Community Forums

dale1 · 11-03-2021, 04:00 PM

Just received the FASS pump in the mail. gonna start the install in a few minutes.

questions? why not install the pump in the back drivers side bay where the primary filter is located? Just wondering?

thanks, dale

Rob_M · 11-03-2021, 05:32 PM

Quote:

Originally Posted by dale1

Just received the FASS pump in the mail. gonna start the install in a few minutes.

questions? why not install the pump in the back drivers side bay where the primary filter is located? Just wondering?

thanks, dale

I see no reason not to put it there. It can go anywhere between the tank and the engine actually the closer to the tank the better. But that’s not possible on many rigs.

Sspdiesel · 11-03-2021, 06:40 PM

Quote:

Originally Posted by dale1

Thanks Friend. I'm open for all and any advice at this point. Can you please tell me where the engine position sensor is located. Or how to locate a part number. I'll get one on order and change it also.

congratulations on the new coach. i'm new at this also and we are really enjoying it. Even with these problems.

dale

Long day just got in, had to drive to Maryland , to look a boat engine issue ..
I will tomorrow send you a picture of location .. of both
There mpu mag pickup , basically a ac generator
they make a ac pulse . Can check with meter .. while cranking .
it only take a small piece of something on magnet part that goes into blocks
No start ,

This affect timing .. when. To fire injectors , no signal no injection ..

First get your fuel system back to normal prime it the right way
Usually when it injectors some fuel , it smokes during cranking look at exhaust .

jacwjames · 11-03-2021, 07:07 PM

You can install the FASS at the Primary filter location. Once it's primed shouldn't be a problem.

Then the trick will be to route a return line back to tank.

In my case it was easier to mount it up front. I was able to pull an ignition sense from the front fuse panel. Power supply was also easy. I was able to use the original pickup port for the Fass Pump and put a return to tank in the vent opening.

There's more then one way to skin a cat, just depends how much trouble you want to go through.

dale1 · 11-04-2021, 05:15 AM

OK, thanks to all.

I started the install last night.

I don't have much room above the tank and filter access would be difficult in future so decided to mount the Fass Pump in the primary filter location.

I removed the Primary Filter and with slight mods ill be able to use the same bracket for the pump location. will need some 90 degree fittings for hoses.

Wiring should not be too bad:

The kit came with a return hose sleeve the would go in the filler tube, but it is much to small?

We have reservations already for a trip planned Saturday.

Darn fuel pressure sensor is still unavailable.

Jim, what were you talking about previously with a relay?

Thanks again, I cant tell you how much i appreciate the information.

dale

jacwjames · 11-04-2021, 05:50 AM

Not sure the context of which relay

But it is important that you disable the transfer pump but you have to fool the ECM into thinking is there so you have to install a fooler relay, it provides enough resistance to fool the ECM into thinking there is a pump running. Basically unplug the pump wiring harness, take the two wires to a relay.

I pretty much copied my install from Zmotorsports, he is a great resource for modifications and provides videos on much of his work. Here is one on the Fass Install, at 23 minutes in he discusses the Fass Fooler Relay.

https://www.youtube.com/watch?v=GVszhK4JFcg

I did mine similar, ran wires from the lift pump location to my rear passenger side electrical bay, attached to a relay, and mounted in the compartment. I have tried to add labels to everything for future reference.

Here is a post I did when I installed my FASS pump, post 10 shows the pump and return line setup. Post 16 discusses the fooler relay. https://www.irv2.com/forums/f123/mon...ns-535854.html

I've put about 5K on the rig since the install so I guess it worked.

jacwjames · 11-04-2021, 06:02 AM

Also, there is some debate on whether you can just use the existing return line to return excess fuel back to tank through the transfer pump. Some say the ECM doesn't like the excess pressure. That was the advantage of putting the pump near the tank.

Used the original feed line to push fuel to the back and was able to easily tape into the vent line on the tank for the excess fuel line from the FASS. I had to have one ~10' line made up for the FASS to pull fuel from the tank and then just hooked the original line up to the FASS for pushing fuel back to the engine.

I bypassed the original lift pump on the fuel supply line, just put a union to connect the two hoses. The reasoning for this was that there would be no opportunities for leaks from lift pump on the fuel feed line.

