GT40 electrical/fuel pump issue

Hi guys,
hope you can help me out here! Boat is '97 SS.
Just recently had a fuel pump issue. Turned out to be the relay of the computer. Boat ran perfect, even better then before, which was already good. Happy me!
Only a week or so, and a couple hours of use later: same issue it seemed (no priming of the fuel pump. Engine turns over but doesn't start). Not so happy me.
Figured maybe the relay for the pump went out this time. Changed that out, but no.
A friend told me to bypass the relay and connect fuel pump directly with battery to see if fuel pump worked. Tried that, but killed the whole engine. Somehow, I must have caused a short circuit. (Yes I'm an idiot, and I know it, that's why I usually don't try stuff like this myself). Engine didn't turn over anymore; nada.
I checked the fuse between the battery and the engine, it's fine. Changed relays again; nothing. Really unhappy me.

Had a mechanic look at it today. 3 Fuses (? 60, 15, 12.5) on front of engine were checked and are OK) He found out that the signal from the ignition doesn't reach the pump. He put a wire straight from battery to relay (computer's relay, if I'm correct) to the green/pink wire, so the pump engages as soon as you put ignition on. It now starts giving extra gas, but runs really rough. Doesn't idle.
Mechanic says it's the spark plugs, but since it ran phenomenal only a week ago I don't think so. They might not be perfect (had fuel on them) but that's mainly of the rough running today, I think. Or they must have gone bad overnight.
My guess is that wiring the pump straight to battery 'confuses' the computer, and that that's why it's not running well. Maybe not, or even probably not since I'm an idiot... but either way I don't think the main issue are the plugs.

Any ideas and suggestions?! What might have gone bad when I tried hooking up the pump to the battery? What else to check or try?

Thanks all!

Great, thanks!
Maybe it's obvious when I'm on the boat, but where exactly does it plug into?

Awesome, thanks!

Hmmm, removed jump wire and it started again. But ran same as the time it all went bad: surging at idle. As soon as you put it in gear it stalls. Managed to start a few times like this . Sometimes didn't start, then had to use wires to jump it again, with some extra throttle. Starts and runs super bad/rich, then as soon as I remove wires runs great, then stalls when I put it into gear.
Edit: pump still doesn't prime, but starts anyway, sometimes.

No the reader won't test those. Keep in mind the testing of components will not differ from that of automotive ones. Google how to test them, some Mustang sites are really good.

check this link for more details

STO is Self Test Output...the test connector you can use the jump the pumps to ground..

Just my $.02, but I think the guys here could walk you through some troubleshooting if you provided a little more information and feedback on your tests. It's still not clear whether your fuel pumps are running with turning the key or using the STO and verifying what the fuel pressure is at the rail and whether its holding pressure (to start or running (rough)). I would spend a little more time trouble shooting before I flew someone down and spent that kind of money.

Well I wish had brought in a mechanic from the US 2 weeks ago, would have saved me lots of $$. A wakeboard school without boat...
But I did find some good info that gives me some hope again.
Now to find a good mechanic that understands English so I can show it to them.

And fingers crossed it's not the ecm...

Never been to Costa Rica :)

TRIP wrote: Any $250-tickets from Aus to CR out there?! Heading to boat tomorrow to check things from that screenshot. Well you're involved in fixing it anyway lewy2001!

If there was I would already be there

Lots of good info in that old GT40 Fuel Supply Thread Trip

If you read the whole thread and follow the trouble shooting logic it should pin point your problem. What has me a little worried is that you may have fried your ECM by applying 12volts to the wrong input on the ECM in your initial trouble shooting.

I knew Mark's (Lewy) info would come through for you.

[QUOTE=TRIP] The culprit


The green wire from memory goes back to the dash for the engine alarm cct (SLOW) and the grey is the tach signal to dash. Not sure where that larger 12V red cable is going to though. It may just be the main power wire to dash via dash harness plug.

The v drive wiring configuration in your Super Sport is a bit different to the direct drive.
Being a 97 SS I assume it has the FCC I think I can see it just below LP fuel pump. Can you get a wider shot of that picture to confirm. Another thing to check is for a extra large fuse in the battery box that is actually the power source for the ECM. PCM did a retrofit that eliminates this extra fuse and wiring. They were a known cause of intermittent problems.

Reporting back again...







So as you can see the ground-pin got loose. Everything got corroded. Seems like the boat has been used in salt (was told it wasn't).
Anyway, got the ecm to a guy who's going to try to fix it. If that doesn't work (and if it does, to have a backup for when it goes wrong again), where do I find a replacement? Don't think you can just replace the 60-pin connector, or can you? As for a new ecm, I think they're not available anymore (?), but I saw some threads on PN about replacements or so, or ways to fix them, not sure.... Gonna try to find those threads, but meanwhile any advice is appreciated!
And again thanks for your help y'all! I've been using that other thread linked above as a guide, and mainly this sentence:

Spot on!

Awesome, thanks Gary!
I'll be on the lookout for a C1A1 and will get in touch with t.franscioni for a chip. Hope the guy that has mine now can fix it, even if a temporary fix.