Author Topic: Revisiting hard starting Cold And Flash codes  (Read 175 times)

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Offline willsonrick

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Revisiting hard starting Cold And Flash codes
« on: October 29, 2019, 11:19:13 AM »
Dave ,
  I have a 3126B, Serial 7AS15350.

I know we covered most of this last spring but I have gone thru every item that I can think of to get to finding an air leak. I wrapped all the connections in yellow teflon tape on the suction side of the fuel pump and the fuel pressure regulator.  Have not redone the high pressre side

I still get a stream of whitish foamy looking fuel out during the  test at the fuel regulator.  It clears up,  but the fuel looks cloudy or foggy for the remainder of the test.  I set the sample aside overnight and the only thing that settled out was some white globs of stuff that settled to the bottom of the jar. The rest still looks cloudy.

Once started the first time in the day,the thing starts like normal. 

Along with this I am getting Flash codes 15,39,51.  I disconnected  the IAP sensor and it started.  I know that means the sensor is bad, but I just replaced it last March.  I cleaned up the battery, IAP sensor, and ECM connections with contact cleaner and reassembled.  I also took apart the injector harness connector and cleaned that. 

Started this AM with difficulty.  Same stream of foamy stuff, cloudy fuel AND same codes 15,39,51 plus  74(injector 4) 
Check engine light flashes every 5 sec while running.  It has not done that before.  Even with the earlier codes.

Took it for a very short drive,  runs rough under acceleration but seems good when off the pedal.  Made it home again same codes.

I may have messed up the reconnect on the injector harness, but I am concerned about the persistent codes and the air leak.

I may have more than 1 problem going and am at a loss.  Any help would be appreciated.  Attached is a couple pic of the fuel coming from fuel pressure regulator.Or just tell me to to Cat Dealer.

Thanks

Rick Willson





Rick Willson, 1998 Safari Sahara Model 3006, 3126 300 hp

Offline ziggyh

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Re: Revisiting hard starting Cold And Flash codes
« Reply #1 on: October 29, 2019, 07:35:55 PM »
Well the fuel sample sure doesn't look like clean diesel fuel.
If I was trying to rule out a suction side leak from the inlet of the pump I would try running the engine from a fuel supply can and hose straight to the inlet to see if that clears up the airated fuel.
ZiggyH

2007 Revolution LE
C9

Offline willsonrick

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Re: Revisiting hard starting Cold And Flash codes
« Reply #2 on: October 30, 2019, 07:12:47 AM »
The fuel coming from the bottom of the primary fuel filter looks clean and clear.  when the see tru bowl is drained the fuel also looks good.

Thanks for the idea.

Rick
Rick Willson, 1998 Safari Sahara Model 3006, 3126 300 hp

Offline David.e.atherton

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Re: Revisiting hard starting Cold And Flash codes
« Reply #3 on: October 30, 2019, 09:30:47 AM »
Rick, yes without question problem with fuel quality and entry of air into fuel system. Few
Questions, first install clear line at the return fuel pressure regulator location at rear of engine head ( note you will see a elbow with a hex fitting about 3 inches long with a fuel hose attached
and facing toward passenger side ). Remove hose and install clear plastic line over male end
and run plastic tube into a container. Start engine up and run there should not be any air
bubbles in the fuel except a little trail of pin size bubbles. Next speed engine up and hold steady
Rpms at 1/2 for two minutes again no air bubbles , than same at 3/4 rpms same thing. This
Test will tell us and lead you to your problem. Do this test let me know your findings .
Ask Dave, Dave Atherton Retired Cat Mechanic

Offline willsonrick

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Re: Revisiting hard starting Cold And Flash codes
« Reply #4 on: October 30, 2019, 09:56:37 AM »
Dave,

The photos I attached are the results of doing that test.  While doing the test the first 6-10 inches of the flow had the white foam and then quickly turned to the cloudy fuel.  Didn't see air after though.  Ran engine for 3-4 minutes and the cloudyness did not clear up. Thanks.   The coach started well after that. Started but did not runs so good when on throttle. All the flash codes are still the same, 15, 39,51 and 74.   

