DaveAtherton

Radiografter, reply to ISC cummins 330 engine. What you have going on fuel injection pump problem on your CAP'S fuel system. Engine ECM has detected an overpumping malfunction in the cummins accumulator pump system ( CAP'S ) pump. Effect: Lowpower, possible engine shut down Fault Code 329. Here is the fix, the above will generate fault code 539 Transient suppressor circuit which detected open circuit to the injection valve in engine harness. Part number for transient surge suppressor cummins part 3944110 cost $ 105.70 All this part is a big resistor for the CAP'S system. location follow wire about 12 inches off back of Cap's pump will see resister in metal clip with plastic zip tie Dave Atherton Retired Cat Mechanic

rwitt, I can pull information up on my Cummins Insite about low power ( will need model number ) ISL 400 What? the Cummins ISL has a variable pitch turbo that returns a set amount of turbo gas into the intake of the engine. I did see response with fuel filter dirty problem, than the turbo boost. the turbo boost is where problem located. How the variable pitch turbo will work it has a sliding ring and a defusuer plate which controls turbo boost pressure. this ring will move back and forth via of a electric actuator. this ring and latch operation gets carbon build up and sticky movement. there is a warm up mode which cleans the carbon from this ring and latch assembly. sounds like a clicking sound. this is a common problem with the variable pitch turbo setup. If cummins connects there Insite computer into your system you will find inactive codes like fault code 2388 VGT Actuator Position Failed, Automatic Calibration- Out of Calibration. in many times the code is inactive. fault code 2387 VGT Actuator Driver Circuit ( motor)- Mechanical system not responding or out of adjustment. Some as simple as a wire connection to motor. last going with possible wire connection dirty or loose or grounded. Fault code 2383 VGT Actuator Driver Circuit -Current below normal or open Circuit. Again note: this controls your turbo boost on the ISL. Having a complete engine model and s/n would be very helpful in helping you. Cummins ISL 400 HP. is a real good engine and a very high mile engine, but this one area that will cause problems. Dave Atherrton Retired Cat Mechanic

Mike, Maybe I can answer your question on turbo boost..first of all understanding just how turbo boost works. The turbo charger has a wastegate and a wastegate actuator. Your engine has Max boost pressure at idle with waste gate in the closed position. When engine speeds up the wastegate will start to open (note: the air / fuel and boost pressure sensor control opening of the waste gate) The wastegate has a preload spring set for each different H.P. engines. For the ISC engine opening for wastegate is 23 psi. What happens is as you build up boost pressure the wastegate on engine will open and dump excess exhaust out the exhaust pipe. By a preset value set on the wastegate and opening of wastegate at said value this controls the speed of engine. Note: as explaining above increasing the wastegate setting above engine spec's a person will not increase power but lose power because wastegate is opening wider and dumping more exhaust from turbine on the exhaust outlet. Adjustments made to the actuator arm to keep more pressure on wastegate from opening above engine spec's again will only cause damage to your engine. Dave Atherton Retired Cat Mechanic

Yes, we will be working with the Beaver Group doing security. Dave

Newmar 2000, been thinking your problem is not all low voltage, reason you indicated engine quit in moving off road and restart and going again. New batteries check alt for output voltage. If charging tells engine is getting correct voltage and possible fault gauge or connection. Here is where I'm going , you have a 5 volt sensor going bad, connection to sensor dirty. Would suggest check out your charging system and than drive motorhome. Problem happen again off and on because this is a event code that will reset itself and you will go again. If this happens again get with Brett and we will get you going. If what sensor I'm thinking will take about 15 minutes to install at a Cost of aprox. $ 137.00. Dave Atherton retired Cat Mechanic

Yes Electronic Cat engines need correct voltage without question. There are sensors and regulator that will either Derate engine or ECM will shut down engine. Just signed in today. Dave Atherton Retired Cat Mechanic