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CampoutWill · 05-18-2023, 12:57 PM

Good afternoon everyone my name is Will from South Florida. I have a question my 2002 Holiday Rambler Ambassador with a Cummins 8.3 ISC 315hp was running rough on my way home from South Carolina. Long story short I had the engine scanned at a local truck repair and they told me that the accumulator needs to be replaced. Question is this something that normally goes bad? Could it be that it just the accumulator and not the injection pump? I noticed leaving the shop while running rough it through out white smoke. The fact that the accumulator is bad could that have damaged my injection pump? I had a leaking lift pump replaced roughly a year ago and have driven roughly 3,000 miles without any issues until now.

Will

Skip426 · 05-18-2023, 01:08 PM

Your 2002 ISC ; has the CAPS fuel injection pump ( Cummins Accumulator Pump System ) .
The accumulator is part of the injection pump .
Did the shop give you a price on the repair ?
Was the price for a new or exchange CAPS injection pump ?

Air entering the CAPS pump from a bad lift ( primer ) pump, could have damaged the accumulator and the full extent of the damage took a while to show up.

Here's some info on the CAPS system.

CampoutWill · 05-18-2023, 01:29 PM

I was quoted roughly $2,500 parts and labor with original cummins accumulator. Codes are 0456, 0434, 0381 and 0141 they claim it's just the accumulator but I didn't sense confidence in any of the responses I got from them .

Will

Skip426 · 05-18-2023, 01:38 PM

I have a file on the CAPS system ; that is too large to post to iRV2 .
I'll read through to see if the codes are listed , and to see if the accumulator can be swapped out without removing the entire pump from the engine .

The $$$ seem low as a complete pump is usually double that price + installation.

jacwjames · 05-18-2023, 03:11 PM

0434>>Supply voltage to the electronic control module (ECM) fell below (+) 6.2 VDC for a fraction of a second, or the electronic control module (ECM) was not allowed to power down correctly (retain unswitched battery voltage for 30 seconds after key turned off).

0141>>>High voltage detected at oil pressure sensor signal pin 33 of the engine harness. ASSUMING you have an oil pressure sensor instead of switch

0381>>> Error detected in the cold-start air relay 1 enable circuit at pin 41 of the original equipment manufacturer (OEM) harness.

0456>>> Fuel Pressure Sensor Circuit. Fuel pressure sensor stuck in range while engine is operating or fuel pressure sensor reading erratic in range.

All of this was found on the Cummins Quickserve site, you can create and account and register your engine and get access to an enormous amount of info. I used the fault code look up to find the above info. In each case there was more info on how to troubleshoot and fix.

Most of the above has to to do with wiring. Check your battery connections. I'd check the connection of the wiring harness going to the ECM. On my 2002 Windsor I have 4 fuse holders in my rear passenger side, I'd check all those fuses making sure there is no corrosion and fuses are seated tight. , most have to do with engine, diagnostics etc. One is for the transmission.

CampoutWill · 05-18-2023, 03:48 PM

I originally thought I had a transmission issue when leaving Myrtle beach and headed to South Florida. I started the engine up after being in the campground for a week and a half. The check transmission light lit up on the dash and the transmission wouldn't go into gear . After a while it finally went into gear and I started the long drive home. Later on the coach had a hard time staying in 6th gear, it felt as if the transmission was running on limp mode but was getting progressively worse. As I would slow down the coach had a hard time getting back up to speed. When I finally made it home I realized the batteries were bad I think a lot of the voltage codes were stored from when the batteries were bad. According to the mechanic he cleared them and the 2 that keep coming back are 434 and 456.

jacwjames · 05-18-2023, 06:47 PM

Low battery voltage can affect the transmission and engine. I'd fix that problem first and then work the rest of them. The fact that your motorhome was/is running is good. Most problems with the CAPS injection system leave you dead in the water.

The accumulator for my injection pump is ~$1600, not sure I've ever seen where someone has replaced it.

Skip426 · 05-18-2023, 06:58 PM

Thanks Jim , for posting the additional info on the codes , probably like you I'm having issues going from the codes set ; to a failed accumulator .

Your recommendation to chase down the voltage issues is spot on.

I'd also forgotten about the four inline fuses in the vintage Cummins wiring systems .

Will , even though the batteries are new you need to check the wiring connections at the batteries and locate the inline fuses . Caustic fumes from the bad batteries may have damaged the wiring and result in the low voltage codes from the ECM.

CampoutWill · 05-18-2023, 07:29 PM

Ok guys thanks for all the replies, I will check the fuses on the wiring, the engine doesn't shut off on me but seeing that smoke today scared me , do these symptoms sound like a bad injection pump?

Will

jacwjames · 05-19-2023, 12:32 PM

The CAPS injection pump is a known problem but like I mentioned earlier, most of the time it will just shut you down and the engine won't start. A couple people have been successful changing some parts on the CAPS pump but not many and they had decent/good mechanical skills.

Since your engine is running and it's not throwing a check engine light or stop engine, that's a good thing.

Your problem seems to be intermittent and pointing to an electronic problem, bad connection.

Really need active codes to know what's going on. You might check on getting a code reader and or an engine monitoring system like Scangage, Bluefire, or Silverleaf.

I've seen posts of people getting a scan tool from Harbor Freight that is suppose to support Cummins Engine, I cannot confirm personally though.

If you can get codes you can then use the Cummins Quickserve site to troubleshoot. https://quickserve.cummins.com/info/index.html

Have you changed you fuel filters, you could try that. If you were in FL you might have got bad fuel or if you were parked for a while an algae growth.

jacwjames · 05-19-2023, 12:41 PM

Here is a picture of the electrical compartment on the rear passenger side of my coach.

This is where the 3 fuse holes I mentioned that hold fused for the engine, ecm, diagnostics and one for the transmission.

I would check each fuse and then if you reach the wiring harness on the ECM check it. The ECM is on the passenger side of the engine, hard to reach but doable. Do a visual check and the check to make sure it is tight.

One of the fuses is what provides power to the ECM.

Also check your battery connections.

Skip426 · 05-19-2023, 12:53 PM

Jim; a question ; because I've never been hands on with the CAPS injection system . (I've had Cummins training on the four injection systems used on the Dodge/Cummins 5.9 and 6.7 over the years.)

Could an issue with the " transient suppressor " or it's wiring, contribute in any way to the fault codes being generated ?
Or is my understanding or the suppressor's function ; way off base?

CampoutWill · 05-19-2023, 01:19 PM

I checked the fuses and all were fine. All I have left to check is the ecm harness to see if it got loose, crazy thing is the coach was running so sweet on the way up to South Carolina smooth as ever I don't have a clue what this is . I changed my fuel filters last year they have maybe 3,000 miles on them at most. I searched if smoke is possible with clogged filters and came up as no? Would it smoke if the filters are clogged?

Will

CampoutWill · 05-19-2023, 01:31 PM

Also the coach starts with no issues idles fine but only during acceleration does it hesitate jump and I have only seen it smoke once during acceleration.

Will