DaveAtherton

Lloyd, First question does your fuel filter have a hand primer pump? If it does see if it is hard to push in-- is should be. If soft/easy to push, there is air in the system. If answer is yes "it is hard to push", than open up engine cover under bed and go to rear of engine (foot of bed/toward front of coach). There is a hex fitting about 3 inches long on elbow coming off rear of cylinder head at 45 degree facing passenger side of motorhome. There is a hose connected to this hex fitting. The hex fitting is the fuel pressure regulator that holds diesel fuel in cylinder head. The fuel pressure regulator has a check valve and diesel fuel fines if setting will stick the check valve. Remove hose connected to the regulator and turn engine over to see if fuel comes out and in most cases engine will start. The hose that I am talking is the return fuel hose going back to fuel tank in front. We need to know for sure that when turning engine over by key that diesel fuel passes out the back of engine head. Note: if fuel does not come out of check valve engine will not start. This is very common problem with Diesel fuel fines ( not using Cat OR-0751 2 micron fuel filter and/or fuel filter needs replaced). Last: bad diesel fuel. Have chased down no start but engine turns over as a electrical problem and has ended up with fuel pressure regulator on rear of cylinder head. Might look this area over real good. Dave Atherton Retired Cat Mechanic

Good morning, following post about low power, ISL / ISC with caps system. Post on probem on right track to correct problem. Caterpillar has had same problem with Heui injection systems with constant fuel flow in motorhomes being fuel tank location 35 to 40 feet from engine and a singe stage piston type fuel transfer pump pulling fuel. Along with all this being said not taking in any air leaks on the suction side pulling fuel from front. What has been mentioned is correct on tract except need to remove Cummins electric pump from system and go direct to caps pump. Caterpillar Update same problem on 05/02/2005 (Special Instruction). Instruction for installation for electric fuel priming pump on caterpillar equipment. This includes COMMERCIAL ENGINES AND TRUCK ENGINES. The caterillar electric fuel pumps runs anytime engine running to provide constant fuel flow from fuel tank. Good example Cat C-9 400 HP has a single stage piston fuel transfer pump along with age and other factors air entry cannot meet the demand of constant fuel flow and maintain constant fuel pressure. The idea is great and there are several Caterpillar owners that have gone this route with great reviews. With Cummins engines same concept remove electric pump that only runs for 30 seconds and install a electric pump that runs all the time. Without any fault codes or event codes on low power is telling a person basic there is not a problem when there is a builder problem putting a fuel tank 35-40 feet away and expect to maintain constant fuel flow. Dave AthertonRetired Cat Mechanic

Gentleman, coming in on this problem and answering to above post . Checking turbo wastegate arm and Rod movement is there is full range of movement. Next move I would suggest with low power is the fuel system from fuel tank to engine, which a temp bypass was made. Did you check fuel pressure going into the engine fuel rail 60 to 65 psi high Idle. Being fuel transfer pump rebuilt you should but needs to be checked ( low fuel pressure will cause low power ). Next place to look real close at is the fuel pressure regulator on the back of head, in time the check valve will not hold back pressure in fuel rail. Connect a clear plastic hose to the return to fuel tank hose on discharge end of fuel pressure regulator for clear stream of fuel coming from engine while engine at idle and high idle. If you have lot of air or foam in fuel clear line returning to fuel tank than that would cause low power. Dave Atherton Retired Cat Mechanic

Good morning gentleman, I guess term MAT Sensor comes from terms other than Caterpillar tech info. Term that I am going to go with boost pressure sensor which is part of group of 5 volt sensors. The voltage with this sensor group is strict 5 volt power range. If any of the of group diagnostic code share active 232-03 5 volt supply above normal and 232-4 5 volt supply below normal. What this is telling problem is a wiring or pin terminal problem. Do not replace the sensor or ECM. Note: if the sensor has an integral connector the pin Connector cannot be removed. Only replace the socket terminal in wiring harness. My suggestion before going into depth on problem first check the turbo wastegate for movement, check little rubber hose that actuate the wastegate Rod. Last note: do not try to induce power to the 5 volt sensor group because the sensor group is all tied in together and go direct to ECM unfuse. Dave Atherton Retired Cat Mechanic

