Rebuilding the Fuel System

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
If there is a leak, how did it get it 2/3 of the way there, and fill the sedimenter? I'll crawl around with a flash light and look and listen again.

What makes one die? Is there a fix, or...? Is this a 10k item?
 

javelinadave

Administrator
Staff member
The mechanical lift pumps are crap. I carry a spare in my center console along with the olives and nuts to reattach the fuel lines.
 
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Red90

Well-known member
If you have been running without a sedimenter the check valves get jambed open. If it was not an OEM pump they does quickly. The OE ones last forever as long as there is a sedimenter to catch the rocks.
 

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
Well... based on the pics above, there might have been rocks.


One way or another, I'll pick up a new pump. And I should be able to put an electric pump in real easy now.


I got it primed and started after letting it rest, pumping, then rest, etc... took a while, but it is working now. I have a lot of other things to do that I had hoped to get to this week. I'll see how my motivation is tomorrow!
 

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
One last thing. Since I just slapped the tank on without the skid plate that really looks as it would never be made to fit, I’m wondering about aftermarket skid plates. Any options?

Also, it seems as if a simple bolt to the frame skid plate should be possible. Are there any like that? I’d rather not have to unbolt the tank just to mount a skid plate.
 

Uncle Douglas

Well-known member
Callsign: delete
What makes one die? Is there a fix, or...? Is this a 10k item?

Its a diaphragm pump. Once a pinhole develops it works for crap and aerates/foams the fuel, something you dont want. A good way to determine if pump is not working well is to open the bleeder on the filter head and pump the lever a few times. Fuel should literally spray all over the place and make a mess. If not, pump is done or can't pull fuel due to an air leak or check valve not letting the pump make suction. Cranking your engine to prime the IP is bad for the injection pump. The bosch VE pump is lubricated by the diesel flowing through it. Spinning one with no fluid in it is akin to starting your engine with no oil in the sump.
 

Red90

Well-known member
Normally with the 200TDI and earlier pumps, some dirt gets in the check valve which stops it working. I've never seen a diaphragm failure.

The 300TDI pumps added a screen to prevent this.
 

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
My fuel system was obviously dirty. I'll test it today since I plan on filling up the tank and running a bit, then changing the filter.
 

Napalm00

Technical Excellence Contributor
Terra firma make a cheap bolt on skid that uses the stock fasteners. Just bolting a skid to the bottom of the tank and not using the frame/fasteners is silly...it will crush like a can.

A weak/non working lift pump can definitely cause engine performance issues
 

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
Terra firma make a cheap bolt on skid that uses the stock fasteners. Just bolting a skid to the bottom of the tank and not using the frame/fasteners is silly...it will crush like a can.

A weak/non working lift pump can definitely cause engine performance issues


Right, I hadn't looked into rear skid plates before this, but now that I have not skid plate, and after looking at how it mounts anyway, a proper skid plate is in order.


I will be putting a fuel pump into my order with a new fuel cap.



The truck runs just as it always has, but does seem a bit quieter/smoother. Maybe there was some air getting into the system before. I ran it down to 1/8 of a tank for the first time in two years, and didn't run out of gas! Also, the fuel light just barely starts to blink on the bumps when it gets that low. It looks like there are no leaks, and at 1/8 of a tank, it will take 17.5 gallons to fill, so the sender and gauge are accurate.
 

Toyrover

Well-known member
Tried finding the terrafirma skid plate for 110, but no luck?

QUOTE=Napalm00;23211]Terra firma make a cheap bolt on skid that uses the stock fasteners. Just bolting a skid to the bottom of the tank and not using the frame/fasteners is silly...it will crush like a can.

A weak/non working lift pump can definitely cause engine performance issues[/QUOTE]
 

NPT90

Well-known member
Silly question, any logic to dumping the fuel return into the tank vs back into the filter housing?

I mean is there back pressure to consider?
 

DefendersNW

Well-known member
Silly question, any logic to dumping the fuel return into the tank vs back into the filter housing?

I mean is there back pressure to consider?

Air is the issue - air in the system will purge if the return is to the tank (200tdi and later were setup this way) - any air leak in the system will eventually fill the filter and displace the fuel (19j and prior engines)

We routinely rework the fuel system to the Tdi routing on earlier trucks
 

NPT90

Well-known member
that makes sense, currently it is setup to dump back in the tank from the back of the IP banjo bolt.

Sounds like its in my best interest to keep it there.

Cheers
 

SARTech

Well-known member
Silly question, any logic to dumping the fuel return into the tank vs back into the filter housing?

I mean is there back pressure to consider?

In the right situation fuel returning to the tank can also warn the fuel in the tank. In cold environments the fuel returning to the tank will be warmer than the fuel leaving the tank, on a cold long run that would be beneficial.
 

Red90

Well-known member
In both arrangements the same amount of fuel is always returning to the tank. The problem with the tee into the filter is that it is harder for air to leave the system. It still must leave unless you are continually pumping air in.
 

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
I could be wrong, but I think I'm seeing a bit of results from this work. Obviously, my system was a dirty mess, so that has to count for something.

But over the past two days, the vehicle has gotten quieter. As I've said before, I've suspected that some of the issues I've been having are due to fuel in one way or another. I think air was getting into my system and causing a clatter. I used to notice that it would run 'quiet' like this when I ran B20, I'm now running 100% diesel, and to my ear, it seems quieter than ever.

Over the past 30 miles of driving, I think it is purging that air. I'll be replacing the filter tomorrow (I wanted to let the old filter run to catch any muck left over from the old system before putting a new filter in) and I'll make sure to purge the filter well, then note how it runs for the rest of this tank full.
 

NPT90

Well-known member
Kennedy Diesel 12v centrifuge pump

Found this snooping the interwebs today.

Alloy housing, 2 year warranty, 40K hours life expectancy, 4PSI output. Seems like they are widely considered the best for no performance applications. Also folks find them to be remarkably quiet.
 

rocky

NAS-ROW Addict
RBB, I sure hope you've nailed the cause of the multiple annoying issues you've been having. You truly deserve a serious dose of good luck from the LR diesel gods!
 
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