Rolls-Royce and Bentley Forums banner
1 - 20 of 108 Posts

·
Registered
Joined
·
85 Posts
Discussion Starter · #1 ·
Hello,

I have a 85 Sliver Spirit thats been sitting for a while, I emptied out the old gas and the tank looks ok no rust just a thin layer of gum on the bottom. My question is should I hear the fuel pump when I turn the key to the on position? Because I am not hearing it. I was going to tap on it but I thought I should ask first. I have attach two pics one is the fuel pump and the other looks to be the filter?? Fuel filter looks pretty old. Also if I need to purchase a new fuel pump any suggestions on what one to get?

Thanks in advance!
 

Attachments

·
Registered
Joined
·
1,428 Posts
If you can, put your hands on it while somebody else cranks to see if it runs. Or jump the fuel pump relay
 

·
Registered
Joined
·
3,743 Posts
Do you have carbs or fuel injection? There are different components for each and sometimes if your not familiar with either, a component may be assumed to be something it is not. Example, A carb car will have a check valve and a FI would have a fuel accumulator. They both have very different fuel filters. Chapter K of TSD4400 has the fuel flow diagrams and related info.
 

·
Registered
Joined
·
85 Posts
Discussion Starter · #7 ·
I have fuel injection with the fuel distributor. I just found the online manuals I will check that section out. I think the second picture I posted is the fuel accumulator. Thanks for the info..
 

·
Registered
Joined
·
3,743 Posts
Yes it is. My 1980 SWII has fuel injection. The injection and related components are Bosch. There may be 2 filters in tandem and have Bosch numbers on them use those numbers and source from a Mercedes parts house.
 

·
Registered
Joined
·
85 Posts
Discussion Starter · #9 ·
Oh okay got it will do thanks. BTW I went to chapter K of TSD4400 and it said on the first page at the bottom fuel injection is cover in other sections of the site?? Not sue what sections they are referring to..
 

·
Registered
Joined
·
85 Posts
Discussion Starter · #12 ·
So I ran a wire from the battery to the fuel pump and the pump was working fine or at least it was making noise like it was. I tried to start the car up but nothing. I don’t think fuel is making its way up to the engine. I noticed a humming noise near the fuel distributor with the wire still connected to the fuel pump and the hum went away when I took the wire off. I also heard a gurgling sound from the back of the fuel tank with and without the wire connected. I plan in replacing the fuel filter when it arrives do you have any suggestions for me?

Thanks!
 

·
Registered
Joined
·
1,428 Posts
Your fuel lines are probably gummed up. You'll need to flush out your fuel distributor and possibly rebuild it or you may get lucky and just need to free the piston. The distributor is basically a device that works in two halves where the fuel from the fuel pump goes into the bottom half and the injectors are fed from the top half with the piston acting as a valve that lets in fuel from the bottom to the top. If it's stuck, then you'll either get too much fuel and none at all.

You may also need to flush your injectors. I put together a high level video of how to do so for someone on the Mercedes forum, but it should apply to any CIS injeection system.

 

·
Registered
Joined
·
85 Posts
Discussion Starter · #14 ·
Okay, so just take the fuel distributor off and clean with brake cleaner? Any tricks or issues with removing it?

Also so is my relay bad for the fuel pump? Any idea why the gurgling noise in the fuel tank? fuel accumulator?
 

·
Registered
Joined
·
1,428 Posts
Just use a flare wrench to loosen the lines as the nuts are soft and you may need to clock the 3 screws on top with an impact screw driver if they've been on a while (my experience with Mercedes)

Gurgling at the fuel tank may be the return (my guess)
 

·
Registered
Joined
·
85 Posts
Discussion Starter · #16 ·
Got it thanks. I figured it was the return, the filter is probably clogged. I found this video on youtube he said that the injectors have filters on the inside and will damage them if you try and clean. He recommends replacing them If I understood him correctly.

 

·
Registered
Joined
·
3,743 Posts
The injectors do not have filters. All fuel filtering is done well before it gets to the fuel distributor and injectors. The injectors are merely squirt nozzles with a spring. The possibility that all are clogged to prevent flow is a stretch. Remove the fuel line before the distributor first to see if you have flow by placing a hose over the pipe to direct the fuel into a container or ground.
Why not simply start at the source......the pump..and add 12v to see if it functions. Many fuel issues have an electrical cause.
 

·
Registered
Joined
·
1,428 Posts
Ethanol fuel will turn into syrup after 10 years. It can easily clog injectors and the fuel distributor piston. One thing to check is to press on the air flow metering flap. If you feel a lot of resistance or none at all. Your piston is stuck.
 

·
Registered
Joined
·
85 Posts
Discussion Starter · #20 ·
The injectors do not have filters. All fuel filtering is done well before it gets to the fuel distributor and injectors. The injectors are merely squirt nozzles with a spring. The possibility that all are clogged to prevent flow is a stretch. Remove the fuel line before the distributor first to see if you have flow by placing a hose over the pipe to direct the fuel into a container or ground.
Why not simply start at the source......the pump..and add 12v to see if it functions. Many fuel issues have an electrical cause.
Good point! I tested the fuel pump and it works so I have to follow the line now to the fuel distributor and disconnect and check to see if I have flow. I can't do it unit next week so I will report back.

Thanks!
 
1 - 20 of 108 Posts
Top