Gentleman, Use the diagnostic lamp to determine diagnostic flash code. Use the following to retrieve diagnostic codes if engine with a diagnostic lamp: First turn cruise control On/OFF switch to The OFF position. Second move the SET/RESUME switch to either position. Hold that position until the yellow lamp begins to flash. Note: the YELLOW lamp will flash in order to indicate a two digit flash code and SET/RESUME switch may be released. The sequence of flashes represents the system diagnostic message. Count the first sequence of flashes in order to determine the first digit of diagnostic code. After a two second pause, the second sequence of flashes will identify the second digit of diagnostic code. Any additional diagnostic codes will follow after a pause and will be displayed in the same manner. Flash Code 55 signals that no detected faults have occurred since key switch was turned to the on position. Troubleshooting is not required for codes 35, 41, 47 and 55. Codes that will shut engine down, Injection Actuation Pressure sensor Code 17 Injection Actuation Pressure Control Valve fault. Code 18 Engine RPM Signal Fault. Code 34 Intermittent Battery Power to ECM. Code 51 High Coolant Temperature Warning. Code 61 Low Coolant Warning. Code 62 Ignition Key fault Code 71 Whenever the Electronic Control Module ( ECM ) detects an active fault or condition the lamp will flash at five second intervals. If the lamp turns on and if the lamp stays on after initial startup, the ECM has detected a system problem. The Diagnostic lamp is also used for the idle Shutdown timer. Lamp will start to flash at a rapid rate 70 seconds before the programmed idle time expires. The engine will down after 70 seconds after a 70 second interval. To disable the idle shut down timer, the clutch pedal or the service brake pedal must be depressed during the event 70 seconds while yellow lamp is flashing. A diagnostic EVENT code or Override of the idle shutdown timer will be logged in the ECM. Dave Atherton Retired Cat Mechanic

I can help you with location of sensors for cat C-9 engine, first of all what is engine S/N. Second will need a e-mail address to send you sensor info. Use the "Send message" feature so your personal information is not compromised. Just over over "DaveAtherton" then click on "send message". Dave Atherton Retired Cat Mechanic

Lucky dog 1949, we can go around and around with milage. Unless you can plug Cat ET into your engine ECM and readout trip data off ECM a person is only guessing. Doing diesel Diagonostic work I read out many,many engine ECM On both Cat and Cummins engines. What the finding on fuel milage will run from 6.5 mpg to 8.5. mpg. This is engine only and not taking in genset running. Cummins uses same readout using Insite and milage is same as above. Dave Atherton Retired Cat Mechanic

Bear and Moon, Glad you had a good experience with Peterson Cat, Starting reading your post about going down to local parts store for thermostats, hope you understand Cat Dealers whether you like them or not , Cat will have the correct part made for Cat engine that was made by Cat spec's. You have a very high dollar engine with what is called a heui system, going low road on oils and parts will cause many problems ahead. Again glad to hear Peterson Cat came to your call. Dave Atherton Retired Cat Mechanic

Brett, sounds like a stuck thermostat or one partly stuck. Coming off freeway so not under heavy load and sounds like this just happen. Possible belt or idler pulley fails check first than thermostat. Dave

KWcowboy, Making sure the IAP sensor is working correct you troubleshooting by removing the Wire Clip and engine would not start tell you IAP sensor is working. Next sensor that is on lower side of HEUI Pump is what we call Injection actuation pressure control regulator. ( what this does is regulate HIGHPressure oil flow to actuate the injjectors and also can get sludged up. ) this is the only operation of the Heui Pump is high pressure oil to injectors. there is also a little diesel fuel transfer pump connected to the heui pump but is not with heui pump. Going with things that you can do, I would sugest and remove the IAPCR valve ( remove wire clip than remove solenoid, this gives room for a 1 1/8 wrench to remove the solenoid.) You can check the solenoid for ohms and if reading is at 10 solenoid is good. than take and shake the regulator body back and forth should hear a clicking noise of little plunger sliding back and forth. if you cannot hear any noise after trying several times than the shifter plunger is stuck or sticky while running. This is a $ 275.00 part , and the IAP sensor is $ 185.00 aprox so this is why having you troubleshoot will remove someone else putting on parts on your nickel. going back to the regulator, cannot hear any noise inside while shaking. You can take apart valve, hold hex end in vice and channel lock pliers turn off barrel that screws into body. put a clean grease rag under this barret a very sall needle can drop out and get lost. ( that is the only small part to worry about ) than take a flat blade screw driver and turn out slot in housing ( behind that screw in the shift plunger ) will come out last part. look over and can see tracking on one end or other if possible sticking. but in most cases just sludged up. as long as electric solenoid test out for 10 ohms you can uuuse brake and clean plunger housing and all parts removed put back together. again make sure the little needle is in the barrel on last part thet screws into regulator housing. this seems like a lotof work but you have control of the repair not repair shop. there is one more update that may be causing the problem but working away from heui pump is best direction to take and not costing money Dave Atherton Retired Cat Mechanic ( 42 years )

