Fuel pump wont prime with PowerFC, primes with stock ECU

[WA_Sileighty]

Recently pulled my emanage ultimate in favor of a Power FC. All features seem to be working on the unit but the fuel pump will not prime. I can jump the relay post to get the pump on and the car starts.
If i plug in the stock ECU, the car starts
I replaced the fuel pump relay, though i dont think its the case since it primes with the factory ecu connected.
mods on the car:
2871
740cc injectors
z32 mafs
etc...

the owner of the powerfc before me had the same maf and injector setup, but a different turbo. my current issue however is just getting it started.

any help would be faaaantastic

travis

[jspaeth]

Recently pulled my emanage ultimate in favor of a Power FC. All features seem to be working on the unit but the fuel pump will not prime. I can jump the relay post to get the pump on and the car starts.
If i plug in the stock ECU, the car starts
I replaced the fuel pump relay, though i dont think its the case since it primes with the factory ecu connected.
mods on the car:
2871
740cc injectors
z32 mafs
etc...

the owner of the powerfc before me had the same maf and injector setup, but a different turbo. my current issue however is just getting it started.

any help would be faaaantastic

travis

how does the car start with 740ccs and stock ecu? does it actually hold idle? i feel like it would just be way rich and die...

[xpertsnowcarver]

If its grounding with your stock ecu and not with your PFC, then my first guess would be that the PFC isn't grounding you Fuel Pump circuit. Usually pins 104 and 106 switch.

[jspaeth]

If its grounding with your stock ecu and not with your PFC, then my first guess would be that the PFC isn't grounding you Fuel Pump circuit. Usually pins 104 and 106 switch.


i was gonna mention something similar...i'm assuming this is an SR....which model is your stock ECU....E5,E6,J4,61,62,63,WC?

SR20DET ECU (http://www.240sxmotoring.com/sr20detecu.html)

From there,you should be able to easily get a pinout, and check what was said above....

[WA_Sileighty]

I didnt start it with the stock ECU, just turned the car to ON to hear the pump prime.

stock ECU is #62

do i need to ground it as it goes into the powerFC, or just tap the wire with a ground if it doesnt test as to having one? I am getting power at the relay plug, but i may not be getting a proper ground

[xpertsnowcarver]

No. The ecu has a pin dedicated for the fuel pump so it can complete the circuit automatically. If you want, you can avoid the PFC by simply grounding the wire and hooking up a switch in between so you can manually run you pump. But, that's no fun. Do it right.

To determine if the pins are switched, simply look at your PFC pinout vs your stock ECU pinout.

[WA_Sileighty]

ok, excuse my ignorance. wiring is not an issue at all for me btw, just want to make sure its done right. From what I understand on my harness pin 104 is the fuel pump relay output. What wire then am I looking for that should have a ground to complete the circuit? Would simply grounding this wire not be the way to do it?

[xpertsnowcarver]

Again, No, or else you realize your fuel pump is running all the time, even with the key out.

Compare the diagrams first to determine if the pins are switched. Assuming they are, you should be able to figure out what to do from there.

[WA_Sileighty]

well i just tested pin 104 on the harness (fuel pump relay output)
with the stock ecu the output jumps to 12v when the key is turned on, then after the 5sec timer is up, it goes back to 12v.

with the powerfc connected, it jumps to 12v when the key is turned on, and stays, since the relay never clicked and started the 5 second countdown (engine not started)

so obviously it is whatever is supposed to ground my fuel pump relay. I am having a hard time to know what to look for. the pinout of the powerFC and the stock ecu should be the same since its for a redtop. can you tell me what wire i need to look for that should be retaining the ground? only wire on the diagrams is the one fuel pump relay wire

[xpertsnowcarver]

so obviously it is whatever is supposed to ground my fuel pump relay

Correct.

Are you sure you have the 414AN014 or 414AN020?

