Do you have the fuel pressure spec for psi coming out of the intank pump and what it should be after the in line pump? I want to go rent a pressure tester tonight and see what i can come up with.

 

the in-tank pump isn't about pressure, its about flow. its function is to prime the main pump, which creates the fuel pressure. These engines will run with a full tank of gas without any in-tank pump (although the main pump will be straining a bit and sound noiser than it should), but when the gas gets down around 1/2 or 1/3rd tank, then the main pump has trouble getting enough gas and your engine starves causing the sort of symptoms you described (stumble, run, stumble, run).

other things that can go wrong with the tank pump assembly... the fuel pickup sock can get knocked off when reassembling.... the short hose that connects the pump to the cover plate can crack or fail... the aftermarket in-tank pumps can be wired backwards...

I believe I'd try disconnecting the fuel line at the tank, connect a spare piece of fuel line, then jumper the pump per the instructions on 'cleanflametrap.com' (I think I linked earlier?)... when the tank pump fuse is removed, you can jumper JUST the tank pump. and see if you get a steady stream of fuel.

 

Can i just pull the relay out and jumper it with the toggle switch from the harness plug for the relay? That way it only kicks on the rear pump also. If this is because my in tank pump was weak then why would it have died the first time when i filled the tank up? Could the in-line pump be weak as well? THe pick up sock had some small tears in it also when i put the pump back in. The rubber hose that went from the pump to the sender i had to reuse because the one that came with the pump was way to small to even go on the pump so i might try and pull the pump back out this weekend and just go get a 2" piece of fuel line for the piece between the sender and pump also

 

the socks function is to keep debris out of the pump. with the sock torn, filling the gas tank stirs up 30 years of accumulated flug in the bottom of your tank, and it could have gotten sucked into the tank pump, causing it to malfunction (this is purely a conjecture).

 

Funny thing was the tank looked super clean when i pulled the pump out. Like real clean. Ill try to get one of them today also when i got get the chunk of fuel line. So should it work the same to jump the fuel pump at the harness plug as the fuse box

 

re: jumpering, sure, dunno why not. if you get a solid steady stream of gas out, then your in-tank pump is probably OK. ideally test it when you're down under 1/4 tank, that will confirm the pickup and hose is OK. I regularly have run our Volvos deep into reserve without any fuel delivery issues.

 

Make sure you replace the little rubber hose (looks like a bellows) that attaches the in tank pump to the fue line. These a famous for splitting when you change the pump and a replacement should include a piece of fuel hose to replace it with.

 

Ill do that once i run the gas out

Thanks ill look at that too. That might be what the piece of ruber hose was for that was to small to go between the pump and sender

 

Surprisingly, I have never seen any "flug" in the bottom of a fuel tank. Say what you will about oil companies, they sell some clean ****! Still, I always put the sock back on--just it in case...

 

I put the sock on. It did have a couple rips but not to bad. And yeah the tank looked real clean. Maybe its a wives tale or just because fuel now a days is way different then the fuel in the 60's

 

Well i pulled my fuel pump from the ank and sure enough the little hose failed and the pump slipped out of it. Got a new hose and reinstalled it. Now it wont go over 45 on the freeway and it sounds and feels like it has a miss. Im hoping that the plugs just fouled out when the fuel pump was messed up. This weekend im going to try and redo the exhaust manifold gaskets and warranty out my plug wires because one broke and i have an old one on there now. Also going to get a new cap and rotor to see if that helps.

 

When you replaced the small hose connecting the in-tank pump to the sending unit, I hope you used 30R10 rated submersible hose. If not, most likely the job will need to be done again in a year.

Take a look at this link here:

In the Tank - 240 Volvo Tank Pump and Sender

It is the most comprehensive writeup out there regarding the in-tank pump.

Not being able to go over 45mph sounds like you still might have a fuel delivery issue

 

It's the hose that came with the pump so i would hope it's up to spec lol. Thanks ill check out that link