jkhac Report post Posted April 21, 2019 2004 Monaco Dynasty 400 Cummins ISL engine idles fine but won't run when acceleration -- just dies back to idle -- can barely touch accelerator and get some acceleration sometimes only to die again. MotorHome has old fuel and has been recycled through filter and put back in and changed both Fuel Filter and Water Separator and Algae chemical put in fuel tank. Share this post Link to post Share on other sites
wolfe10 Report post Posted April 21, 2019 Have you checked for engine codes? Share this post Link to post Share on other sites
hermanmullins Report post Posted April 21, 2019 jkhac, Welcome to the Forum. As Brett said check your codes to start. I question your statement " MotorHome has old fuel and has been recycled through filter and put back in and changed both Fuel Filter and Water Separator and Algae chemical put in fuel tank." If it were me I would have removed the old fuel and replaced it with new fuel. I had a similar situation where I could slowly get up to speed but had no power. It turned out to be the High Pressure Pump. I also have a 2002 Monaco Dynasty with a 400 ISL. We wish you luck and please tell us what you found, it will help other that may have a similar issue. Herman Share this post Link to post Share on other sites
huffypuff Report post Posted April 21, 2019 check to see if you have a inline screen like the one inb the link below. https://www.baldwinfiltersrus.com/baldwin-pf7994-nylon-mesh-fuel-strainer.html?gclid=EAIaIQobChMIiIXgm7zh4QIVBMNkCh3EdQUyEAQYAyABEgILBvD_BwE Share this post Link to post Share on other sites
dickandlois Report post Posted April 21, 2019 jkhac, Welcome to the FMCA Forum! You should check the fuel lift pump pressure and flow rate. There is a screen in the pump and with bad fuel and age the pump could be under performing. Others asked if you have any Error Codes, but you did not mention any. Does the Engine Start up quickly? Pump Pressure runs around 10 to 15 PSI at idle. Rich Share this post Link to post Share on other sites
wildebill308 Report post Posted April 21, 2019 5 hours ago, jkhac said: 2004 Monaco Dynasty 400 Cummins ISL engine idles fine but won't run when acceleration -- just dies back to idle -- can barely touch accelerator and get some acceleration sometimes only to die again. MotorHome has old fuel and has been recycled through filter and put back in and changed both Fuel Filter and Water Separator and Algae chemical put in fuel tank. Welcome to the forum. Ok did you have a algae problem? I know about having the fuel "polished" Did you put the algae treatment in the tank before or after? You have gotten good advise, let us know what you find. Just querious, how long did the coach set. Bill Share this post Link to post Share on other sites
manholt Report post Posted April 21, 2019 Make sure your cruise control is off. If it's on, it will mimic what your experiencing! Don't ask how I know. Share this post Link to post Share on other sites
richard5933 Report post Posted April 21, 2019 Long-shot here, but does the engine have engine brakes? (Jake brakes) This happened to me once when the Jakes were set wrong. They are only supposed to engage when the throttle is in a no-fuel position. As soon as you touch the throttle the Jakes should disengage. When this happened to mine they were on all the time and would not permit any acceleration. The engine idled perfectly, but as soon as I touched the throttle the engine stumbled badly and sounded like the engine was about give out on me. Diagnosis was simple - I turned off the Jake brakes and the engine ran fine again. Share this post Link to post Share on other sites
jkhac Report post Posted April 22, 2019 16 hours ago, richard5933 said: Long-shot here, but does the engine have engine brakes? (Jake brakes) This happened to me once when the Jakes were set wrong. They are only supposed to engage when the throttle is in a no-fuel position. As soon as you touch the throttle the Jakes should disengage. When this happened to mine they were on all the time and would not permit any acceleration. The engine idled perfectly, but as soon as I touched the throttle the engine stumbled badly and sounded like the engine was about give out on me. Diagnosis was simple - I turned off the Jake brakes and the engine ran fine again. Thanks -- will check -- Only check I can do sitting still is pull up on pedal so I did that and it seems OK Share this post Link to post Share on other sites
jkhac Report post Posted April 22, 2019 On 4/21/2019 at 9:38 AM, hermanmullins said: jkhac, Welcome to the Forum. As Brett said check your codes to start. I question your statement " MotorHome has old fuel and has been recycled through filter and put back in and changed both Fuel Filter and Water Separator and Algae chemical put in fuel tank." If it were me I would have removed the old fuel and replaced it with new fuel. I had a similar situation where I could slowly get up to speed but had no power. It turned out to be the High Pressure Pump. I also have a 2002 Monaco Dynasty with a 400 ISL. We wish you luck and please tell us what you found, it will help other that may have a similar issue. Herman Thanks -- Mobil Mechanic here at our Resort has pump with filter - we pumped out one side of fuel tank side to other side fuel tank side through his filter on machine. He is coming back when he can and we'll go further with diagnostics. Will post again after that so Thanks for all the info so far. Share this post Link to post Share on other sites
