Fuel pump maxed out?

[Heavyfoot07]

Hey guys, I’ve been racking my brain and think it’s finally time to turn to some guys who know a lot more than me about these cars than me.
I’ve got a car here that I haven’t been able to enjoy since I’ve gotten it cause I’m chasing a fuel issue.
Every time I get on it, it falls on its face...I logged it on my x4 and seen that as soon as I get into my upper rpm’s I’m at .49 on the fpdc (which from what I’ve read in here is 98%, might as well be 100%) Also its getting a P0148 code.
It has a 2.76 pulley, Jlt cold air, long tubes, O/R midpipe, catback and a tune from vmp. Not a super modified car..should I be maxing out my pumps at this point?
I have changed the fuel filter and checked the frps and it had no trace of fuel in it....Before I go diving in to replace these fuel pumps, is there anything else that this could be?


Sent from my iPhone using Tapatalk

 

[01yellercobra]

If you have a PPRV delete one of the hoses could be leaking under high pressure. I had an issue with a pair of AEM 320's where they would be fine at part throttle, but under boost the pressure would fall quick. I ended up finding one of the pumps had died.

Something else to consider, how many miles are on the car? These cars are getting up there in age. Parts start to wear out.

I think either way you're going to be dropping the tank.

 

[MG0h3]

A simple test for the fuel pumps is a deadhead test. Get a fuel pressure gauge and with the car idling crimp the fuel line; I think on our cars you’ll have to do it right by the pass firewall. Use wide pliers and a rag so you don’t cut the hose.

The pressure should increase to the max the pumps can deliver. If it dives, your pumps are tits.


Sent from my iPhone using svtperformance.com

 

[Heavyfoot07]

Hey guys, A little update. I ended up going ahead and ordering new pumps just in case I didn’t see any other visible mechanical issues when I got into the tank I could swap them out. I ordered the DEATSCHWERKS 340lph pumps.
I shot my tuner a message to see if I would need a new tune to run these and he said i would. Then come back and said that my stock fpdm would not support them.
So my question is if anyone is running their stock fpdm with these pumps? Is there another set of pumps that would be an easier transition? Should I just go back to a set of stock pumps and add a voltage booster? Any suggestions are greatly appreciated.


Sent from my iPhone using Tapatalk

 

[bigmoose]

Keep the pumps. Get a modified FPDM.

» Modified FPDM Black306.com

 

[Heavyfoot07]

Keep the pumps. Get a modified FPDM.

» Modified FPDM Black306.com

What will I have to do to make this work? My tuner seems to think this may be hard to tune without it being on the rollers.


Sent from my iPhone using Tapatalk

 

[01yellercobra]

What will I have to do to make this work? My tuner seems to think this may be hard to tune without it being on the rollers.


Sent from my iPhone using Tapatalk

Unplug and unbolt the old FPDM. Bolt in and plug in the new FPDM. That's it. Might be worth looking into the wire upgrade since you're there.

I would imagine he only needs to tweak the pump voltage table. It shouldn't need the dyno for that.

 

[Heavyfoot07]

Thanks for the help guys. Would it still be safe to drive the car without the tune for the new pumps
And upgraded fpdm until I receive the new tune?


Sent from my iPhone using Tapatalk

 

[01yellercobra]

Thanks for the help guys. Would it still be safe to drive the car without the tune for the new pumps
And upgraded fpdm until I receive the new tune?


Sent from my iPhone using Tapatalk

I honestly don't see why not. The voltage table is there for when the ECU is reset. Such as after a battery disconnect. The ECU eventually learns the voltages needed to run the pumps. I ran AEM 320's without tweaking the tune and they did fine. Until one died at least.

 

[speedoflife]

My car (stock blower, 2.81” pulley) had a maxed out FPDC (.49) as well. Similar mods. Installed a Boost-a-Pump and now it’s .39 with no problems that I can find. I think one of my pumps is dying (it makes a weird noise at key-on) but everything ran fine until this noise started. These are 17 year old electronics submerged in fuel.....

