Resolved 99 GST Fuel pump not turning on.

[Snailtrail420]

Any help would be very appreciated.. I have a 99 GST and I was just completing it. Has all brand new fuel system with Walbro 255hp. I manually turned the fuel pump on with ECMLink. And I heard a click from the MFI relays but no fuel pump turning on.

I swapped the stock fuel pump back in to isolate the new fuel pump and also doesn't turn on. The car has not been running in a lot of years so I'm unsure what may be. I tested the two wires coming to the fuel pump pickup and both show 11.8v.

Is one of them wires supposed to be a ground and showing very little voltage?
Wondering if i need to rewire the ground wire if so, I was planning to do a fuel pump rewire also at some point.

 

[evil_eagletalon]

The fuel pump grounds to the fuel pump hanger on a 1g i would suspect the same on your car.

 

[Sirius1995]

Sounds like no ground issue to me too

 

[Sirius1995]

Also thats a common issue on evos with walbro pumps that every now and then you have to feed straight 12V to the pump, it's something to do with the relay but this fixes the issue

 

[evil_eagletalon]

Pull the pump hanger back out and check power right at the pump. And look at the ground connection.

 

[luv2rallye]

On the 99 GST the fuel pump has its own large black-white ground wire that connects to a large black wire (in connector E-60) which goes the front floor upper cross member left side (under the driver's seat) - which often makes poor connection with age.

 

[Snailtrail420]

Yeah, I fixed the issue when diagnosing it.

When I spliced a piece of ground wire into the black/white ground on the fuel pump connector wire, and grounded it to the body of the car the fuel pump finally turned on and started priming the fuel system.

Now I wonder, with the key in the on position not cranking I read the fuel pump shouldn't be on?

I got the fuel pump turning on with key in on position and it stays on and humming. I have all brand new AN fuel lines line from tank and all larger filter, and fuel rail and injectors, first time running fuel through it so maybe its also just filling the fuel system and stop running also after?
Or maybe its because DSMLink ECU?

Wonder if that's normal anyways to be fuel pump always on in the ignition position in the ON.

On the 99 GST the fuel pump has its own large black-white ground wire that connects to a large black wire (in connector E-60) which goes the front floor upper cross member left side (under the driver's seat) - which often makes poor connection with age.

It must have been that

 

[luv2rallye]

It's most likely dsmlink keeping the fuel pump on. On the factory 2g turbo, the fuel pump only runs while the engine is turning getting CAS pulses - so when cranking and actually running (most likely a crash safety feature). The 2g NT powers the fuel pump when "ON" (whether engine is turning or not) and "START".

 

[Sirius1995]

Check the wiring diagram and see where the starter gets the power from, fuses, relays, grounds, splices etc

So fuel pump is not meant to "run" ignition on, just prime the system and ready to be cranked, once crankshaft sensor notices rotation to the engine, it gives signal to the fuel pump to feed power to it which turns pump on, so technically you just bypassed that

If the engine won't turn when you turn the key, it's gonna be something between key to the starter or battery to the starter or starter itself

If the engine rotated when you turn the key but no start, then I'd check cam sensors, crank sensor and timing and if possible dtcs stored

 

[evil_eagletalon]

You probably selected keep pump on through ECMLink. Double check that. You say you added a ground so you pretty much eliminated the factory ground wire. If you can find diagrams of the fuel system I would be of better help.

 

[Snailtrail420]

It's most likely dsmlink keeping the fuel pump on. On the factory 2g turbo, the fuel pump only runs while the engine is turning getting CAS pulses - so when cranking and actually running (most likely a crash safety feature). The 2g NT powers the fuel pump when "ON" (whether engine is turning or not) and "START".

Ok yeah the car actually used to also be a non turbo 2.4l spyder. i wonder if that could be it.. thats likely a setting in the 2.4l ecu though i expect eh? Yes ill check all my dsm link settings also. Maybe i have it manually set to always run.

 

[snowborder714]

If you checked the "Activate Fuel Pump" and left it on, that will cause the pump to run all the time while the ECU has power (see box on right side of first screenshot below). Any version after 3.36.73 will prime the fuel pump for about five seconds when the key is turned to on without any additional inputs required.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

 

[99dsmer4g63]

Ok yeah the car actually used to also be a non turbo 2.4l spyder. i wonder if that could be it.. thats likely a setting in the 2.4l ecu though i expect eh? Yes ill check all my dsm link settings also. Maybe i have it manually set to always run

Fill out a vehicle profile. We don’t know what you have in your driveway.

-Daniel

 

[Snailtrail420]

Fill out a vehicle profile. We don’t know what you have in your driveway.

-Daniel

How do you do the vehicle profile? Is it something on the my profile account you can put in car details?

 

[Snailtrail420]

Fill out a vehicle profile. We don’t know what you have in your driveway.

-Daniel

Ok i made one i figured out where to do so.

 

[Snailtrail420]

If you checked the "Activate Fuel Pump" and left it on, that will cause the pump to run all the time while the ECU has power (see box on right side of first screenshot below). Any version after 3.36.73 will prime the fuel pump for about five seconds when the key is turned to on without any additional inputs required.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

Yeah it actually was activated on still through ecmlink once i made sure it was unchecked it stopped running all the time. I got the car running also which is great. I bought it and didnt run since 2016 when it had a 2.4l non turbo engine so alot of progress..

 

[Snailtrail420]

Hey if anyone here would be awesome enough to checkout my new post there and look at my logfile on ecmlink its just 15 seconds or so long on the cars first start.. i got my car running and hooked up to ecmlink. it just briefly started and then died but it is still project status of getting it going.

Im just wondering about what to do to get it to idle well next, im going to aim to get it running proper afr next once i get a better running time log to work with. And i was reading i think with the fiav block off plate on the 1g throttle body im using.. with it deleting a lot of the idle components, i must hold it manually the throttle open a couple minutes at 1500rpm to warm it up im thinking.. and i see the tps is at 3% when im not on the pedal so i must need to adjust that. it has the 2g tps i put on and thought it was pretty near accurately mounted..

https://www.dsmtuners.com/threads/4g63-project-car-on-speed-density-first-start-wont-idle-logfile-attached.545575/