2001 Holiday Rambler Ambassador Starting Issues

[gnarlydavid]

Hello all - first post here, hope I am doing it right!

I have a 2001 Holiday Rambler Ambassador with a Cummins ISB300. Bought the coach last year, had the basic services done (oil change, new filters) and took it on one trip with no issues. I am trying to get it ready for a thanksgiving trip, went to start it up to get new fuel and propane in it, engine started just find and died about 20 second later. Tried again, same symptoms.

Did some google-fu, and decided to drain the fuel / water separator. Did that, symptoms persist.

Any ideas what else I should do before I call the mechanic?

Thanks

[jacwjames]

Try loosening the primary fuel filter, put a tub/bucket under to catch the fuel. Then cycle the key without starting ~4-5 times. See if fuel starts coming out of the filter, this will show the fuel transfer pump is working.

If fuel comes out tighten the filter again and then do the same to the secondary filter. If fuel comes out tighten the secondary and try to start after cycling the key 4-5 more times.

[twinboat]

Check the coolant level.

[Jon_C]

If you bump the starter the transfer pump runs for 15 seconds, if not it only runs for a couple seconds. This will purge the filters quicker

[gnarlydavid]

Hi - I'm totally down to do that, but what will coolant level do to cut off engine?

Originally Posted by twinboat

Check the coolant level.

[gnarlydavid]

How long does it generally take to purge the filters? I started ignition sequence probably more than 20 times after emptying them.

Originally Posted by Jon_C

If you bump the starter the transfer pump runs for 15 seconds, if not it only runs for a couple seconds. This will purge the filters quicker

[gnarlydavid]

Also, is there any way to tell if they are completely purged?

Originally Posted by Jon_C

If you bump the starter the transfer pump runs for 15 seconds, if not it only runs for a couple seconds. This will purge the filters quicker

[Jon_C]

On mine there are 2 plugs on top of the filter, loosen the one nearest injection pump until no more air comes out just fuel. Its an allen head plug.

[Jon_C]

Originally Posted by gnarlydavid

Hi - I'm totally down to do that, but what will coolant level do to cut off engine?

It’s possible the low coolant signal will cause engine computer to derate engine power.

[YOLOBTW]

I have a similar problem:

2001 HR Ambassdor 8.3 ISB CM550 (per Cummins Quick Serve)

Since arriving in FL I have started it 3 times. Went to start again and now only cranks.
First some history: After I first bought it, on a short trip, it started to chug and sputter a bit. After a few miles it cleared up. Didn't happen again until in TX last year. Did it a bit and cleared up. Drove all the way back to MI, used it all summer and drove here to FL. Never did it again. Even had the local truck repair check codes and such after the "warning" light came on. It wouldn't come on once I got there but they found nothing in the codes but did fix some electrical thingy that wasn't related. Now I'm parked in FL and when I tried to start it to let it run a bit (4th time), nothing. It did fire/start on the tiny bit of ether i sprayed. Confirmed. Don't need to do that again!

Here's what's been done:

New filters before coming to FL. (1200 miles)
Algeacide to fuel once here.
Talked to mechanic friend and he suggested checking/changing the filters. Ugh! But I did it.
I've cycled the crap out of lift pump to help prime before and after filter change.
2 New chassis batteries (1 was useable??, the other not)
Researched posible fixes here and on Cummins QuickServe (Excellent resource)
Removed fuel line from lift pump and cycled pump. Fuel sprays out.
Put a fuel pressure gauge on top of filter mount. When I cycle the lift pump I'm getting 14.5-15 lbs of pressure.
I'd plan to bypass the lift pump before I take it out for no reason. Waiting on Amazon for the part to do this.

I'm open to ANY suggestions.

Thanks!!

[Jon_C]

Reply to YOLOBTW:

Sounds like you lost fuel prime, even tho lift pump is pumping fuel if a bunch of air went thru injection pump after changing filters it wont start.

