Fuel Pump Runs Continuously - how to prevent....?

[LS3_Z4]

Hi,
I am swapping a 2010 Camaro LS3/TR6060 drivetrain into a 2004 BMW Z4. (first that I know of)
It will be California CARB/smog legal......

I have it mechanically in, and reflashed enough to get it running.
Driving around the block is AWESOME - think modern Cobra...........

I am used to vehicles that only enable the fuel pump for about 3 seconds if the engine is not running.
Is that how the LS3 should operate?

My swap has the fuel pump running continuously when the ignition is in "run".

I do not have the Chevy "Fuel System Control Module", so am running the output from the Chevy ECM connector X1-50 (through a signal inversion transistor) to the BMW Fuel Pump Relay control. (BMW needs "low" to enable the relay coil)

I have tried the "F0585" (FSCM Fitted) parameter both left at default "yes", and have reflashed to "no".

any suggestions?

Thanks

[LastCall]

Sounds like a cool project! I'm from CA too.

The GM ECMs should only run the fuel pump for a few seconds on key on. I don't think the FPCM parameters in the tune do anything if its not fitted with one. It may be easiest to run a new relay off the ECM and tap into the fuel pump supply wire. That how most of the conversion harnesses do it.

Are you running the factory BMW fuel pump and regulator?

[joecar]

The GM ECM runs the fuel pump while it sees CKP pulses... when there are no CKP pulses, the ECM times out after 2 seconds (i.e. and then stops running the fuel pump).

You possibly have a short or a bad ECM.

[LS3_Z4]

thanks guys.

I am using the factory BMW fuel pump, but have deleted the in-tank filter and regulator.
I have gone to an external Corvette style filter/regulator/return to make it easier/cheaper to change, and get the higher fuel pressure required.
I have yet to determine if the BMW fuel pump will be able to sustain enough volume/flow at the higher pressure under load at max rpm.
if not I will change the fuel pump as well.

My "polarity inversion circuit" works as expected, and controls the BMW relay fine. just the input to it (see below description) is always active as long as the ignition key is set to "run".
(so if I were to run an external relay instead it would do the same thing)



there appears to be a typo in my Factory Service Manual (2010 Camaro). page 9-328 schematic shows ECM K20 conn X2 pin 10 being signal 465 "Fuel Pump Relay Control". However the connector pinouts show this to be true for the LLT engine. (no differentiation for LS3)
so what I have used it ECM X1-50. this matches the connector pinout drawings, the color coding, and goes properly to the Forward Lamp Harness conn X102 pin 10.

but perhaps I am using the wrong control signal?

the engine seems to run just fine, so I have to assume I am getting the proper CKP pulse to the ECM (when running),
and it would seem impossible to get a CKP pulse when I just turn the key to on and have not started it (yet the fuel pump runs continuously).

other than buying and swapping ECMs, what else can I test?

I am merely having the BMW key ignition "run" & "crank" going to the KR74 relay coil.
any other "stuff" that should be checked?

thanks

[LastCall]

Can you trigger the fuel pump circuit in the DVT controls in the scanner to see if you are tapped into the proper signal pin from ECM?

Sent from my SAMSUNG-SM-G900A using Tapatalk

[LS3_Z4]

that sounds like a great idea....

but I am confused.

when you say 'scanner", I assume that means the EFILive V2 ?

what is "DVT controls" ?

thanks,
obviously a neophyte...

[LastCall]

Access The EFILive V7 scan tool through the PC. The DVT is the last tab within the scan tool. Select file drop down and then connect (should be e38 controller) and then you should have output control in the engine tab.

[LS3_Z4]

thanks -

I had been using only the scanner.

I'll connect with laptop tonight......

[LS3_Z4]

got the scanner hooked up with the PC.
I had not done that - impressive abilities!

However.......
I do not see a FUEL PUMP control - there is no relay in the fusebox - I assume that would be in the (missing for my conversion) Fuel Pump Control Module

I do have Fan Speed Relays, and AC RELAY and Powertrain Relay.
All of those can be controlled and I hear them click.

I do have 4 "Active Fuel Mode Solenoid" control boxes controls..... ?

I do have Secondary Fuel Pump control - but when I try to activate it, EFILive says I do not have that fitted in my car (very likely true!)

so what am I supposed to be trying to enable to see if the ECM module output toggles?


Maybe I need the Control Module?
does the ECM talk to the Control Module directly over one of the busses? (and the signal I thought was a relay control is not ?)
(it also would then modify the duty cycle PWM under light load (?) )


I have attached the screen capture of what I see....as well as the schematic page from the FSM

20504 20506

[Tre-Cool]

It's the tickbox where it has Fuel Pump Duty Cycle.

ticking & unticking that will turn it on/off.

[LS3_Z4]

tried that enabling the Duty Cycle box, and changed duty cycle from 0 to 100, and still no change on ECM output X1 pin 50 (always stays +12 following ign

should I be using a different pin? / signal ?

is the Fuel Pump Control Module really not needed for 2010? could the commands be sent over the bus instead of this single pin?

[joecar]

...
... there is no relay in the fusebox - I assume that would be in the (missing for my conversion) Fuel Pump Control Module
You will have to install a relay to 12V.



I do have 4 "Active Fuel Mode Solenoid" control boxes controls..... ?
No, these are for the DoD (Displacement on Demand) solenoids; DoD is aka AFM (Active Fuel Management).



I do have Secondary Fuel Pump control - but when I try to activate it, EFILive says I do not have that fitted in my car (very likely true!)

so what am I supposed to be trying to enable to see if the ECM module output toggles?

Maybe I need the Control Module?
does the ECM talk to the Control Module directly over one of the busses? (and the signal I thought was a relay control is not ?)
(it also would then modify the duty cycle PWM under light load (?) )

You will need a relay... you will have to set the Pump min and max PWM to 100% in the tune file (so you don't beat the relay to death)... I haven't done a conversion like this, but that's what I would try.

[LS3_Z4]

I have plenty of relays I can use.
but what will control it?
what signal (name, circuit #, ECM connector, etc).

I cannot get any output to toggle that would control a new relay...........


see post #11 above :
I tried using the EFI Engine COntrol S/W to manually set the Pump PWM to 99.6 (the max it would go), and I still got no change in (what I thought) the control signal....

what output from the ECM should I be looking at if it is just a single signal that should control a relay?

[joecar]

In the schematic, what is the nature of the signal from the ECM to the FSM...?

edit: I meant FPCM.

[LS3_Z4]

I included the schematic page in post #9.
it is the signal in the upper right.
the Service Manual lists circuit 465 as "Fuel Pump Relay Control".

so I was expecting a DC +12 when engine running (crankshaft sense pulse signal present) or gnd if not running.
but it is always +12v with ign on (even if I have never cranked the starter, so definitely no crankshaft sense pulse)

[LastCall]

X1, pin 50 should be the correct signal. And you are getting a constant 12 out of that with key on? Maybe try disconnecting that from your BMW wiring to isolate it?

[LS3_Z4]

when running these tests and measuring voltage, I have disconnected the ECU output - it is not driving the relay. I am just measuring voltage.
Next step is to put a light pull down resistor (say 5k) to ensure that the signal is not just floating to +12, but is actively being driven.

I will also recheck my wiring to ensure that I am on the right pin from the ECU.

[LS3_Z4]

well......

good news.

I spent today ripping out a lot of the BMW wiring, and simplifying.
then I put a new relay in.

and now it works!!!!

so obviously something I had done was not quite correct.

thanks for the help, I am back in business again!

[LastCall]

Good deal! Glad you got it figured out.

[joecar]

Good job :cheers: