......after a pull, it then stays at a constant 82-83psi. If I restart the car....back down to 72psi.

The car runs great, no issues, no blown fuses.......

Do I need to worry about this at all? From the searching I've done....this is very common. I open some old logs from when I had the stock LPFP....and it did the same thing.

I've installed the same pump about a year ago and see similar psi values. Never had an issue with it so far.

[_N54]

My low pressure does dip to the 80's also at certain occasions and even 90 psi for a split second when I shift to the next gear. I think its normal to be honest. It's just a healthy strong pump working and getting regulated back to normal pressures. My log also shows 80 psi when I'm driving normal. I'm running the BMP Stage 2 bucket-less.

https://datazap.me/u/n54tt/mhd-stage...0&data=3-11-20