Intermittent engine and power loss

[resqguy]

This was our first major trip of the season and about 3 hours out the Check Engine light came on and the MH dropped power and started to buck. I dropped my speed and pulled off the highway to get fuel. Driving around the area of the exit the MH drove fine. I couldn't get any truck repair places to look at the MH so I just asked one to replace my fuel/water separator. After replacing it I set out again and about 2 hours later I could feel a drop in power again and noticed the check engine, it only lasted a couple of seconds but no bucking this time. The next day it happened once again for a couple of seconds. At my next fuel stop I put in some fuel additive. It ran fine the rest of the day.

On our way home it happened once during the 8 hour trip, and again it only lasted a few seconds.

Are there some things I can check/replace on my own that would be cheaper than a trip to Freightliner? Would a repair facility be able to retrieve the error code several days old?

2004 Winnie Vectra Cummins 350.

[emiddleb]

I have the same coach, same engine. I'll give you a few thoughts with the caveat that I'm not a mechanic, just an owner who's gone through similar. There are wiser heads here who might be able to help. Having said that...

On my '04 Vectra with the ISC 350, there was only ONE fuel filter. The engine manufacturer gives the specs, but the chassis builder (with input from the RV manufacturer who's buying the chassis) add things like the fuel filters. Many other models with our engine have two filters, but as said, in my case just one.

In your post you mentioned you changed THE fuel/water separator, which leads me to assume yours is the same. And if you do a bit of Googling you'll find that the filter likely is after the lift pump. See this thread...

Motorhome Magazine Open Roads Forum: Class A Motorhomes: 2000-2004 Cummins ISC owners beware

I had a lot of issues similar issues (attributed to bad fuel) until I had my Freightliner/Cummins shop install a 2nd filter before the lift pump. Not a cheap fix but took care of a lot of issues for me. I'd suggest you have a good Freightliner shop look things over and get their suggestion.

Just my quick thought...