Total loss of power

[scoutmstr]

I have researched this site for all related type failures before this post. My 12/03 chassis W-22 has had total loss of power four times over the five years I've had the coach. (Bought new) Twice was in the same day. Three of the four times was on flat roads and two of the three were on the interstate. Luckily I was in the right lane all times and never in the middle of a city. Yesterday was the last time headed east on I-10 right where I-8 intersects. I've taken the coach to Alaska for two months in '05 and Canada for two months in '08. Never any problems there. All four happened in AZ, three in the summer. The failure is immediate, not limp mode or reduced engine and will not respond to throttle. After coasting to a stop the engine will restart in 30 seconds and continue as if nothing has happened. I had always believed it was electronic until yesterday. Shortly after the failure I stopped for gas although I still had 3/8 tank. When I removed the gas cap the pressure almost blew the cap out of my hands. So somehow (yet to be determined) the return line is pressurizing the gas in the tank to a vapor state and I believe the coach is experiencing vapor lock which I didn't think could occur on a FI system with the pump in the tank.

["007"]

You should have a vent tube that follows your gas tank fill line. Its either plugged with fluid or maybe something has crushed tube or vent tube has fallin lower than fill tube.

[Breezeman]

Hey Scoutmstr,

Not sure if this will help or is related but I have had the same issue. Last year middle of summer heat in Florida going home RV just shut down. Pulled over restarted and continued another hour or so and died again. This time would start but struggled to stay running. Called roadside service to come out. We changed fuel filter and made it on home. Seemed simple, right?

This summer on same trip, same thing happened twice. But restarted and made it home. SO, I decided to change my (in-tank) fuel pump after a lot of reading here on this site. Turned out that the filter connected to the actual pump was about 80% clogged. Also put on another new fuel filter that is attached to frame.

I have only been on a few short trips, but so far things seem to be OK. Also seems to run a little smoother and more responsive.(could be a mind thing also)

Hope this helps.

Larry

[George Z]

Quote:

Originally Posted by Breezeman Hey Scoutmstr, Not sure if this will help or is related but I have had the same issue. Last year middle of summer heat in Florida going home RV just shut down. Pulled over restarted and continued another hour or so and died again. This time would start but struggled to stay running. Called roadside service to come out. We changed fuel filter and made it on home. Seemed simple, right? This summer on same trip, same thing happened twice. But restarted and made it home. SO, I decided to change my (in-tank) fuel pump after a lot of reading here on this site. Turned out that the filter connected to the actual pump was about 80% clogged. Also put on another new fuel filter that is attached to frame. I have only been on a few short trips, but so far things seem to be OK. Also seems to run a little smoother and more responsive.(could be a mind thing also) Hope this helps. Larry

Good information. Thanks

George

[DonavonP]

Quote:

Originally Posted by George Z Good information. Thanks George

I'll second that.

[scoutmstr]

Thanks for the inputs. I think it is heat related due to the pressure in gas tank but I will check out all the fuel system including pulling the fuel pump. Thanks to Rexhall there is an access hole through the bottom of the compartment right above the fuel pump. Maybe then I can get a real non WCC part number for for that pump. If so I'll post it.

[scoutmstr]

As I was sitting here rereading my post and the thread especially 007's input, I remember in '05 losing my gas cap and buying one in Whitehorse at NAPA. Is our gas caps vented or nonvented? If it is nonvented how does the system deal with vapor pressure. I remember carb engines had charcoal cannisters but what does FI engines have?

[DriVer]

Quote:

Originally Posted by scoutmstr Is our gas caps vented or nonvented? If it is nonvented how does the system deal with vapor pressure. I remember carb engines had charcoal cannisters but what does FI engines have?

Our fuel system is closed non-vented system. Any fuel vapors are trapped by the canisters and subsequently burned. That's it.

[tderonne]

There should be a pressure relief somewhere in the system. Often it's in the cap. I can't recall for sure but I think the typical pressure relief is around 12" of water.

I'd check into exactly what the OEM cap was, and what you have on there now. If you have a ScanGauge or other OBDII device, you should be able to find the Fuel Tank Pressure (FTP) somewhere.

