[135Pats]

I’ll get straight to the point- the car is providing about 85PSI flat at idle on the low pressure side. Give it some sudden load and it spikes upwards of 100PSI. Obviously, I don’t want to see more than 72 or so flat WOT. The car is throwing the 2AAE fuel pump code but that appears to be a shadow, does not impact driving so far as I can tell. I know for a fact the install was done correctly, so I’m strongly inclined to think it is on the software side. Below is the rest of the relevant info that could be helpful. Have at it guys and gals, what am I missing here? How do I fix this?

Full Context:

LPFP is maybe a month old

FFTEC fuel pump is maybe a month old

Replaced HPFP yesterday (unrelated swap, but no effect)

Replaced LPFP sensor yesterday (old sensor was smoked but swapping only got me back to square one)

Currently running OTS E30 to keep things more modest as I sort this out. Had been running an E50 map, regardless PSI on the low pressure side was virtually identical. Could be a 3d scalar issue?

Have reset fuel adapatations with BT cable to no effect

[C.Pop]

Not a big deal. Happens sometimes. I wouldn't sweat it, at all.

[135Pats]

Originally Posted by C.Pop

Not a big deal. Happens sometimes. I wouldn't sweat it, at all.

It’s not something I’m terrified about, but ideally I don’t want to see it eclipsing 100PSI when requested is only 72 flat. I wonder if this is something that long term adaptations would sort out? I pulled a log last night but it was shortly after resetting adaptations so short term trims were all over the place. And of course, it snowed again today, so I can’t pull another log for a day or two.

[C.Pop]

1: What does your log show for low pressure fuel?
2: Cobb will display peak value; this is a transient value of very little importance. If you're running 100 psi and it's staying there the whole time, I still wouldn't be upset but I would agree something was amiss.

I think that very likely you're getting a spike between shifts or sudden off throttle and you're attributing far more meaning to this than you ought to. Really, don't worry about it.

Otherwise I suppose you could replace your fuel pressure regulator. I wouldn't.

[Bimmer305]

Fuel pressure regulator my guess.

[135Pats]

Originally Posted by C.Pop

1: What does your log show for low pressure fuel?
2: Cobb will display peak value; this is a transient value of very little importance. If you're running 100 psi and it's staying there the whole time, I still wouldn't be upset but I would agree something was amiss.

I think that very likely you're getting a spike between shifts or sudden off throttle and you're attributing far more meaning to this than you ought to. Really, don't worry about it.

Otherwise I suppose you could replace your fuel pressure regulator. I wouldn't.

Here is the log from last night. Since the DME has not had much time to re-adapt, the pegged short term trims are likely just a fluke, last log they didn’t budge from 0-2 or so. Also, disregard the horrendous timing flatline. But check the low pressure side and draw your own conclusions. It does seem to straighten out a bit in 4th and 5th, so perhaps the car needs more time to adapt. But I doubt that.

http://datazap.me/u/135pats/3-5?log=0&data=1-19

[135Pats]

Originally Posted by Bimmer305

Fuel pressure regulator my guess.

That was going to be my next guess. Interesting.

[WedgePerformance]

Give it a week to settle down. I had the same issue when I replaced my bucket and put my inline back in this past summer. @aubeast86 had the same issue. I tried resetting adaptation and even coded out the error, but kept getting the lift when I would shut the car off.

[SINGH_]

this is a little unrelated... but how were you able to log the psi rates? i have a procede installed, and can only seem to log pump voltage. also have a bt cable that i haven't put into use yet.

thanks

[135Pats]

Originally Posted by WedgePerformance

Give it a week to settle down. I had the same issue when I replaced my bucket and put my inline back in this past summer. @aubeast86 had the same issue. I tried resetting adaptation and even coded out the error, but kept getting the lift when I would shut the car off.

That is exactly what I’m dealing with. Only reason I notice it is because I log frequently and the lift sign when I pull the key fob. I guess I’ll wait a week and see if it calms down.

Originally Posted by E92 N54

this is a little unrelated... but how were you able to log the psi rates? i have a procede installed, and can only seem to log pump voltage. also have a bt cable that i haven't put into use yet.

thanks

Cobb logs it. BT cable does as well. No idea if PROcede has that as a channel.

[Bimmer305]

Originally Posted by E92 N54

.. i have a procede installed,....

thanks

That's your problem right there.

[Dmacc]

Does anyone know how to log lpfp psi with the OFT and its new data channels? I think I may have my channels set up incorrectly.

[SINGH_]

Originally Posted by Bimmer305

That's your problem right there.

Originally Posted by 135Pats

Cobb logs it. BT cable does as well. No idea if PROcede has that as a channel.

thanks! i haven't had the time to use it, i'll take a crack at it tomorrow... as well as doing a dme flash.

[Tony@vargasturbotech]

Don't worry about it. The car regulates fuel pressure via voltage and ours seemed to do this from time to time as well. It cant any more as both pumps are being fed 12+ volts at all times and the its being regulated by a real regulator.

Edit: Pumps ARE being fed 12 Volts all the time, I had put are not originally.

[135Pats]

Originally Posted by Vargasturbotech

Don't worry about it. The car regulates fuel pressure via voltage and ours seemed to do this from time to time as well. It cant any more as both pumps are not being fed 12+ volts at all times and the its being regulated by a real regulator.

Thanks for the input, Tony.

Interesting, so my LPFP bucket blew a fuse in it over the weekend, which is what led me to say screw it and replace the HPFP as well while the car was on the rack. The LPFP is literally a month old, so I’m curious as to why the fuse blew. I was at near idle when it happened so it’s not like the system was under a ton of load and duty cycle. Perhaps the voltage feed spiked too much? I plead near complete ignorance when it comes to electronics, so I am in the dark here.

