Early model in-tank and external fuel pump not running - single pump retrofit?

[5mall5nail5]

Hey all - have an early model (6/87 build) 325(e) that I've swapped a 24v setup into. It ran for years. It did have weird starting issues (when hot) back when on the M20 setup when it was driven regularly and I attributed that to some failing sensor and decided to swap the entire engine after mucking with it for a while.

Haven't driven the car much at all in 5 - 6 years. Finally getting it back on the road. It's always started to move around the driveway so I don't know if it was down on power, etc., but now she won't start.

I have spark - hooked a timing light around one of the M5x coil packs and it flashes while cranking. That means the DME is good, also. I jumped the fuel pump relay (87 to 30) and have 13v (trickle charger plugged in, car off) at the connector on top of the tank under the rear seat. Haven't gone to the external pump yet, but my understanding was that the in-tank lift pump is powered off of a splice/split at the external pump. So, considering that I have power under the rear seat I should have power at the external. So, it's possible my one pump was failed all along and now the other is from sitting - who knows.

I am considering retrofitting a single Walbro or Bosch or AEM or whatever - but, unlike E34s/E36s that I usually muck with, this looks annoying. It seems that since the in-tank is a lift pump that the larger(?) line may not be able to support fuel injection pressures. Looking online, the in-tank is like $500+ (!?) and the external is $120+, not about to spend $600 on fuel pumps but wanted to see if anyone has retrofit single in-tank pumps recently as all the articles I find are pretty ancient and either incomplete or pics dead, etc.

Any thoughts are appreciated!

[reelizmpro]

Search. There are a few very good threads that explain what needs to be done but the jist of it is you get a Walbro/TRE pump, retrofit it into the intank carrier then eliminate the external pump and bypass it with the appropriate fitting. Just note that the intank pump is a low pressure pump and the stock carrier outlet hose isn't designed for high pressure. So you will need to address this to make sure it doesn't split on you. I cut the hose as short as possible and installed the pump higher where the outlet is right at the opening of the tube and installed two hose clamps.