Priming capps pump help please

[whitetop]

So I just got my capps pump installed and would like some advice on priming the pump. Thanks for any help.....

[jacwjames]

Your Imperial should be very close to my Windsor.


The filter on the drivers side of the pulley end of the engine is the primary filter, I'd install a new filter, find a plastic plug that will fit in the center hole, pour new fuel into the filter through the outer holes. Install the filter.


I would cycle the key ON/OFF to times without starting, this will turn the lift pump on/off and hopefully pull new fuel from the diesel tank through the primary filter.


Now remove the secondary filter on the passenger side of the engine and fill as you did with the primary.



Cycle the key another 10 times ON/OFF


The try and start the engine.



If it doesn't start try cycling the key on/off again.



Try starting again.

[whitetop]

Thank you, Sir. You always have the correct answers.

[jacwjames]

FWIW
My transfer pump started leaking in 2020, I tightened the 3 bolts on top as a stop gap fix. Then after looking at options I decided install a FASS transfer pump and bypass the original transfer pump. I also installed a pressure gauge to show what the FASS is doing. I did leave the secondary, water seperator filter, in place.



Now when I turn the key on I see 16 psi of fuel pressure. The FASS pump runs continuously with the excess fuel pumped back to tank after going through the filters. This is basically polishing the fuel, I've changed the filters a couple times. The first time I saw quite a bit of stuff that got filtered out.

[Lowflyer1]

That era Holiday Ramblers are set up a bit differently from the Monacos. The lift pump runs for approx. 1 minute with the ignition on.
So you turn on the ignition for ~1 minute & then ignition off.
Repeat this a number of times.


You can hear the lift pump running if you are by the engine while assistant is cycling the ign. key.

[shootist]

Originally Posted by whitetop

So I just got my capps pump installed and would like some advice on priming the pump. Thanks for any help.....

You state that you replaced the caps pump ? Do you mean the lift pump? If in fact you replaced the caps don't start it until you know the lift pump is working and you also should have replaced the transient voltage suppressor.

[whitetop]

Thank you. Yes, I installed the CAPPS pump, and suppressor. The lift pump is working fine. Currently waiting for the upgraded wire harness, due to a fuel pressure sensor upgrade.

[jacwjames]

I had a fault code in 2023 for the pressure sensor. When I took the sensor out the wiring harness was in extreme tension, could barely get the harness apart. Could not find anything wrong with sensor.

I looked up the part number and it had been superseded showing a new part with a harness support. I even called around to try and find the new part but none anywhere.

My guess was that the fault code was caused by intermittent wiring issue caused by the wiring harness being almost pulled apart.

So I put it all back together and then used zip ties to help support the harness.

That solved my problem, finished my trip and when I got home did a better job of supporting the harness.

[wolfe10]

If you have a helper, it is easy to determine when you are primed and exactly how long the lift pump runs.


The helper does nothing but turn the ignition key to ON (not all the way to start, just to ON) when you tell them and OFF when you tell them. A clean, no strain job!


Your job is little more stressful. You are standing or sitting behind the passenger's side rear wheel where you can hear the lift pump run (and when it cycles off). Based on this, you can tell the helper when to turn the key off and back on.


Also easy to tell when the system is primed. High speed sound from the pump= pumping AIR. There will be a very distinct change in RPM and sound when the air is gone and you are primed.


If 10-20 cycled do not prime it, you have another issue, like air leak at fuel filter, cracked fuel hose, etc.