ruagore Report post Posted April 16, 2014 2004 Winnebago Journey with Cat 3126. Long story. Started about 2 months ago coming from California to Mesa, AZ. About an half hour into my journey traveling with the cruise set at 65mph, the check engine comes on and I loose power. Stays on for just seconds and goes out and resume speed. All gauges check OK. About an half hour later, same thing happens. . Get to our Campground and make an appointment at the Frightliner Shop in Chandler, AZ. Arrive early and start work on it. Just observing, looks like that have it hook up to the computer for at least a half hour. Shop Foreman comes by and states they want to road test. Gone for at least a half hour. Foreman comes back and tells me that the Tech cannot find any problems. Give me a bill and sends me on my way. All is well for 100 mile trip to our next stop. Now a month latter, upon leaving the campground in Cottonwood, AZ the engine light comes on and goes into the limp mode. I get off the highway, park and turn off the engine. Wait a few minutes and try and start. Will not start. Wait some more. Will not start. I have it towed to a shop. The tech hooks it up to his computer and reads the codes. He then want me to try and start the Cat. It starts....He scratches his head, looks dumb founded and states that he does not know what to do. Gives me a bill and sends me down the road. I have now relocated twice with no Check Engine light coming on. Nest trip is going to be remote. Northern AZ and NM. Almost afraid to get on the road. Anyone have any similar experience, or any Check Engine light problems? Share this post Link to post Share on other sites
wolfe10 Report post Posted April 16, 2014 Indeed, intermittent problems are hard to diagnose. But, with any electronic engine, good 12 VDC is critical. A loose or corroded connection at batteries, a loose or corroded connection at the engine ground (just below the computer on the right side of your engine) would be where you should start. Have you gone by a Caterpillar dealer to see if they can retrieve codes? Share this post Link to post Share on other sites
dickandlois Report post Posted April 16, 2014 Brett, Do the Cat ECM's log the lift pump fuel pressure at the output of the pump? Sounds like it is only showing up at cruising speeds. Did not want to start the second time, just makes me think lift pump. Rich. Share this post Link to post Share on other sites
wolfe10 Report post Posted April 16, 2014 Rich, I don't know if lift pump pressure is recorded/saved or not. A call to the Caterpillar RV Hotline could get an answer-- call with your engine serial number: 877 777-3126. Two main causes of low pump pressure-- clogged primary fuel filter and a leak anywhere between tank and lift pump. Since this is on the suction side of the system, it will leak air IN, not fuel out. Had one parked across from us last month that would not even start. Air leak in the primary fuel filter. Amazing, but diesels will not run when only air is injected. Guess they have a taste for diesel. I would be surprised that a clogged filter would give no symptoms before those experienced by the OP-- generally it starts with a loss of power at WOT (Wide Open Throttle) since this is when maximum fuel flow is needed. But, filters are inexpensive and certainly worth looking at. Share this post Link to post Share on other sites
dickandlois Report post Posted April 16, 2014 ruagore, Welcome to the FMCA fourm! Got into thinking about your issue and forgot the welcome, hope you do not think we where being rude! Rich. Share this post Link to post Share on other sites
ruagore Report post Posted April 17, 2014 OP here.....I did change the fuel filter about a month and at least 1000 miles before this started. I have changed the fuel filter on the unit at least once a year, maybe more. Always careful to fill from the outside holes till full. If by change I got air into the fuel system, will it self bleed? Thanks for the replies, Jim Share this post Link to post Share on other sites
wolfe10 Report post Posted April 17, 2014 Jim, If there is a leak on the suction side (fuel tank to primary filter to lift pump) it will not clear itself. Said another way, it will continue to suck air. Share this post Link to post Share on other sites
huffypuff Report post Posted April 17, 2014 I always give filters 3/4 to 1 turn after the gasket touches and I never have any problems. You can cuss me out when it come time to change that filter but I never had a filter leak or suck air from being loose. Share this post Link to post Share on other sites
wolfe10 Report post Posted April 17, 2014 Winn sold a rather complex primary filter "system" that was prone to leaking from the O rings around a clear plastic housing. Parker Racor has a replacement/suppression that does away with this one. Share this post Link to post Share on other sites
bm02tj Report post Posted April 26, 2014 I had a similar problem and the shop at home scanned and could not confirm trouble to absolute certainty but ask about last oil change and I was pushing 12 months changed oil and problem went away. Share this post Link to post Share on other sites
