Fuel accumulator removal / bypass

[FABombjoy]

I just finished bypassing the accumulator and wanted to share my thoughts.

First, totally worth removing. I now have a rubber-free fuel system. I replaced the accumulator in 99 or 2000 and it was leaking into return port. It serves no meaningful purpose with EFI. It just sits there threatening to leak-through and bypass fuel back in to the tank, taking rubber shrapnel with it. It makes strange noises when you turn the car off.

If I did it again I would not spend the time & money on parts to adapt the stock fuel feed line, especially having to work through the accumulator port. The lack of space and strategic use of impact tools, pry bars, and short-length wrenches to keep the stock lines from kinking make it challenging. Two lengths of nylon fuel tubing ran in tandem with the heater core lines would be far easier.

After removing the accumulator & fittings, I used Eaton p/n 15.163-6-6 to adapt the feed elbow to -6AN


Before:


After:


A new braided hose routed where the stock hard line was. I'm sure if I spent more time I could have found fittings that would mate to the "bulk ring" 24 degree flare, but the 2 or 3 that I purchased would not fit correctly. Initially I'd hoped to run new aluminum hard line but the routing of it wasn't going to work without drilling a hole through the frame or removing the body. So a new braided line was the quickest way to finish the job.


New fuel filter, bottom fitting converted from elbow to banjo. Allows any style of K-jet filter to be used.
If I'd converted to nylon lines, a quick disconnect EFI filter could be used.


To plug the return line, a chunk of original hard line (I think from the old fuel return pipe) w/ the bulk ring/olive/ferrule & nut was used. I just soldered in a random bolt and screwed it back in to the return T. Low fi but free. You can see it dangling there in one of the above photos too. Really a piece of rubber line could have been attached and plugged but I didn't want some vestigial rubber appendix threatening to leak.


Peace of mind, and the only cost is that I will reek of gasoline for the next few days.

[powerline84]

Looks nice man. To piggy back on Luke I ended up doing a similar bypass and accumulator removal when I first went to the efi conversion on the prv. The reason was we figured out on the Dyno that the accumulator had failed in a way that it was bypassing so much fuel back to the tank it couldn't maintain a consistent fuel pressure and was causing starvation issues on high demand runs inconsistently.

So...I would say if you do an efi swap you absolutely should just ditch the accumulator and avoid the Hassles...it may prematurely solve a problem you have not yet discovered lol.


I also switched to the Delphi pump and ditched the Houston huko.

[Tom_hd02]

Luke,
Excellent write up. I just removed the fuel accumulator a few days ago in preparation for EFI, but I couldn't find the appropriate fittings to connect the fuel lines. I ended up cutting the male fittings off the fuel accumulator and welding them together , creating a male-male fitting, but I'd like to eliminate that short rubber/nylon hose from the feed line. Where did get the an-6 fitting?

[Bitsyncmaster]

Do any modern cars use an accumulator? One function of the accumulator is to smooth out the pressure pulses of the fuel pump.

[powerline84]

Do any modern cars use an accumulator? One function of the accumulator is to smooth out the pressure pulses of the fuel pump.

A few modern ls Cars use a regulator/filter combo . Most people who want a simple fuel system for an ls swap or many other swaps use a 2003 Corvette ls wix or ac Delco filter regulator....puts out 58psi constant and also filters the fuel.

[FABombjoy]

One function of the accumulator is to smooth out the pressure pulses of the fuel pump.

I suspect this is DeLorean folklore. I guess I've never seen anyone pressure log just the fuel pump & no injection but I'd suspect it's fairly smooth.

CIS being continuous would be less susceptible to pressure spikes at the engine compared to solenoid injectors. For EFI that seems to typically be handled by fuel pressure dampers rather than something as large as the accumulator.

[AugustneverEnds]

Question: Where did you get your braided line from? I believe my rear feed hard line is leaking (#30 https://store.delorean.com/parts/fue...lator-etc.html) and it seems like there is no way to remove it without lifting the body from the frame. My plan was to have a custom line made. I'm researching where to buy from and what fitting I need on each end.

[FABombjoy]

Its Eaton/Aeroquip FCC0606-06 with matching Aeroquip steel AN fittings.

You can remove 106989 without separating the body but putting a new hard line in its place will be challenging. Not sure what (if any) fitting would be available for the accumulator connection. You can easily use AN for the fuel filter along with a corresponding banjo fitting on the bottom in place of the stock elbow. This also will allow for the use of all fuel filters, including the ones with a captive nut on the bottom rather than just the DMC compatible filters.

As an addendum, I did end up installing a different fuel filter and all straight-through connections. I have an "August" EFI problem with heat and efficient, long highway drives that causes fuel pump cavitation once the cooling pipes have heated the gasoline. Removing the 90 degree fittings and installing insulation on the cooling pipes helped, but will soon implement PWM control to slow the pump down and limit cavitation.