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'00 Impala LS - 5 Speed and Supercharged

Does anyone have any info on setting up ZZP fuel logs with the Fuelab pressure regulator?

I got rid of the pressure gauge that came with it and installed an aftermarket gauge in the car. I'm seeing about 50psi at idle, but here's the weird thing:

When I get into boost the pressure drops instead of rises. I noticed a couple days ago it was rising in boost, but when I looked again yesterday it was falling. I have a brand new walbro 255 so that wouldn't be it. Brand new fuel filter, and a fp rewire. I'd like to get this dialed in before I start tuning. Any input?
 


outonthetiles said:
Does anyone have any info on setting up ZZP fuel logs with the Fuelab pressure regulator?

I got rid of the pressure gauge that came with it and installed an aftermarket gauge in the car. I'm seeing about 50psi at idle, but here's the weird thing:

When I get into boost the pressure drops instead of rises. I noticed a couple days ago it was rising in boost, but when I looked again yesterday it was falling. I have a brand new walbro 255 so that wouldn't be it. Brand new fuel filter, and a fp rewire. I'd like to get this dialed in before I start tuning. Any input?
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I can't help with the pressure issue, but can you please tell me where you ran the wire through the firewall for the pump? I just started messing with it and can't find any place on passenger side to go through. And I need a straight shot because it looks like the wire zzp gave me has no slack for error. I'm wondering if it will even reach.
Thanks
 
For the fuel pump rewire?

The ZZP kit is junk. Get rid of it and get this one: http://intense-racing.com/Merchant2...&Product_Code=CAS-HWK&Category_Code=3800_Fuel

You'll have plenty of wire to run it however you want. Can't help you with the specifics because my battery is in the trunk and I have mine run straight to that. There's a spot where wires pass through in the passenger footwell under the carpet. I've had good success running wires through there.
 
outonthetiles said:
For the fuel pump rewire?

The ZZP kit is junk. Get rid of it and get this one: http://intense-racing.com/Merchant2...&Product_Code=CAS-HWK&Category_Code=3800_Fuel

You'll have plenty of wire to run it however you want. Can't help you with the specifics because my battery is in the trunk and I have mine run straight to that. There's a spot where wires pass through in the passenger footwell under the carpet. I've had good success running wires through there.
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Thanks. I guess I was hoping that I was just missing an easy access somewhere. I couldn't get it through with that spot you mentioned. Just drilled a hole beside it and ran it in there. Yeah, the zzp kit could use a couple extra feet to allow me to run it along the door sills. Ended up fishing it down the side of console. Have maybe 1/2" to spare.
 


outonthetiles said:
I'm 99.999999% sure fuel pressure should rise under boost and fall under vacuum. Anyone?
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I think on the 97-03 the fuel pressure will rise on the non venturi style pump. With 04+ venturi style the pressure will drop and be steady. Dont really know on the impalas.
 
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you should be rising rate. +1psi per psi of boost with a base fp of 48-52 (KOEO or atmospheric manifold pressure)

pressure regulator could have a bad seat or diaphragm, debris in a hose/line vac or fuel.

inspect for any steel nipple type, plastic fuel line repair splices. they choke the **** out of the fuel flow
 
Ginseng said:
I think on the 97-03 the fuel pressure will rise on the non venturi style pump. With 04+ venturi style the pressure will drop and be steady. Dont really know on the impalas.
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all canisters are rising rate on the 03 and older cars, the NA regulator isn't built for it but it handles positive pressure quite well and does seem to rise at a near 1:1 rate.

04+ guys are ****ed at over 7psi boost, the older cars pressures will rise while the 04+ is stuck at 56-58. on the upside the 04's are quite easy to go to a return type system with just the running of a line from the oem filter location to the engine mounted FPR and delete the OEM FPR in the canister or toss in a 01ish to 03 can.

if your an 04 guy looking to see if your fueling needs help you can temporarily run a line from the manifold to the can. pop up the can, slide the line through the disconnected evap port and hook it to the FPR nipple in the lid of the can. you now have a rising rate deadhead system and if your lean issue disappears its time for fuel system work.
somewhere after 04 though it does seem like they figured out they could leave the nipple off the fpr to save 0.5 cents so this is really only good for the 04 and early 05 guys. any 05+ guys that have found a nipple, please let me know

plain and simple a massive diagnostic value is in knowing boost pressure over your run as well as the fuel pressure. when fuel pressure no longer equals base + boost you've got some upgrading to do with the fuel pump or a line/restriction issue.
 


Turbocharged400sbc said:
all canisters are rising rate on the 03 and older cars, the NA regulator isn't built for it but it handles positive pressure quite well and does seem to rise at a near 1:1 rate.