Kwcowboy, with what your saying sounds like the IAP sensor is going down or bad. What has happened Oil Sudge Gets into the sensor and electronics cannot recieve a good signal. You can check the IAP sensor by unplugging the Wire pigtail that feeds the sensor. With IAP sensor unplugged now see if engine will start and run. If engine does Start and runs replace the IAP sensor it is bad Dave Atherton Retired Cat Mechanic

Gentleman and ladys also, think we need to understand what a Class B license is. ( this means if you drive anything over 26,001 pound other than it is a law that you have a class B license with air Brake endorsement.think about it this way retired and buy a big diesel pusher motorhome, It has air brakes, salesman takes you for a test drive and last thing salesman will say to you do not forget to push the yellow button by steering wheel or along drivers window. Cannot tell you the repairs done on motorhome brake system from not understanding what was meant by Air Brake endorsement. Gentleman its all about safety ( i'm not saying us retired motorhome people are bad drivers but what I'm saying there is a ton of information lacking in this area ) I even have people cannot figure what the truck runaway ramp are reallly nessary. Let count our blessing as we get older that we can still drive without, what is called a CDL for all motorhomes over 26,001 pounds. Yes a motorhome is not a car or is a truck, but lets try a bus maybe we can someday be located with a area of our own. In the mean time, Safety with Air systems and air brakes can be very unforgiving with lack of the understanding of how systems work and what can happen going down steep Mt. grade at Vail, Co. Dave Atherton Retired Cat Mechanic

Thanks Bill, nobody really did ever explained how the posting go. Assume with orange flag along posting one would Think it is a current post. Where are the current post located. Thanks Dave

Bill good post, going to fuel pressure sensor on fuel rail ( this sensor is a 5 volt sensor that I mentioned in above post ). and No this group of sensors meaning 5 volt are not meant or designed to be over driven as this would happen with bully dog being applyed.the values of the sensors are clearly spelled out on cummins Insite. as I mentioned the makers of the chips and tuners will present all there plus facts to a certain group and cummins the engine maker will stand with there views. In the end if a person goes out of the box and decides to over drive a electrical sensor with more voltage to provide XYZ power than so be it. The same goes for running above rated rpm's and again yes you can. will damage happen ahead with out of the box additions answer is yes. what is to be gained not following OEM spec's, another point of intrest going with EPA on Diesel exhaust not meeting standards EPA certified the cummins 400 being on top of all the regulations there is a pretty large fine involved in this area. If you read post on the Cat engines and problems meeting present exhaust reg's there is no gray area. Ask Brett, Or Ken Carpenter in last part of July about Cat C-9 re-gen problems and Cat would not bent on EPA rules. I think everyone has there points on the subject but having legal add on with exhaust a person is subject to very large fines for tampering with a EPA certified engine. Dave Atherton Retired Cat Mechanic