I left the original fuel return line from the CAPS pump in place.

dale1 · 11-05-2021, 06:16 AM

man. that is good info. I'm intrigued with using the existing return fuel line back to the fuel tank? since i mounted the fass pump in the rear of the coach, I'm faced with the daunting task of getting fuel line back to the front of the coach. started looking last night and i don't have clear picture on how to attempt that. "metal fish tape"? or plastic conduit?

also. I mounted the new wiring harness in the rear battery compartment. Seem logical? However, i can not find a 12v ignition source that I'm comfortable with in the engine compartment. "crazy" I know the ignition circuit only energizes a relay? But nothing seems obvious.

any ideas? even the slide out relays did not show a ignition source? thanks, dale

jacwjames · 11-05-2021, 06:35 AM

Post a picture of your rear electrical bay, there may be sources there, just have to see what you have. Does your bay look like the parts page I inserted in Post #79.
Some of the wiring diagrams for my 2002 Windsor show it is the same as the Sceptor. The parts page I posted may be close to what you have.

An owner of a Dynasty who I communicate with on a regular basis about some of the mode's I've done had installed a FASS pump system on his coach and he took the time to contact Cummins, they advised him to run a separate line as the additional flow through the return line might cause back pressure to the system. The ECM does monitor for over pressure so it seemed logical to me.

Running the additional return line was what drove me to mount my FASS in the pump near the tank.

I also installed a fuel pressure gauge with the sensor on the secondary filter, this will show me what pressure the fuel pump is getting. To do this I needed a set of wires to the rear of the coach, I looked for 2 days with no luck. Finally just decided to run new but to do this I pushed a 3/4" pvc conduit pipe from front to back, had to take one ceiling panel off to help guide it, what a pain but finally got it pushed through. This worked great and afterwards I also pulled a 5 wire harness back to us to install my Bluesea ML-ACR, I still have 4 wires left for future use.

So it is possible to pull wire or hosing through the rails of the coach but it ain't easy.

dale1 · 11-06-2021, 07:00 AM

thanks again.

Yesterday,

1. installed the new FASS pump. Used eshisting facotry bracket from the primary filter. "I'll post a picture later"
2. ran the 12v power source, and the return hose from the new pump to the fuel tank. "was not easy but only took about 3 hours. One man doing a two man job. "but i'm old."

I'm going locate a ignition source in the front electrical bay today.

Biggest issue i have now is plumbing the FASS return hose to the fuel tank. I can not get to the top of my tank without dropping it.

Seems like the best option is the attach the hose to the filler tube. the fill tube adapter that came with the kit is too small. I might have to Fab something up.

we missed our planned trip for this weekend

So, now i should focus on doing the job right.

I don't understand why the factory transfer pump 12v source should be removed? from what i can tell, my comes on for 30 to 60 seconds and goes off after the engine starts. no questioning, I'm just wondering.

thanks, dale

jacwjames · 11-06-2021, 07:26 AM

Quote:

Originally Posted by dale1

I don't understand why the factory transfer pump 12v source should be removed? from what i can tell, my comes on for 30 to 60 seconds and goes off after the engine starts. no questioning, I'm just wondering.

thanks, dale

I did not remove the pump, it still functions as a return mechanism for the injector pump. I did just bypass the fuel feed by removing both fuel lines and putting a union between them.

Disconnected the wiring harness and added the fooler relay, I extended the wires fro the into my rear run bay and put the relay there.

Does your run bay look like the parts page I attached, if so one of the relays already there has an ignition source along with the BIRD.

jacwjames · 11-06-2021, 07:47 AM

Surprised you don't have enough access above the fuel tanks.

For my return line I opted to use the bung hole the vent line is attached to, which is on the passenger side. This is also where the fuel sensor is located, which in most cases is a serviceable item.

This is how I opted to route my return line, using a Tee fitting, 90 fitting. Return fuel goes straight down while the vent is off to the side, figured it would allow for enough vent flow since it just needs enough to accommodate fuel usage and expansion/contraction. I've put ~5K miles on so far and all good.

Rob_M · 11-06-2021, 08:26 AM

Quote:

Originally Posted by jacwjames

Surprised you don't have enough access above the fuel tank.

I don’t have access either. Fact is, the only way I can even see the top of the fuel tank is to hold my phone over the top of the frame rail and take a picture. The front of the fresh water tank is close yo the back of the fuel tank.

I actually considered putting a trap door in the floor but the DW nixed that idea in a flash lol.

dale1 · 11-06-2021, 11:57 AM

thanks again.

Jim, after reading your post, Your right

It makes since to take the factory lift pump out of the system by way of connecting the 2 hoses together, and jumping or fooling the ECU.

yea. I don't have but 3 or 4 inches of room above the fuel tank on mine?

I finished pulling the 12v ignition wire to the front electrical box. Will attempt to locate an ignition-on source there.

I ordered the 2 inch return fuel line adapter to go into the filler tube. Just for ease of application.

We missed our trip, so now i can focus on quality vs getting it done in time. $300 and change lost on reservations for the weekend.