GT350 Fuel pump issues

[JAJ]

I thought both pumps were on the same basket on the drivers side, and used the venture system to draw fuel from the passenger tank? If that’s the case then everything makes sense.

I've never had mine apart so I don't know for sure. That's why I said "might cause" in my post. The electrical drawing suggests one assembly with two pumps, so you're probably right on that point. The bigger question is whether they are plumbed in parallel so they both draw from both sides or if they operate separately with one handling each side of the tank. If you're swapping out for a different pump, then it doesn't matter in any case.

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[oneill_nolan]

No it wasn’t. It was fairly simple and I was very analytical about it I even modified my basket (see green highlighted area) to clear my ear clamp pliers which are used to clamp the lines onto the fittings.

In the first pic you can see where I cut the pump holder and rounded the corners. I did some other trimming as well using a Dremel. Not hard at all. Once you start, you’ll see exactly where you need to take away material to make the pump fit properly. All of the rounding of corners and basket modification probably were t necessary, but my OCD made me do it that way, lol.

Looks easy enough thanks.

 

[oneill_nolan]

Update to this turns out one of my fuel pumps was indeed dead. But I had more than one issue going on. After replacing the pump fuel pressure was good and the car was happy but still jerking bad. Really bad! Also weirdly my cruise control didn’t work. After doing some research into this I discovered a TSB about the output flange nut loosening slightly allowing the output shaft tone ring to move in relation to the output shaft causing an erroneous signal without triggering any DTCs. The fix for this is to replace the output shaft flange nut along with the driveshaft bolts.



It was fairly simple I didn’t have to remove the exhaust and the driveshaft only has to be removed on the transmission side. It helps to loosen up the center support on the driveshaft to allow more movement so you can push it up and out of the way. I chose to reuse the nut and bolts instead of replacing and just used red loctite during reassembly. It worked! Runs like a clock and no more jerking.



Torque specs: flange nut 105 ft/lb 32mm socket

Drive shaft flange bolts: (12mm 12 point socket)

I tightened in two increments 45 ft/lb then 75 ft/lb in an X pattern.
hopefully this helps someone.

 

[BrakeFade]

I've killed several fuel pumps in my time on higher mileage cars due to running them on E or close to E for too long. They get old, they get hot, they will die.

 

[WItoTX]

These tanks have about 2 gallons left in them even at 0 range. Only reason I know is one day at the track I took mine down to 3 miles left, and when I filled up, could only get about 14 gallons in. A shade more.

I'm betting the pump just failed. It doesn't hurt to never run them dry, but I don't think that was the cause of the failure IMO.

OP, glad you chased down the driveshaft issue too. Lots of folks run into that, and I'm lucky I've not had to deal with it.

 

[oneill_nolan]

These tanks have about 2 gallons left in them even at 0 range. Only reason I know is one day at the track I took mine down to 3 miles left, and when I filled up, could only get about 14 gallons in. A shade more.

I'm betting the pump just failed. It doesn't hurt to never run them dry, but I don't think that was the cause of the failure IMO.

OP, glad you chased down the driveshaft issue too. Lots of folks run into that, and I'm lucky I've not had to deal with it.

That’s good to know. Yeah I’m sure it was a fluke thing with the pump. Living out in the country sometimes gas stations are far and few between but I always try to avoid getting below a quarter tank. It really wasn’t that difficult to do I guess it’s a common thing on these cars. Fingers crossed

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