Now for the down side of above Bully Dog setup. first of all Ford Navstar diesel engine ( with top end Cat heui system and cat sensors.) With electronic engine engine there are 5 sensors that report direct to the ECM and are controlled 5 volt sensors, and a person cannot over drive voltage to these 5 sensors that are all 5 volt.to increase power, the boost pressure, intake manifold pressure sensor, fuel pressure sensor and last the atmosphere pressure sensor. note that all these pressure sensors are all wired together direct to the ECM. yes you can over drive a 5 volt pressure sensor for a while but need to understand , all the above pressure sensors tied together only thing different is the signal wire from the ECM. when failure starts pressure sensors stop. The cast block engine has a little harden steel insert sleeve that take just so much increased pressure. the engine head bolts will stretch. i have'nt talked about heating up but that is a given. lets go back and remove chip and return to stock to work on engine. one thing all events are recorded on the ECM. where I have been seeing many failures and derate of diesel engines because the above 5 volt pressure sensors are also derate sensors. Cummins has the same 5 volt sensors as above and also will derate engine. we have many pickup pulling big fifth wheel trailers that been along the road and had no power and over heating. most repair shops Ford, Dodge ,Durmax will not work on pickups that havew chipped. this is the same order for Cat dealer and Cummins Dealers. most Deisel engines will go the long mile but when we as owners go away and not listen to the people that build these engines and do not recommend add on chips and tunners, they very much know what there talking about. If there was a dollar to be made with install of chip and tunners than Ford, Dodge,Durmax, big boys with Cat and Cummins. It is spelled out as not worth the risk to a high dollar engine. Dave Atherton Retired Cat Mechanic

Carl good point the cost is not worth with what you will gain. if anything is done to increase power and take it to cummins or cat and put the monkey on someone else. many people talk fuel milage and many talk more power. remember the good old days when you drove a 230 hp cummins than powered up to a 250 and pulled 73,250 truck and trailer together. now we have a motorhome around 35,000# and now have a ISL 400 and want more power driving most of the same roads.Being on a fixed income when is there enough power anymore. Dave Atherton Retired Cat Mechanic

Kent, you have expressed interest in add on chip or tuner to cummins 400 hp engine. Before you think about installing anything thing, this add on is going to come with big price. Do your home work, direct from cummins or if it is cat do the same.find out which sensors will be affected. I all ready know what cummins or cat is going to tell you and I also know which sensors that will be affected. I would suggest on getting real good understanding with how the electronic engine works. I can show without question,why cummins and cat will not respond in favor of chips or tuners. Now the people that make these chips and tuners are going to relate a complete different story, just remember one thing replacement cost for a cummins 400 h.p. Engine. $ 50,000 plus. Reason I'm not going deeper at present about damage that will occur within the engine. Dave Atherton Retired Cat Mechanic

Charlesholman turbo failure, you said Engine was a 425 Cat but not model, I can bet we are talkin about a Cat C-9 with exhaust setup with re-gen. You are having problems with re-gen to work in the auto mode and now will not regen in manual mode either. At Cat dealer you were told that turbo needs to be changed out because oil on face of intake of the DPF filter.At 19,000 miles would suspect this is where the story is going. If this is correct, I can assist you in direction to take. Brett will agree durning Diesel Club pre rally at Madison. Ken carpenter, Brett and myself all involved in assisting on this problem that involved 5 Cat dealers.looking at Cat-9 engine that failed to re-gen. Between the three of us there was a happy ending and party returned back to Ohio with no additional problems. The more information a person can provide would be very useful In assisting you. Dave Atherton Retired Cat mechanic

Good morning had my first cup of coffee and reading the early edition of the FMCA Forum. Great news hearing very Good feed back about the ISC engine with the CAP' fuel system. Keep these good post coming. One thing about many of us older retired mechanic's, we keep out thoughts to ourself about different engines and do not really want to get Into the mix of who has a better engine. I have heard many stories over the years about throw away Engines, Cat Heui Systems, VGT turbo's on electronic cummins, Special extra setting of valves and on, an on. You can read 6 post for bad engines than read 8 post telling how good engine is. Point is this we all have different money put away for the day of retirement and just maybe motorhome is selling that fits out budget. Many of us are, do it your self kind of people. But the bottom line we all love the R.V. lifestyle traveling country in a motorhome. We run into problems and resort to forums for assist with problem. The great part, people from all over the country chime in and provide advise regardless of what there background is, they just want to help his fellow R.V.er. Remember old saying from my father regarding repairs ( it was built by man and can be fixed by man ). Let's keep a positive out look is and sugar coat the downside. Dave Atherton Retired Cat Mechanic

Huffypuff, cannot agree with you more about valve adjustments, Cat has set a standard back in the 80's and is there standard used today with there electronic engines. Settings as follows intake .015 + - .003, exhaust .025 + - .003 what does this mean. Cat position is clear if feeler gauge falls within the above clearance adjustments not needed. Dave Atherton Retired Cat Mechanic

