'99 RE 8.3L Cummins last started around Oct '18

[Brewerbob]

Originally Posted by cadillackid

is that a straight motor pump or is it driven by a PWM signal?

Not much on it in the service manual but it says it's driven by the ECM.

Originally Posted by joeblack5

It looks toe that it is an electromagnetic membrane . pump. If you connect it to the battery it should make a click. Then you release it and make the contact again..

While jumping it, I was standing next to it making sure the wires were making contact. Nothing. No clicking, no vibration.

So test some more before you spend a couple of hundred bucks..

Already ordered it. $215 from some place in OR.

It looks like a low pressure transfer / lift pump. So you could replace it for a low grade fuel pump to at least get fuel to your IP and get the bus started..

Way too many lines in and out of that thing.

Good luck
Johan

Thx.

[Bon Voyage]

The lift pump is loud, sounds almost like a buzzer that runs for 30 seconds when ignition is turned on. Hopefully that’s the problem. Don’t crank the engine till you know for sure the lift pump is putting positive pressure on the caps pump. That caps pump will fail if starved for fuel and is very expensive to fix.

I put a pressure gauge in my lift pump manifold on the output side to show pressure. It’ll be a cheap easy way to see if you’re getting positive pressure out of the lift pump. I’ll try to post a picture tomorrow.

[TJones]

The better fix for the CAPS lift pump is to replace it with a low pressure aftermarket pump like a FASS and set it to 5 to 10 psi. The constant low pressure ensures the CAPs injector pump always has a supply of fuel and pushes a little extra fuel through for better cooling of the injector pump. Lots of info on this in the RV forums CAPS failures seem to be pretty common.

A FASS pump, pressure gauge and Davco filter are my fuel system upgrade plan.

Ted

[WIbluebird]

Originally Posted by TJones

The better fix for the CAPS lift pump is to replace it with a low pressure aftermarket pump like a FASS and set it to 5 to 10 psi. The constant low pressure ensures the CAPs injector pump always has a supply of fuel and pushes a little extra fuel through for better cooling of the injector pump. Lots of info on this in the RV forums CAPS failures seem to be pretty common.

A FASS pump, pressure gauge and Davco filter are my fuel system upgrade plan.

Ted

This is my plan as well. It appears that they sell a kit for a small low output pump that screws into the OEM filter housing?

[Bon Voyage]

I have to reteach myself how to upload photos on here every time I do it because I don’t do it very often. Hopefully they’re not sideways.

Anyway here is the gauge I put on the lift pump manifold to monitor pressure to the caps pump. There was a threaded plug I pulled out (just like the one to the right in the first picture) and it screwed right in. The gauge was like $20 or something. Just make sure you’re getting positive fuel pressure on this side of the lift pump before you start cranking the engine. If it starts the pressure will go negative after the lift pump shuts off as the caps pump will start sucking the fuel.

The second picture is my fass pump which the others just mentioned, they’re a better option than the stock lift pump because it keeps positive pressure on the caps pump all the time; it’s a bit of a long story but I’d highly recommend you look it up and get one if you’re committed to this bus.

Edit: the top picture is straight and the bottom one is sideways

[musigenesis]

Convert your pics to PNG format and then upload them - no rotation issues.

[TJones]

Originally Posted by WIbluebird

This is my plan as well. It appears that they sell a kit for a small low output pump that screws into the OEM filter housing?

I have not seen that kit. From what I've read on the RV forums is that you install an after market lift pump and bypass the OEM pump. You then need to unplug the OEM pump and attach a certain size relay to fool the ECM into think that the lift pump is working.

Ted

[Brewerbob]

Originally Posted by Bon Voyage

Anyway here is the gauge I put on the lift pump manifold to monitor pressure to the caps pump.

Do you have links for the pump?

[Bon Voyage]

You could install a FASS (fuel air separator system) pump or a diesel pump without the air separator in. That's what I was going to do but in the end the FASS system just seemed easier.

Here is the link to the pump Fass recommended; its a generic pump for many different applications:

https://fassride.com/shop/product/fu...gph-universal/

This is a link to the one I bought because it came with some extra fittings and brackets that came in handy for the install though I still had to buy some things. This is the same pump as the one above but its a kit with the parts designed for easy install on some Dodge trucks:

https://fassride.com/shop/product/fu...-d07-100g-kit/

Lastly here is a link to a motorhome forum where this topic is discussed at length for the 8.3 Cummins with the CAPS injection system - years 1998-2003 I believe...

https://www.irv2.com/forums/f123/rep...289659-19.html

[Brewerbob]

Originally Posted by Bon Voyage

You could install a FASS

Thx!!

New pump is here. Going to try to get it replaced tomorrow.

[Brewerbob]

So, for the most part, I've got the pump replaced. The smaller flange plug stripped trying to get it out. Without the plug, I can't even test it. Tomorrow's goal is to find a plug.

[cadillackid]

gotta love people that honk down on NPT fittings and threads... almost always makes it impossible for someone to service later..

[TJones]

I do hate NPT fittings I much prefer O-ring boss, JIC, flat face O-ring or anything that has a positive seal that doesn't require thread sealant.

Ted

[cadillackid]

Originally Posted by TJones

I do hate NPT fittings I much prefer O-ring boss, JIC, flat face O-ring or anything that has a positive seal that doesn't require thread sealant.

Ted

yeah me too.. tapered threads will never feel "tight" to some people so they honk down as hard as they can.. well of course after the sealant hardens and the metals really mate in that fitting aint comin out of there.. and in my experience it doesnt take a huge amount of torque to get them to seal with the proper sealant..

[Brewerbob]

Well, ... that didn't work. Still not priming the fuel filter. Anyone know exactly where the relay is? There are a couple of them and a **** ton of connectors in the engine bay.

[Brewerbob]

Originally Posted by cadillackid

gotta love people that honk down on NPT fittings and threads... almost always makes it impossible for someone to service later..

Turns out it wasn't NPT. The big fuel hoses (rubber) are straight thread. The steel fuel lines on top were NPT and they didn't give me any trouble.

[Brewerbob]

All I need is one of these... it's only $1377 from Cummins.



https://store.cummins.com/#/model-detail/5299899/buy

Found an older version, better price but still a little pricey just to read codes once.
Cummins diesel engine 4918416 inline 5 diagnostic tool datalink adapter
Reference Price $ 688.95 - 709.92

[Bon Voyage]

That’s not a regular code reader is it?
Couldn’t you get a mobile mechanic come out to do it for a lot less than that?

[musigenesis]

On an International there's a little button next to the data port you can press and the dashboard will indicate any codes by blinking the engine warning light in sequence. Do BBs not have something like that?

[cadillackid]

bob.. thats a rebranded RP1210 device.. its a Nexiq rebrand..



same as



https://www.hobdii.com/wholesale/nex...RoCkfQQAvD_BwE


I have the insite software and a nexiq Device but have never used it before as i dont have a cummins vehicle..