jkhac Report post Posted April 22, 2019 On 4/21/2019 at 9:18 AM, wolfe10 said: Have you checked for engine codes? not yet -- maby next step when Mechanic comes back. After fuel was filtered and chemical added tried to drive and still doing same thing, so he is coming back. Share this post Link to post Share on other sites
manholt Report post Posted April 22, 2019 Do you know how to get engine codes? Share this post Link to post Share on other sites
jleamont Report post Posted April 22, 2019 jkhac, how long has this unit been parked and can the mobile mechanic pull ECM codes? When you step on the throttle, does any engine light come on or is it on already? Share this post Link to post Share on other sites
jkhac Report post Posted April 22, 2019 3 hours ago, jleamont said: jkhac, how long has this unit been parked and can the mobile mechanic pull ECM codes? When you step on the throttle, does any engine light come on or is it on already? It has been mostly still about a year maby little longer -- RV Resort I live at requires 90 day turn around (go out gate and come back in) - and I have had a couple of 100 mile trips (evacuation for hurricane) and home trip once. F'uel was added last trip and now have little above 1/2 tank. I don't know about his ability to pull ECM codes yet, will find out when he gets here. I noticed on trip little stumble on acceleration after reaching cruise speed and learned to barely easy fuel by accelerator worked,better but it always worked at cruise speed, and was towing Ford Explorer, not at lower speed kkor idle speed like its doing now. No engine lights or warnings lights have ever come on. Share this post Link to post Share on other sites
rayin Report post Posted April 23, 2019 A partially-filled tank will accumulate water due to condensation as the air in the tank heats and cools, which causes water to condense and settle to the tank bottom. The fuel polishing operation should have removed all water from the main tank, but some may remain in the fuel lines and fuel filters. Water can damage injectors if the filters cannot capture it all, which then allows water to reach the injectors. Moral - keep the tank full when in storage. If algae is in the tank/fuel system, a product like Biobor is required to rectify the issue. This usually requires multiple filter changes to capture the black gunk that remains in the fuel system. Have you changed fuel filters more than that one time? If not, I recommend doing so; then cut open the removed filter and inspect contents. If you see black goo, that is your problem. Share this post Link to post Share on other sites
jkhac Report post Posted May 23, 2019 5/23/2019 -After being towed , at Cummins South Repair Shop in Savannah, Ga for nearly a week, reported today have bad Fuel Tank causing fuel restriction. --"What" -- Waiting on conclusion of price, getting tank, and time -- Share this post Link to post Share on other sites
wolfe10 Report post Posted May 23, 2019 "Bad Fuel Tank" Would sure want to know what is wrong: Bad fuel (thought that was already addressed) Bad fuel pickup in the tank. Bad fuel hose at tank allowing air into the line. Other. Share this post Link to post Share on other sites
richard5933 Report post Posted May 23, 2019 Yeah - that is a pretty generic diagnosis. Bad fuel tank would usually mean a leak, but that doesn't appear to be the problem here. If there is sludge or other dirt causing the problem, then a new tank is not needed just a tank cleaning. Perhaps there is an applied tank liner in the tank which failed and is causing the problem? Whatever it is, hopefully the shop will provide more details. Share this post Link to post Share on other sites
dickandlois Report post Posted May 23, 2019 4 hours ago, jkhac said: 5/23/2019 -After being towed , at Cummins South Repair Shop in Savannah, Ga for nearly a week, reported today have bad Fuel Tank causing fuel restriction. --"What" -- Waiting on conclusion of price, getting tank, and time -- I had an Old truck with issues of rust flaking off inside. Resolved the issue by a though cleaning of the inside of the tank and dumping a can of a epoxy mix inside and placing the tank so all 6 sides where expose to the mix. let it set for 2 days to dry . Still working fine as far as I know - that was almost 15 tears ago. Getting the tank replaced and replacing the fuel lines might be a better fix for the coach. Yes it was a red neck repair at the time ! LOL Rich. Share this post Link to post Share on other sites
