Fass pump

[Roy1]

Smitty after you installed the fass fuel pump how long does it take for the pump to prime and start pumping? I just installed a pump in mine similar to your install with the pump a few inches lower. After running my pump and turning it off for a week or so when restarting it takes the better part of a minute for the pump to prime and pressurize. This is with a full tank of diesel ? I don’t remember the original lift pump taking that long. Did you add a check valve to your fuel line and if so where?

[Smitty77]

Hi Roy1 - Never a problem waiting for fuel. By the time the Start Engine light cycle has completed, everything is good to go.

Check Valve - Will I'll double check, but pretty sure that we had a check valve in the flow from downstream from the Dual Fuel filters(?) (This is as assumption, but will take a look on Wednesday.).

Suspect you've read up on all the good info posted under the Cummins section? Here is a link, and IMO, TR4 did a great job of not only following in the footsteps of how Alan at Brazel's installed my pump - but then took it to the next level with the addition of fuel pressure gauge - which I will add, but so far it has not worked into the 'To Do!'... !

You might want to re-read this link, and see if something pop's in to help you.

http://www.irv2.com/forums/f123/repe...-289659-2.html

Best,
Smitty

[Roy1]

Thanks for the reply. Installing an electronic dash gage is something I plan on doing along with an exhaust temperature gage at a later date. I tried disconnecting power to the pump after it reached operating pressure then immediately reconnecting it when the gage read o psi. No way the fuel in the line bled back to the tank in that short time. Still took more then a minute to get it’s prime. I called and talked to a Fass tech. He felt the filters have too much restriction for the pump. He felt I should remove the first filter and use the little filter included in the kit. Not going to do that I plan on removing the 2 Baldwin filters as they may be too restrictive with too low a micron rating and trying the same fleetgard filters that are working for you. I’m surprised the original lift pump was able to get the pressure up quick and the fass didn’t.

[TR4]

My Fass pump has 16 psi in about three seconds. After sitting about nine months it might take five seconds. Cummins recommends a 10 micron filter for the secondary on my engine. I use the same two filters that Smitty uses, they are 10 micron. I would check all fuel lines from the tank to the pump (tank fuel line-primary filter-primary filter to fuel pump) for tightness. You might be pulling in air. My filters have been flowing with only a slight loss of fuel pressure for three years.
Just to be sure, you did bypass your lift pump?

Bill

[Roy1]

Hey Bill my pump is set up pretty much the same as yours but a little different due to the factory filter locations.I disconnected the factory lift pump and plugged the lines. I currently have a Baldwin bf1249 primary filter 14 micron (same as a fs1212) secondary water seperator baldwin 1272sps 2 micron ( same as fs1022). Your primary 1015 showed as water separator when I looked it up? I called Winnebago and they say I should have a primary fs1212 14-20 micron and a Secondary fs1022 2 micron . I was told a 2 micron nominal rating is 10 micron absolute? Tough trying to absorb all this for me. Did you choose a water separator filter for the primary for a reason or did your isl come that way? Fass told me I will have a problem as long as I don’t remove the primary filter and install their little metal filter? I think they said it was 40 microns. I only have 5000 miles on the 2 filters but I think I should buy new fleetguard filters and see what happens . Do you think the fs1212 would be ok ? My -10 hoses are pretty tight and don’t leak on the pressure side but hard to tell on the suction side. The line to the tank should be good as it started easily with the stock lift pump.

[TR4]

Roy1,
I’m using the same filters that Country Coach used. Your primary filter (FS1212 or BF1249) are 20 micron, where my FS1015 is 10 micron. So, your filters should flow better.

After your start lights have cycled (aprox 3 sec), will the engine start?
Have you checked fuel pressure after the secondary filter? There’s a port on top of the secondary filter where you can install a fuel pressure gauge.
Did you have starting problems before the Fass install?
How did you determine the Fass pump was taking so long to prime?
After the Fass install, did you have the priming problem, or has just started?
Do you have a fuel shut off valve on the primary filter in the wrong position?

As I said, my filters are over three years old with over 15k miles. The Fass has run with zero problems since the conversion. I would start by doing a fuel pressure reading, then change the filters and do another reading.

Bill

[Roy1]

Bill: haven’t tried to start it yet, didn’t add a gauge to the port in the secondary filter yet but that is where I will connect it for the dash gauge when I get to it.,always started easily, have a gauge installed in the fass pump timed with a watch, timing problem started with the fass install, the shut off valve is open not closed. I agree I plan on ordering the fleetguard filters today to see if it makes a difference the pump sounds ok once it primes it was holding a steady 15 lbs I didn’t try starting the motor when the dash lights went out figuring it wouldn’t till the pump primed but maybe with the injection pump sucking? At any rate I don’t want to hurt the injection pump. My rig only has 20,000 miles on it some folks do that in a year.

[TR4]

So, you’re saying it takes more than a minute to show pressure at the pump? That doesn’t sound normal. You could run a hose into a bucket off the outlet on the secondary filter and check for bubbles. Make sure filters are tight and water drains closed. Could also be an air leak on a defective Fass pump. Start with the filters.

Bill

[Roy1]

I agree 2 new filters should be the starting point.

[Roy1]

The new fleetguard filters weren't any different then the Baldwin filters . I cut one open and it was in like new condition. Pressurized the pump suction side fittings no leaks. I found if I cranked the engine when the dash lights went out the cap pump started sucking and the fass pump was instantly primed. I am going to call this good I guess the fass pump just needed a little help to get primed.

[Smitty77]

Instead of turning the engine over. Have you tried doing two compete Wait To Start cycles?

In not too cold, say mid 30's, instead of using my Hydro Hot Pre Heat Loop, I go thru tow full Wait To Start cycles, to let the preheater do it's thing. And seems to start a bit easier then when I only do one Wait To Start. (In the low 30's and below, I do use the Hydro Hot Pre Heater to give us a better shot of an easier start. Especially when on 50A supply, I'll turn on the Pre Heat when I'm up for 'other reasons' during the night anytime after 2:30AM. And the Electric element of the Hydro Hot does a good job on supporting that. (If it's real cold, and we're not on 50A but boon docking, we usually have the Diesel Burner on for heating anyways, and it supports both out heating needs and the Pre Heat of the engine without any problems.)

I'm just curious if you did two Wait To Start cycles, if that would help prime the system for you?

Best to you,
Smitty

[Roy1]

I don’t have a hydro hot . When I first installed the fass pump I didn’t connect it to the ignition circuit . I just powered it with 12 volts and timed how long it took to prime. I am positive I don’t have any leaks on the new fittings. With it wired to the ignition as soon as I crank it the pump is instantly pumping. If I do multiple wait to start cycles each time the pump will take the same amount of time to try to prime but it will be pumping as soon as the engine starts cranking. Thanks smitty.