[WA_Sileighty]

now i am not so sure, this is getting annoying. is the model number inside the case? i am having a hell of a time figuring that part out.
on the outside of the ecu it reads
PowerFC serial number
PFC SR2014 020-498

[xpertsnowcarver]

Ok. So SR2014 (414AN014) is the right PFC.
My last guess would be the settings in your PFC. For example, with an AEM EMS, one can set a fuel pump not to prime at all. The duration of the prime can also be adjusted. So check your settings. If that's not the problem, then call A'pexi for tech support.

[WA_Sileighty]

well I really appreciate you tryin to help so much. If you come up with anything else that would be awesome. Puts my mind at ease a bit knowing its the right model, didnt want to be wrong on that one. I will try apexi, wanna get my car back on the road.
Thanks to you though we have narrowed it down to the fuel pump relay not having a ground to allow the 12v output of the powerFC to switch it on. Normally i would think just grounding the other side would work fine (the pump wouldnt stay on because the 12v fuel pump output isn't there when the car is off). But I am wondering if anything else is not working right.

[WA_Sileighty]

now it apears to click the fuel pump relay, but still no power to the pump with the PFC.

do i need to look at CAS at this point???

[xpertsnowcarver]

No. The CAS has nothing to do with the fuel pump priming.

How is it that your fuel pump relay clicks on, but the fuel pump is not on? What did you do to get it to click?

Fuel Pump Circuit
Battery(+)___[10A Fuse]______|Relay Power|____Fuel Pump________Ground
.....................................\___|Relay Signal|_________ECCS (pin 104)

[jspaeth]

No. The CAS has nothing to do with the fuel pump priming.

How is it that your fuel pump relay clicks on, but the fuel pump is not on? What did you do to get it to click?

Fuel Pump Circuit
Battery(+)___[10A Fuse]______|Relay Power|____Fuel Pump________Ground
.....................................\___|Relay Signal|_________ECCS (pin 104)


Haha that is a sweet wiring diagram....

I have a PFC for an SR20, and I am pretty certain there are no settings (at least that you can access through the Commander) that have anything to do with fuel pump turning on/off....

This is really strange.......


EDIT: Simple, but check to make sure the pin isn't bent or anything like that and that you have good connections there.

[WA_Sileighty]

I may ignor the relay click, not a reliable test when I am by myself on the car. Gonna reset the PFC to the basemap. Maybe they did sonethin wierd with the tune that's on it. If that doesn't work then wire it up on my own to turn on the pump (lots of relay exp). Then set the idle and see how it runs I guess.
Have done so much with my boost leaks and vacuum lines since my ol tune on emanage, really want to get real boost out of my turbo

[steve shadows]

Make sure your ECCS Relay wire is continuous on your car in the battery area wiring.

It's a thin red wire with black stripe and it needs to go across (where your swap chassis harness is)

[WA_Sileighty]

your talking about the plugs in the battery area that you swap pins around while swapping the sr harness into the car?
I will double check that, but is there a way it should be wired differently to accommodate the powerFC, since it is allowing the stock ecu to power the pump?

[WA_Sileighty]

so seperated the signal wire from the ecu to the pump relay. grounded it at the relay, car fired right up. doing the idle learn as we speak
set it to 50% injector and .12ms for my tomei 740s
vg30 mafs
we will see how it goes, also, should the 02 reading be turned off on the pfc, heard it can be kind of a hindrance, boost controll is turned off

[WA_Sileighty]

Ok, car is running on the basemap. After initializing it, setting my injectors and maf. I let it idle for 10 minutes with nothing on, after 10 minutes i turned on my blower to max, after another 10 i turned on my defroster and headlights.
By the end of this process the car wasn't missing at all, timing was sitting at 15 degrees and idling beautiftly.
I let the car sit for a few minutes, then started it back up. Car was still warm, but timing was back up near 30 deg according to the commander. Drove it around near my house, felt great, great response (didnt boost). Whenever i would come to a stop and check the commander i would still have high numbers in timing, it never went back to 15 degrees.
Is this something I should be worried about prior to my tune? Should I run through the idle learn again, and if so can someone post a detailed synopsis of it, what i need to do to put it into learn mode.
AFRs were fine during driving, end up resting around 15 at idle, richen up during accel.

should I just make a new thread on this? since its a different issue?