Great reply, question : Where is there a fuel truck stop or service station that does not handle BIO Fuel. Answer BIO Fuel is everywhere and now ratio is posted at 15 to 20 %. Sounds like Diesel owners back In the 60's and 70's from cold states used to blend number 1 fuel with number 2 fuel to prevent damage to injection pump and injectors. I can just about figure what is going to happen, just like add on's DEF now we are going to have to buy XYZ gallon of very special oil at $ 25.00 gal to increase the cost per Fill up. The drill is all about money. Dave Atherton Retired Cat mechanic

ISC Engines, Cummins had a good idea but system has been a problem child. Mainly with the CAP's fuel system, motorhome sitting idle. check valves poppet in the accumulator etc. I had several people say they have around 100,000 miles and like there motorhome. I do not want to down grade engines being a retired mechanic because we have many members of this forum that have the cummins ISC engines. Our goal with this forum is to help respond to a member needs the best we possibly can. We all have our different thoughts on various subjects and I do respect that, but down grade something which another member has, I personally think we should not do. ( this is my thoughts only). Dave Atherton Retired Cat mechanic

WILDEBILL is correct, being a mechanic for so many years a person gets caught up in solving problem deeper than what is happening. Looking some info on a cumms Insite computer readout Diagonostic. just happen to run across something of interest called Duty Cyle Monitor. In addition to diagonostic codes off engine cummins has a chart that tell Driver where the engine rpm's high point and puts all info. on a chart. where I'm going on this on a ISL 400 the peak horse power and torque will show percent of time at what rpm range and will tell Driver how he falls into correct Driving window. example the chart will show advertised power rpm 2800, advertised power at rpm, peck torque rpm, peck torque at rpm. Note this is for a another engine that I had my cummins computer on. To finish with my thoughts on this chart for the engine to have Max.power, the correct peck torque is 1600 rpms and that would give driver 660 ft.lbs. of torque, on A ISL 400 peck torque at 1200 rpm will be 1600 ft.lbs of torque. Again have to agree with WILDEBILL do not think there is a problem, Again try to let motorhome just lug down going midway into steep grade and you will see where the peck power will stay. Most of us have a trend to keep downshifting to keep the rpm's higher around 1800 to 2000. Just go and have fun. If you are around the Quartzsite area in the winter time I can put my cummins Insite computer on your engine and will print out the above information above because it is on the ECM history. Putting all the thoughts on this forum, gives a person a real good over view from many different directions to lean to. In most cases problems are minor in nature. I hope this will give you a better Idea on how a Diesel engine gets peck power is on the reverse side or down side of the engine rpm's Dave Atherton Retired Cat Mechanic f

rwitt, looking over the information I posted above gives a good over view of what sounds like your problem.I would make a suggestion if and when you have your motorhome looked at. your turbo problem is either caused by carbon buildup in actuator housing. bad actuator motor. in many cases bad connection to motor. What cummins is going to tell you that problems found in the actuator assembly. If this the case cummins has stopped selling the small parts to repair actuator motor or little nylon gears inside on actuator housing. they will tell you that the complete turbo has to be replaced and it is very costly. Again I would suggest getting cummins insite readout with print out of problem first. Once you can get copy of ECM readout fault codes, if you would I can assist you once you have Fault codes in hand. I do have cummins insite where I can look up fault code (.this varaible pitch turbo has caused problems ) but before you give a Ok for repair work there is a plan B and will tell you why once we get fault codes. Dave Atherton Retired Cat Mechanic

Gentleman, I do not want to be a nay sayer but lets put the cart after the horse. the subject is about loose hose and talgutbir said it the way it is. put the hose on and run it. The question about turbo being bought into this mix is not correct and will not affect turbo charger in any way. ISL Cummins has what is called a variable pitch turbo, which means a set amount of exhaust will go back into the intake of engine via is a sliding ring and a defuser plate that has a electric motor actuator. the boost pressure in the intake tells ECM more boost than the electric actuator moves the into the defuser.this one area that will give problems because of carbon buildup and will make actuator ring sticky. The ISL also has a cleaning mode at startup for the variable pitch turbo that makes a loud clicking noise while going cleaning mode. Dave Atherton Retired Cat Mechanic