Bad #2 Diesel Fuel?

[mark293]

I also posted this on rv.net but after at least 150 views no one wants to respond. No wonder I dont visit it often.

Anyhoo, I was returning home from an outing to Louisiana, and about two miles from home the check engine light came on in my C7 Journey. I noticed a rough idle and sluggish acceleration.

From reading alot on the forum I gathered that most performance issues are fuel related, so a couple of days later I changed the engine mounted fuel filter (dry) and the water/separator filter (dry) at the rear of the coach. I tried bumping the starter and leaving the key in the on position in hopes of priming the filters. To make a long story short, I could not get the engine to light. I decided to check the filters and to my suprise the engine mounted filter was bone dry and the wat/sep filter was half full. I filled up both filters with Power Service diesel supplement and reinstalled the filters. The Cat fired right up after holding the starter for about ten seconds and ran fine for a short trip around the block. Then the CEL came on again along with the rough idle.

My assumption is the following and I'm hoping someone may be able to confirm or advise. When I filled up in Louisiana I received some bad fuel. It took the entire trip home for the bad fuel to get in the lines and cause the rough idle/ CEL. I'm thinking of changing the filters again and dumping a bunch of Power Service,Stanadyne,Howe's, or other supplement in the tank and refueling at the Flying J just down the street.

Any words of wisdom

[Jim Stewart]

If you had gotten a tank of bad fuel and that is what caused the problem, it probably would have occurred within about the first 20 miles. If it was partially solved by the filters until they were clogged, that could explain the greater distance before the problem started.

What did the water separator filter you removed look like?

Changing the filters again is probably the least expensive diagnosis you can try. You may also have microbes (if near saltwater and humid climate) in the diesel fuel, in that case, you need to add the bio treatment to kill them and then change the filters, sometimes twice.

[Cat]

Make sure you do not have any loose fuel line fittings.Also make sure that the bowl on the bottom of the water seperator is sealing properly and is not warped.
Some driver/instrument displays will allow you to pull diagnostic codes. if you can get the codes. Get them if not. Go to a Cat dealer and get them to pull the codes.
If you can get the diagnostic codes post them and I will tell you what they mean.
Cat C7 have had problems with their HEUI pumps and also the injectors. A HEUI pump failing will give you the same symptoms you have. It can fail completely and the engine will not start or run. Good luck.

[dportem]

My baby is still in the shop. Oil pressure good but no fuel, left me hanging right in the middle of an intersection. Long story short, the HEUI pump went. We thought it was filters, but after changing them and refilling them, nothing. We even hooked up a cat computer diag. to it and no faults would show. It took it to our local freightliner and sure enough it was the HEUI pump. $1000.00 for part and 4.5 hours for service. A total ripoff, since it only took him 30 min. to replace.

[Doggy Daddy]

My DP had a large canister filter and a clear plastic micron filter. By accident I found out the micron filter could be installed upside down if one was not paying attention to the clear arrow printed on it. When it was upside down the engine would idle but the engine would fail about a 100 yards down the road when placed in gear. The filter being upside down caused a vacuum in the line.

[mark293]

The soonest I can get in at Houston Freightliner is Sept 14. Ill post the results

[dynaride99]

Mark293 Diesels are great for power but troubleshooting can take on a life of it's own. I have found that most problems on well maintained diesel engines fall under 2 categories the simple problem but hidden from view (small air leak on fitting not accessable) or the expensive part that dealers know of and have part on hand ready to go when you show up, then explain how much work they had to do. Along with the monthly morgage payment as the bill. Best advise is to visit the Cat site here and record all the Cat related problems and remedies in a log book and/or make friends with local Cat mechanic RV or Construction Company that can answer or point you in the right direction based on their repeated repair experiance with these engines.

[mark293]

The diagnosis for the CEL was a bad #1 injector. Almost funny since the title of this thread was bad#2. Almost, but not quite.

[Savannah]

Mark293

We had the same problem last winter and ended up having ALL the injectors replaced. Thankfully under warranty. No one was sure why since all had been done engine wise when it needed to be done and was done at Freightliner in Gaffney. The initial diagnosis was one injector was bad but CAT said the others were fouled by that one and should be replaced.

[mark293]

Ok, just got the call. $1500 and that includes adjusting the valves. I put in a call to CAT and they are checking my warranty status. I believe I am out of the warranty period, but I cant find documentation from the first owner for the inservice date. CAT states the moho has a clean history so they doubt I have any recourse. I might be going red next time.

[towman 2004]

Since no one else mentioned it, never install fuel filters on a C7 dry unless you have a manual priming pump located on top of the secondary engine mounted filter. If your 2004 is like mine, there is not enough clearance for a manual priming pump. If so fill the filters through the outer holes with fuel before installing them. You can put a piece of threaded pipe in the center hole to assist with filling them. You can not prime a C7 by bumping the starter or leaving the key on. That applies to Cummings engines with an electric fuel pump. There is no such pump on a C7.

Tony
2004 Newmar
330 Cat C7