 

[Heavyfoot07]

My car (stock blower, 2.81” pulley) had a maxed out FPDC (.49) as well. Similar mods. Installed a Boost-a-Pump and now it’s .39 with no problems that I can find. I think one of my pumps is dying (it makes a weird noise at key-on) but everything ran fine until this noise started. These are 17 year old electronics submerged in fuel.....

Yeah I’ve considered that one of my pumps has already failed because I’m seeing nearly 55% fpdc at idle.
Is there anyway to get a hold of the oem pumps or aftermarket pumps...other than eBay? Like, is there a part number? Cause I’ve considered instead of going through all this trouble, just throwing a set of stock pumps (that I know are in good working order) with a. Boast a pump if need be.


Sent from my iPhone using Tapatalk

 

[speedoflife]

Yeah I’ve considered that one of my pumps has already failed because I’m seeing nearly 55% fpdc at idle.
Is there anyway to get a hold of the oem pumps or aftermarket pumps...other than eBay? Like, is there a part number? Cause I’ve considered instead of going through all this trouble, just throwing a set of stock pumps (that I know are in good working order) with a. Boast a pump if need be.


Sent from my iPhone using Tapatalk

I bet that’s what it is. You’re probably on one pump and I’m probably on one pump and have one dying.

I don’t know about finding new pumps - maybe someone will chime in or I’ll find some info researching.

Edit: same as you, my fuel filter is new - mileage is 67k here

 

[01yellercobra]

Yeah I’ve considered that one of my pumps has already failed because I’m seeing nearly 55% fpdc at idle.
Is there anyway to get a hold of the oem pumps or aftermarket pumps...other than eBay? Like, is there a part number? Cause I’ve considered instead of going through all this trouble, just throwing a set of stock pumps (that I know are in good working order) with a. Boast a pump if need be.


Sent from my iPhone using Tapatalk

If you're going to run a BAP just pick up a pair of GT pumps. You shouldn't need a BAP at that point. I'm not a fan of the BAP.

 

[HPLouis]

If you're going to run a BAP just pick up a pair of GT pumps. You shouldn't need a BAP at that point. I'm not a fan of the BAP.

Are the GT pumps 'drop in' or are there any mods, changes, etc.?

 

[01yellercobra]

Are the GT pumps 'drop in' or are there any mods, changes, etc.?

For the most part they're drop in. When I originally did mine I used the flex hose that came with the pumps and attached that to the Y fitting for the PPRV delete. I pulled the electrical plugs apart because the pumps just had spade connectors. But a small pick and about 30 seconds had that taken care of.

 

[Bdubbs]

Maybe I missed it? You checked the frps but didn't change it out because it didn't smell like fuel? They can fail two ways. Mechanically and electrically. When mine failed there was zero smell of fuel in the vacuum line going to the frps.

Sent from my Moto E (4) Plus using the svtperformance.com mobile app

 

[bigmoose]

Maybe I missed it? You checked the frps but didn't change it out because it didn't smell like fuel? They can fail two ways. Mechanically and electrically. When mine failed there was zero smell of fuel in the vacuum line going to the frps.

Sent from my Moto E (4) Plus using the svtperformance.com mobile app

x2

 

[Heavyfoot07]

Maybe I missed it? You checked the frps but didn't change it out because it didn't smell like fuel? They can fail two ways. Mechanically and electrically. When mine failed there was zero smell of fuel in the vacuum line going to the frps.

Sent from my Moto E (4) Plus using the svtperformance.com mobile app

Yes I checked it but didn’t change it....I’ll pick one up and change it out.
I was under the misconception that the one way to tell if they had failed would be visible fuel.

Although that may be one of my issues...I think I definitely have an issue with the pumps with 55-60% fpdc at idle.


Sent from my iPhone using Tapatalk