But it sounds like the increased fuel pressure in and of itself is not something to worry about. So that’s good to know.

[Tony@vargasturbotech]

Originally Posted by 135Pats

Thanks for the input, Tony.

Interesting, so my LPFP bucket blew a fuse in it over the weekend, which is what led me to say screw it and replace the HPFP as well while the car was on the rack. The LPFP is literally a month old, so I’m curious as to why the fuse blew. I was at near idle when it happened so it’s not like the system was under a ton of load and duty cycle. Perhaps the voltage feed spiked too much? I plead near complete ignorance when it comes to electronics, so I am in the dark here.

But it sounds like the increased fuel pressure in and of itself is not something to worry about. So that’s good to know.

If you have replaced your LPFP and are blowing fuses, check over all your wiring carefully. I also went up 1-2 fuse sizes when running the dual pumps as it was pulling a lot more amps with 2 pumps rather than one and would blow the fuse from time to time, we now have a fuel pump relay that is giving them power directly off the battery, and putting no strain on the wiring.

[135Pats]

Originally Posted by Vargasturbotech

If you have replaced your LPFP and are blowing fuses, check over all your wiring carefully. I also went up 1-2 fuse sizes when running the dual pumps as it was pulling a lot more amps with 2 pumps rather than one and would blow the fuse from time to time, we now have a fuel pump relay that is giving them power directly off the battery, and putting no strain on the wiring.

Very helpful, I had not given that any thought. There’s nothing special about the FFTEC pump, it’s just a 455 with an adapter to run inline. Wiring etc is not exotic at all and was soldered to the bucket wiring, so wouldn’t this be an issue on a lot more people’s cars running secondary pumps?

By chance do you remember the fuses you used? The one that blew on my pump was a tiny little green one, but again I am a total noob with regards to the electrical side of this car.

Would be ridiculously annoying if I just kept blowing fuses every month….

[Tony@vargasturbotech]

Originally Posted by 135Pats

Very helpful, I had not given that any thought. Theres nothing special about the FFTEC pump, its just a 455 with an adapter to run inline. Wiring etc is not exotic at all and was soldered to the bucket wiring, so wouldnt this be an issue on a lot more peoples cars running secondary pumps?

By chance do you remember the fuses you used? The one that blew on my pump was a tiny little green one, but again I am a total noob with regards to the electrical side of this car.

Would be ridiculously annoying if I just kept blowing fuses every month.

If I remember correctly it comes stock with a 20 amp, we went with a 25 or a 30. It took care of the problem. If you keep blowing fuses you have a problem somewhere, something is causing the pumps to draw too much amperage popping the fuse.

[135Pats]

Originally Posted by Vargasturbotech

If I remember correctly it comes stock with a 20 amp, we went with a 25 or a 30. It took care of the problem. If you keep blowing fuses you have a problem somewhere, something is causing the pumps to draw too much amperage popping the fuse.

Gotcha. The plan for now is to just drive the car and see what happens over the next month or two, it’s otherwise running quite well so I’ll play it by ear. If a fuse gets smoked again, will need to upsize the fuses and re-check the wiring. Good news is since the issue appears to be on the low pressure side, takes a fraction of the time to get in there and see what the deal is. So not a huge time commitment on my part if I had to swap out fuse again.

Thanks man.

[Tony@vargasturbotech]

One last thing, we also had a car where the stock LPFP shorted out inside, this caused it to blow fuses over and over, sometimes right away, sometimes after 2-3 minutes. The wires got so hot they melted together, be careful to only go out 5-10 amps on the fuse, as you want it to still be a fail safe if something like that happens.

[135Pats]

Originally Posted by Vargasturbotech

One last thing, we also had a car where the stock LPFP shorted out inside, this caused it to blow fuses over and over, sometimes right away, sometimes after 2-3 minutes. The wires got so hot they melted together, be careful to only go out 5-10 amps on the fuse, as you want it to still be a fail safe if something like that happens.

Good call, if I do go up a level in fuse amp, will be sure to only go up 5 amps. Blowing a fuse I can live with, were it not for me being stranded when it happens. I wouldn’t mind swapping fuses, but I certainly do mind being stuck on the side of a highway. Have little tolerance for that.

I’ll keep driving and report back, I would have thought a voltage/amp problem would be immediately apparent or close to that, but this took a solid month for the fuse to blow, and it happened under a near 0 load situation so nothing was being taxed or under heavy duty cycle. So we’ll see, maybe just crappy luck and it’s a one-time thing.

Wish we had a decent rep system on this forum, thanks for the help dude.

[135Pats]

Hey guys,

Some updates here, would love your input. Still running a 20 amp fuse as there was a kink in a fuel line, which to me would appear to be the culprit. HOWEVER- the car is still demanding the same type of fuel PSI at idle, high 80s which it pegs very consistently. At this point the only thing I can think of is a bad fuel regulator/filter unit, but wouldn't that lead to less pressure, not more? I have no idea what would cause the car to have such poor control over fuel PSI low pressure. Again, nothing exotic about the FFTEC pump. Below is the latest, all taken from last night.


1. Cold start behavior. As you can see, it pegs high 80s instantly and doesn't really budge.
http://www.datazap.me/u/135pats/cold-start

2. Just cruising under light load and throttle. Similar story, PSI pegs around 87-89PSI stays there.
http://www.datazap.me/u/135pats/0-50-cruising

3. 3-4-5 pull with the same results before. Things look OK fueling wise to me WOT, suppose trims could be tighter but the car is still adapting with only 50 miles since the last reset.
http://www.datazap.me/u/135pats/3-4-5


The car threw no codes at all but I did find a p2c7c when I got in the car, so i'll be replacing the post cat o2s soon. Doubt that's at all the issue here though.