Not sure which motor you have, the 8.3 is an ISC, an ISB would be 5.9, different injection pumps but recovering from lost prime is same.

You need to loosen 3-4 injector lines at the head using 3/4” wrench then crank until you see fuel coming out of them, then retighten and it should start sputtering and start. Will run rough for a minute till all the air gets out.

I always prefill my filters to keep this from happening, stick finger in center hole pour fuel around outside so it gets filtered.

Not sure about the intermittent issues but sounds fuel related.

And check for any fuel leaks no matter how small, this can cause lost prime also.

Also when is last time you replaced air filter?

[gnarlydavid]

Hey Yolo- mine ended up being the injection pump. I replaced my lift pump at the same time as I read they often go out around the same time. Replaced with upgraded units from thoroughbred diesel. After replacing, it’s running like a dream. Does your still start?

Originally Posted by YOLOBTW

I have a similar problem:

2001 HR Ambassdor 8.3 ISB CM550 (per Cummins Quick Serve)

Since arriving in FL I have started it 3 times. Went to start again and now only cranks.
First some history: After I first bought it, on a short trip, it started to chug and sputter a bit. After a few miles it cleared up. Didn't happen again until in TX last year. Did it a bit and cleared up. Drove all the way back to MI, used it all summer and drove here to FL. Never did it again. Even had the local truck repair check codes and such after the "warning" light came on. It wouldn't come on once I got there but they found nothing in the codes but did fix some electrical thingy that wasn't related. Now I'm parked in FL and when I tried to start it to let it run a bit (4th time), nothing. It did fire/start on the tiny bit of ether i sprayed. Confirmed. Don't need to do that again!

Here's what's been done:

New filters before coming to FL. (1200 miles)
Algeacide to fuel once here.
Talked to mechanic friend and he suggested checking/changing the filters. Ugh! But I did it.
I've cycled the crap out of lift pump to help prime before and after filter change.
2 New chassis batteries (1 was useable??, the other not)
Researched posible fixes here and on Cummins QuickServe (Excellent resource)
Removed fuel line from lift pump and cycled pump. Fuel sprays out.
Put a fuel pressure gauge on top of filter mount. When I cycle the lift pump I'm getting 14.5-15 lbs of pressure.
I'd plan to bypass the lift pump before I take it out for no reason. Waiting on Amazon for the part to do this.

I'm open to ANY suggestions.

Thanks!!

[YOLOBTW]

Originally Posted by Jon_C

Reply to YOLOBTW:

Sounds like you lost fuel prime, even tho lift pump is pumping fuel if a bunch of air went thru injection pump after changing filters it wont start.

Not sure which motor you have, the 8.3 is an ISC, an ISB would be 5.9, different injection pumps but recovering from lost prime is same.


You need to loosen 3-4 injector lines at the head using 3/4” wrench then crank until you see fuel coming out of them, then retighten and it should start sputtering and start. Will run rough for a minute till all the air gets out.

I always prefill my filters to keep this from happening, stick finger in center hole pour fuel around outside so it gets filtered.

Not sure about the intermittent issues but sounds fuel related.

And check for any fuel leaks no matter how small, this can cause lost prime also.

Also when is last time you replaced air filter?

Thanks! First off, thanks for clearing up the engine. I have the 8.3.
Air filter is practically new
The coach was running and now won't start. I changed the filters to see if it an easy fix. I didn't prefill the filters. It looked like a 50-50 opinion. I was leaning toward filling (do this on my dozer) but that Cummins manual kept scaring me! I've bled injectors before so I will try that too.

Thanks!

[YOLOBTW]

Originally Posted by gnarlydavid

Hey Yolo- mine ended up being the injection pump. I replaced my lift pump at the same time as I read they often go out around the same time. Replaced with upgraded units from thoroughbred diesel. After replacing, it’s running like a dream. Does your still start?

Uggh! I don't want to hear this! LOL!

No, it will not start. I've been parked in FL since Dec. I regularly start it but the last time I tried it just cranked.

What did you get from Thoroughbred??