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Discussion Starter · #1 · (Edited)
I have a Brunton Stalker with the L67 Series II SC motor in it. It is stock with the stock ECM,I took the car out for a ride and hit the brakes hard (new pads-bedding them in) and it just died. It just cranks,no start. The fuel pump was not running (aftermarket Walbro) so I put power to it after checking all fuses,no start. I checked the line for blockage and fuel flows freely,I then sprayed starting fluid in intake and it starts up-so it does have spark..Looks like the injectors aren't spraying AND the fuel pump is shut down,does this tell you guys my ECM fried or am I looking in the wrong place?? Thanks for the help Rich
 

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VSS = Vehicle Speed Sensor... typically connected at the output of the transmission for tell ing the computer how fast you're going (auto's use it for shift points, but it's also there for some general tuning parameters)

It sounds like wiring came loose somewhere under hard braking, probably something providing signal to the fuel pump.
 

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Discussion Starter · #5 ·
Ok guys,I checked the injectors and they are getting 12v. The fuel pump is still not coming on and I believe the ecm is not grounding the injectors to spray as it will run on starting fluid but still not with the fuel pump externally powered. Any ideas?
 

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There's no random security/anti-theft settings leftover in the tune, or something along those lines, right? I know some years/models had finicky pass-key or VTC items that would inhibit fuel pump activation. There's also the old fuel pump speed control circuit, but that's fairly simple to eliminate for high-speed always on like non-s/c 3800 cars.
 

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Discussion Starter · #7 ·
This powertrain is in a Stalker kit car. It doesn't have a key,isn't the security for use with the key? It has a Walbro aftermarket fuel pump. Whatever it is,it has me stumped..
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Ya, saw that. The computer is going to always think it's basically in the original vehicle, and you typically have things faked, turned off or ignored to operate in a swap properly.

The pump isn't the concern if it works fine when tested itself. It could be a stocker or aftermarket, and it's the signal getting sent from the PCM/relays/fuses that determines its operation. If there's a reason that signal isn't getting sent, it may be an issue along the wiring path/fuse/relay/connections or something in the PCM not turning on due to a fault/security trigger/etc.

The benefit of swapped vehicles is that you can simplify the wiring to make troubleshooting much more straight forward to hunt things like this down. I'd chase the power signal around with a multimeter, and see if the 2-sec key-on (or power-on, if there's an equivalent switch set-up) prime is sending power, and at least if there's anything sent from the PCM to the pump wire when cranking or running (for a couple seconds on spray). Knowing what is/isn't happening will point you in the right direction. Having a basic wiring diagram for the car/pin-out if the connections helps here.
 

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Right, so that shows the Grey wire from computer to trigger a relay for the fuel pump, which the has a Purple wire that should be a bit thicker to supply positive power to the pump. It looks like they just consider the power-on to run the fuel pump at all times, based on what they offer in this "simplified" diagram.

I'd check for power on those first, when you flip the switch on, and when trying to start it. I'm not 100% on their setup without seeing it 1st hand, but most any swaps deal with the same-ish wiring for 3800's (Fiero's & so on).
 

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Discussion Starter · #12 ·
I will check power there,at least it's a place to start. The weird thing is if I put power to the pump the car still doesn't start. I do have 12v to the injector,but the ground that is going to the ecm is not being activated to spray fuel slong with the pump with no power. The car will start with starting fluid,so I have spark.
 
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