04+ guys are ****ed at over 7psi boost, the older cars pressures will rise while the 04+ is stuck at 56-58. on the upside the 04's are quite easy to go to a return type system with just the running of a line from the oem filter location to the engine mounted FPR and delete the OEM FPR in the canister or toss in a 01ish to 03 can.

if your an 04 guy looking to see if your fueling needs help you can temporarily run a line from the manifold to the can. pop up the can, slide the line through the disconnected evap port and hook it to the FPR nipple in the lid of the can. you now have a rising rate deadhead system and if your lean issue disappears its time for fuel system work.
somewhere after 04 though it does seem like they figured out they could leave the nipple off the fpr to save 0.5 cents so this is really only good for the 04 and early 05 guys. any 05+ guys that have found a nipple, please let me know

plain and simple a massive diagnostic value is in knowing boost pressure over your run as well as the fuel pressure. when fuel pressure no longer equals base + boost you've got some upgrading to do with the fuel pump or a line/restriction issue.
Click to expand...

Ima take some time and test this on my day off tomarrow and hook up a fp gauge and go for some runs. Pretty sure last time i did i was somewhere around 68 psi and then drop under throttle of about 5 psi and held steady threw boost. I do plan on converting to a older style can/rail (much better filter options aswell) when i upgrade to a walbro.
 
Excellent info, just what I was looking for. Thanks!


My fuel pressure gauge took a **** so I'm waiting on a new one before I can diagnose anything further.


The car starts really hard, seems better with a full tank and if I prime the pump a few times. It also started running like crap. No knock, but down on power and surging. I'm leaning toward a bad fuel pump?

It is however throwing a P1626 code. Could this be caused by something in the canister/pump assembly, or am I looking at another problem with my wiring tuck?

I ordered a factory replacement fuel pump, gonna put that in and see if it helps. Also ordered new nylon fuel hose and a quick connector fitting. There are 2 of those brass barbs in the pressure line, so this will eliminate that restriction.

Really hoping to get all of this worked out before the June meet.
 
yeah get rid of those damned barbs. your pump may be tired and wornout trying to pump all that fuel through 4mm holes....it seems thats one reason why the newer external push-connect line fixes that dorman sells for em....i just dont like em

ive been replacing the kink prone oem lines with rubber or teflon braided hose for years and its just so much more durable and worry free
 


convert the 3/8ths hardline filter end to the quick connect and you can run the easy as hell to replace fuel filter with two quick release barbs and no more rusted up threads! (just make sure the arrow is pointed the right way)

the 255 wouldnt keep up with the fueling (we ran out of ooomph at 5800rpm on our 608whp dyno) so i put an 044 inline with the double quick connect filter. the 044 would really rather have a pressurized surge tank but we needed to get ready for the 1/2 mile so i put it inline

 
Its a brand new walbro 255 in a modified venturi canister. I'm thinking somehow I screwed it up when I modified it to fit the impala. Going back to a OEM canister so I can rule that out. I should learn to do one upgrade at a time so when things stop working properly its easier to find the mistake.
 
**** the venturi cannister. it blows, you still cant supply consistent fueling with a low tank and heavy acceleration...hell your bleeding off valuable godamn volume to power a venturi that can barely keep up with oem WOT fuel demands at 1/4 tank.

the best solution ive found is to hookup a 2nd or third pump to the oem FP relay power and plumb its hose to fill the canister, drop the can down, flip the pump over the rear of the can lip and into the tank (its sock will hang just past the bottom of the can when testing its fit out of the car) that "out of the can" pump can supply the venturi setup at the same time if thats what gets your rocks off....

that pump should last forever at only 0psi of load.

i did ths on the whippledRiv and it kept a weldon 2035 happy drawing from the can. while i hoped the 044 would fix the TR i couldnt get rid of the air bubble issue we've had...so the TR has a nearly new OEM vette pump in a box for its new "venturi" pump

voila, now you have a god damn full fuel canister. now you can race your car with a low ass fuel level and a full can

im sorta goin overboard on alot of stuff but im also trying to go for a staged pressure system on the TR to up base and max fuel pressure and stretch the legs out farther on the 90lb'rs

what im dying to do is ditch the charcoal cannister above the tank and make the surge tank and 1st stage pressure regulator nice and compact next to the can lid and service hole. then the inline 044 can draw straight from a pre filterd surge tank kept at 15psi with a cheap carb regulator and returning to the oem can return.... there's not enough headroom for an air bubble at the top to maintain pressure but with baffles making sure no air gets down to the 044 suction and return at the bottom rear of the new surge tank (easy to get to under the car)

insanity i know
 
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