The Forestry Forum

General Forestry => Forestry and Logging => Topic started by: Lockwood on October 16, 2021, 02:05:36 AM

Title: 648h no start
Post by: Lockwood on October 16, 2021, 02:05:36 AM
Hi all ,hoping for some help my 648h was running fine stopped for lunch winds over no start replaced filters cam and crank sensors It started idled fine revved up then I switched it off tried to restart no luck ,Fuel  pressure  sensor up on screen but not sure if that would fix any thoughts ,been trying for 3 days thanks.
Title: Re: 648h no start
Post by: teakwood on October 16, 2021, 08:07:26 AM
@kiko (https://forestryforum.com/board/index.php?action=profile;u=15160) is our mechanical wizard  
Title: Re: 648h no start
Post by: Lockwood on October 16, 2021, 03:54:42 PM
Yes teakwood ,kiko has helped me in the past ,thinking could also be pressure  relief valve but don't know  really 
Title: Re: 648h no start
Post by: kiko on October 16, 2021, 07:25:53 PM
Is the electric fuel pump on the filter housing running and what is the actual  fault code number.  The fuel filter that is up toward the engine fan has a 90° fitting on the back side that constantly clogs with debris.  If supply side fuel  is good , the most common no start low rail pressure comes from the rail relief , injector or hpfp  . You can disconnect the tee where the return lines from each component come together.  On a no start condition basically no fuel should be leaking as started turns.  Even droplets leaking from the rail relief will cause a no start.  
Title: Re: 648h no start
Post by: Lockwood on October 16, 2021, 07:40:51 PM
G,day kiko ,mine has manual lift pump replaced front filter hosing ,do have fuel coming out of rail at lines and pretty sure had fuel coming out of the T lines at return  codes were 1347.05   636.08 157.17 
Title: Re: 648h no start
Post by: kiko on October 16, 2021, 10:36:40 PM
That is definitely an odd combination of codes.  1347 05  open circuit or short to fuel pump control solenoid.  This solenoid is located on the hpfp .  This code can be set if the pump control solenoid is unplugged when key on.  636 08 cam and crank sensor  out if sync.  This could occur if the sensors are unplugged at key on or harness issue. Also if the hpfp is not timed correctly.  157 17 fuel rail pressure minimum is not reached at start.   Find the return junction.  There will be one line that comes from the top ( rocker cover) this is the injector return line. There should be NO fuel returning from this line when starter is engaged.  If there is you have a bad injector or a loose injector tube. Blocking off  each line to the injectors one at a time until the return flow stops at start will isolate which injector or tube is leaking.  As mentioned above,  also at start NO fuel should be returning from the rail relief none.  
Title: Re: 648h no start
Post by: Lockwood on October 23, 2021, 05:48:31 PM
 No start issue fixed .Replaced suction control valve and rail relief. 
Title: Re: 648h no start
Post by: kiko on October 23, 2021, 06:36:32 PM
Sweet!! From here on out the diagnostics for low rail pressure 157, 1347 in a common rail fuel system are the same regardless of engine manufacturer.