I do have a separate question about flash codes.  They only display when running, does that mean they are active at that point in time or could they be from earlier?

Thanks
Rick
Rick Willson, 1998 Safari Sahara Model 3006, 3126 300 hp

Offline David.e.atherton

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Re: Revisiting hard starting Cold And Flash codes
« Reply #5 on: October 30, 2019, 11:36:00 AM »
Rick, breakout of the following flash codes, number 15 Injection Actuation Pressure Sensor
Circuit Fault,  low power Derate engine speed, service engine,  number 39 Injection Actuation
Pressure System Fault, low power, engine shut down, engine service,  number 51 intermittent
Battery power to ECM,  engine misfire, low power, engine shut down , engine service, number
74 cylinder 5 Fault or cylinder 6 Fault,  engine misfire , low power, engine service. What I’m
seeing breaking out flash codes is over due engine service. Note with Heui Injection systems
engine oil will sludge and sticky injectors and other engine components. Last would suggest
Taking engine oil samples at engine service times. Ask Dave, Dave Atherton Retired Cat
Mechanic

Offline willsonrick

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Re: Revisiting hard starting Cold And Flash codes
« Reply #6 on: October 31, 2019, 06:20:54 AM »
Dave
We only have about 3000 miles on this oil and the fuel filters have less than 500 miles.  I have been fighting this since before the last oil change after the engine overheated.    Once started and running the engine runs good and starts good the rest of the day.  I did not have the 74 code until I cleaned the connectors.  I am due to change the oil anyway.  I don't see the connection  between the oil and fuel side causing cloudy fuel and air in the system.   Even after sitting in container for 3 days the cloudiness is still there and the white stuff has turned brown and stays at the bottom..  Would a Cat dealer be able to analyze the fuel?  Thanks again.


Rick Willson, 1998 Safari Sahara Model 3006, 3126 300 hp

Offline David.e.atherton

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Re: Revisiting hard starting Cold And Flash codes
« Reply #7 on: October 31, 2019, 07:37:57 AM »
wilsonrick, we need to understand I’m not challenging you on your service operations, however
I did take the effort to look in to the flash codes on Caterpillar SIS technical information and
I did not make any personal views other than relating factual information forward . You can believe and address problem whatever you feel you thoughts take you. Taking oil sample at
service due times would have answered technical information Dave had posted for you from
again factual source. Ask Dave, Dave Atherton Retired Cat Mechanic

Offline willsonrick

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Re: Revisiting hard starting Cold And Flash codes
« Reply #8 on: October 31, 2019, 01:04:43 PM »
Dave, 

I was not challenged or offended. I know you know more than I will ever know about these engines.  I was mostly curious as to how that recommendation came about.  I was also attempting to update you on the current service record, since I failed to pass that info to you earlier..   I am due to change the oil and have no reservations about following your recommendations.  I haven't in the past taken oil samples but I can certainly start.

I am a little concerned about the cloudy fuel and the residue.  To go way back to last summer, these problems did not happen until after we overheated and derated on the highway coming home from the Safari Reunion.   

My thoughts to proceed with the service as you recommend and  reconnect the Injector harness and ECM connectors to see if I bent a pin or something.   If this doesn't clear up the symptoms,  may I reconnect with you as to further steps.?  I do appreciate the effort you put in to help me  and I do and will not worry about you chewing me out.  Thanks

Rick Willson
Rick Willson, 1998 Safari Sahara Model 3006, 3126 300 hp

Offline ziggyh

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Re: Revisiting hard starting Cold And Flash codes
« Reply #9 on: November 10, 2019, 04:19:58 PM »
Clean Fuel
ZiggyH

2007 Revolution LE
C9