hermanmullins Report post Posted May 23, 2019 On 4/22/2019 at 1:12 PM, jkhac said: It has been mostly still about a year maybe little longer -- RV Resort I live at requires 90 day turn around (go out gate and come back in) - and I have had a couple of 100 mile trips (evacuation for hurricane) and home trip once. Fuel was added last trip and now have little above 1/2 tank. I don't know about his ability to pull ECM codes yet, will find out when he gets here. I noticed on trip little stumble on acceleration after reaching cruise speed and learned to barely easy fuel by accelerator worked,better but it always worked at cruise speed, and was towing Ford Explorer, not at lower speed kkor idle speed like its doing now. No engine lights or warnings lights have ever come on. I is never a good idea to park any type of vehicle for an extended amount of time with a half full tank. On gasoline vehicles I would alway add a fuel conditioner. On a diesel I would also add a conditioner and an algae prevention. I would have the filter changed asap. On 4/22/2019 at 9:17 AM, jkhac said: Thanks -- Mobil Mechanic here at our Resort has pump with filter - we pumped out one side of fuel tank side to other side fuel tank side through his filter on machine. He is coming back when he can and we'll go further with diagnostics. Will post again after that so Thanks for all the info so far. I can't understand pumping old fuel out one side and pumping it back into the same tank of fuel just on the other side. Cleaned (filtered) fuel will just be mixed with contaminated old fuel and be recontaminated. I have a 2002 Monaco Dynasty and unless something drastically was done you only have one tank with the ability to fill on either side Sorry just doesn't make any sense to me at all. Sorry, Herman Share this post Link to post Share on other sites
richard5933 Report post Posted May 23, 2019 When you changed the fuel filter(s) did you cut it open to see the extent of any contamination or restriction? It's quite common when dealing with sludge in the tank or other fuel contamination for there to be so much that you have to change the filter(s) multiple times. Wouldn't hurt to pull fuel filter again and put on a new one, this time opening up the filter to see what it looks like. If it's clean you'll know that the filtration was at least somewhat effective. It it's clogged you'll know that you have a continuing fuel problem. Or, you can pull a fuel sample and take it to a shop for analysis. Then you'll know exactly what you're dealing with - they will print out a report showing exactly what is or is not going on with the fuel. Share this post Link to post Share on other sites
wolfe10 Report post Posted May 23, 2019 38 minutes ago, hermanmullins said: I can't understand pumping old fuel out one side and pumping it back into the same tank of fuel just on the other side. Cleaned (filtered) fuel will just be mixed with contaminated old fuel and be recontaminated. I have a 2002 Monaco Dynasty and unless something drastically was done you only have one tank with the ability to fill on either side Sorry just doesn't make any sense to me at all. Sorry, Herman Herman, It is known as FUEL POLISHING and is very common in the marine industry. Volume and speed are high enough that it does a pretty effective job of stirring up any gunk on the bottom of the tank. And the filter(s) in the machine remove it. I know Keith Risch at MOT in Nacogdoches has the equipment and those with fuel contamination issues have reported being shocked at what fuel polishing removes from the tank. And, with the Foretravels, you can look down into the tank with a strong flashlight to verify that "all is well". Share this post Link to post Share on other sites
hermanmullins Report post Posted May 23, 2019 Brett. i could understand pumping out into a clean tank and pumping it back into the coach. Through a filter either way or maybe both ways. That way with the coach tilted one way or the other you would be able to remove almost all the gunk. JMHO. Herman Share this post Link to post Share on other sites
wolfe10 Report post Posted May 23, 2019 Do an internet search for "Fuel Polishing". The very high volume/pressure of the pump really stirs up any contaminants. Picture a bucked of water with mud at the bottom. Now, use a hose nozzle to "blast" the bottom of the bucket. And a high volume pump to remove and filter it many times. Yes, the fuel takes many passes through the pump/external filter to get the whole system clean. First hand experience in the marine industry (diesel boats have the same "storage issues" as some motorhomes) says it does work. Share this post Link to post Share on other sites
jleamont Report post Posted May 23, 2019 I recently read that there were Monaco coaches built with steel fuel tanks, they rust from the inside and that crud gets sucked up into the fuel lines. There was a couple that sourced an aluminum tank from a salvage yard and installed it where there once was a steel tank, in their driveway. Most Monaco’s the fuel tank is very simple to replace. Share this post Link to post Share on other sites