[DriVer]

Quote:

Originally Posted by tderonne There should be a pressure relief somewhere in the system. Often it's in the cap. I can't recall for sure but I think the typical pressure relief is around 12" of water.

According to our owner's manuals on page 160, 2006 Owner's Manual. (same as others) the directive for the cap is to turn is slowly to the left counterclockwise.

What this does is to allow pressure in the tank to be bled by the thread space in between the cap and the filler neck on opening in the event a pressure condition exists.

I don't believe that there is a pressure relief device in the system because that would vent gasoline vapors into the atmosphere which is not legal under California emissions and other statutes on the book regarding gasoline powered vehicles.

Vapors are trapped and burned. With the returnless (2004 & better) fuel system, the pump always runs in a closed loop and it will by-pass the fuel back and dump it back into the tank. I can't speculate how pressure would be allowed to increase in the fuel system and become trapped to the point where it over pressures the fuel system. The fuel line going to the rail has a bleeder right on top of it on top of the engine. Once the pressure is relieved there the damper can be replaced if one needs to have the clip recall done. One need use caution there as gasoline should not be allowed to be ejected on the hot engine.

What we've seen here so far suggests that the best remedies are to rule out a plugged fuel filter and lastly the sock on the pickup tube in the fuel tank itself.

[speed racer]

The vapor recovery canisters are meant for just that "VAPOR". There are times when they get liquid in them(gas from over filling the gas tank or water from driving through water or a lot of rain)and they can no longer vent the vapor and cause a build up of pressure. when the pressure gets above a set amount it will turn the check engine light on but it won't cause the engine to quit. The older models could be serviced but the newer ones have to be replaced. If It was mine I would look in the area of the ignition switch. They did have problems with them.

[scoutmstr]

I did pull the fuel pump module which thanks to Rexhall only involved six screws and a carpeted sheet metal plate over the gas tank. The tank looks clean, the socks look clean. With help I can post pictures of the module. There is a paper tag on top of the module with the following numbers
40G8860
725352-2
1183-5R
08-15 (?)

Down in the canister thereis a casting number of

25174532
P81P-GF-15

So far no luck from Chevy or internet in finding out whose numbers these are.

Also on the pump motor itself is a number 990.

When my third member was replaced two years ago the service facility (Echols in PHX) was modifying module cannisters because of heat soak on the pump motors. They did this by drilling 6 1/2 holes into the plastic cannister to allow more fuel around the pump motor. They also said that Workhorse newer modules had this modification.

[scoutmstr]

After spending all morning on this, I called Workhorse and talked with the technical people. They told me the Module I had was subject to some overheating of the pump because it was inside the plastic cannister. What they had done on later versions is to make the sock on the motor extend through the side of the cannister for cooler fuel which is similar to what Echols RV told me. Researching more on this webiste I came across this post from parts experts in reply to one of my posts

Quote:

you're confusing yourself here... the 25178125 supercedes to 25315352. This works on most 2002-2003 W22s. the 25178145 works on 2001 W22s. Prior to 2001, there were no W22s. I will say that the 25178125/25315352 were used on prior 350-powered P42 vans with 40 gallon tanks. as of right now, both (25178145 and 25315352)are still available

With that in mind I now understand some of the numbers I found on my pump. See previous posts. The 40G actually stands for 40 gallon. With my pump now out. I checked all Delphi fuel pump modules for a configueration like mine especially for the connector on top. The only two I could find (FG0258 and FG0305) that appear to have a connector like mine are now obsolete. However, I found the following website " http://www.rustrepair.com/STEPVAN_PARTS/onlinecat.htm?r=fr&p=WI-FUEL-GAS.GMT-81811" who has the exact same fuel pump module for Workhorse for $219 through 9/30/09. I'm sorry for the long post but I wanted to get all the information out since I've been looking for a non-Workhorse supplied fuel pump for a couple of years.

BTW, my lack of power situation appears to be a Rexhall caused problem in that they routed the gen fuel line over the top of the EGR cans which get hot. I believe this causes the fuel in that line to vaporize and pressurize the vapor back into the gas tank resulting in the pump trying to push vapor when the tank is less than 3/8 full and temp is over 100