951 code cylinders power imbalance cummins isx cm570

[mondao]

I have a problem a cummins isx 450 in truck,Idle the engine failure has fault code 951 inactive 12 counts
I cleaned the entire fuel system and fuel pressure is 275psi, the cylinder performance test all cylinders are working well maybe, I find two nozzles with low performance, my question is which of these I have to change? turbocharger with 18 psi at full load
engine sounds like its working extremely hard, but it isn't doing the job. This truck has no torque on hills,someone will have an idea works with a weight of 35 tonnes on the back
sorry for my English

[colh]

i've got a cummins isx 500 in truck,Idle the engine failure has fault code 951 inactive 12 counts
I cleaned the entire fuel system and fuel pressure is 275psi, the cylinder performance test all cylinders are working well maybe, I find two nozzles with low performance, my question is which of these I have to change?
sorry for my English
I have not used 7.4 yet but in 7.3 when you did power balance test in diagnostics it showed cylinder number that was contributing least are you getting that or are you just reading fault saying 2 cyl,s low on performance?

[servando]

tuve un caso similar y fueron las actuadoras....inclusive si cambias inyectores de posicion...el desempe?o sera el mismo en ambos.....checa tus valvulas actuadoras...dale un servico menor

[mondao]

tuve un caso similar y fueron las actuadoras....inclusive si cambias inyectores de posicion...el desempe?o sera el mismo en ambos.....checa tus valvulas actuadoras...dale un servico menor

and change of position actuators and there is no change in the performance of the cylinder, some other idea

[mondao]

I have not used 7.4 yet but in 7.3 when you did power balance test in diagnostics it showed cylinder number that was contributing least are you getting that or are you just reading fault saying 2 cyl,s low on performance?
I use 7.3 7.2, and the same test result, cold or hot the engine is always the same graph in the performance test at idle
2 low cylinders, and two very high

[colh]

I use 7.3 7.2, and the same test result, cold or hot the engine is always the same graph in the performance test at idle
2 low cylinders, and two very high
I think you would have already checked but are you sure ECU voltage is good,have seen three engines 1 isx and 2 series 60 low voltage ,strange codes and sound like they are running out of fuel,they start cutting back on some cylinders just like a mechanical engine with low fuel.ISX had one good battery it was the one I checked at start but the other battery had the wires for the ECU.I should have checked it.It had Cummins mechanics fooled too for 4 days.! new battery fixed it.

[mondao]

I think you would have already checked but are you sure ECU voltage is good,have seen three engines 1 isx and 2 series 60 low voltage ,strange codes and sound like they are running out of fuel,they start cutting back on some cylinders just like a mechanical engine with low fuel.ISX had one good battery it was the one I checked at start but the other battery had the wires for the ECU.I should have checked it.It had Cummins mechanics fooled too for 4 days.! new battery fixed it.
ok mate, will try tomorrow with another truck IFSM
and also with an ecm and a new battery and I will test the whole electrical system and see what happens thaks

[colh]

It may not be the prob but after the issues had with truck engines and even car ECU,s I go to voltage first just to be sure because they can start up OK but not run right with low volts.Hope I have helped and not hindered let me know.Regards

[mondao]

I've had no luck, try a IFSM of another truck, also with an ecm, but I can not remove the fault:banghead:

[colh]

I've had no luck, try a IFSM of another truck, also with an ecm, but I can not remove the fault:banghead:
On power balance test in diagnostic tests are same 2 cyls always low and other 2 always high or do they swap around with all cylinders and are 2 poor cyls next to each other always

[mondao]

are always two cylinders 3y4 low engine exhaust does not sound right

[colh]

are always two cylinders 3y4 low engine exhaust does not sound right
Can you disconect fuel solenoid wires and crank engine and detect variation in crank speed

[mondao]

On power balance test in diagnostic tests are same 2 cyls always low and other 2 always high or do they swap around with all cylinders and are 2 poor cyls next to each other always

Tomorrow will try with one another engine injectors, maybe the problem is this

[mondao]

Can you disconect fuel solenoid wires and crank engine and detect variation in crank speed
ok good idea also takes away the exhaust manifold, the first time I have this problem

[colh]

Yeah it could just be mechanical issue and ECU gives out poor diagnostics,let me know how you get on as trougleshoot in insite for 951 code is very poor and only talks about fuel but could be lots of things.The 2 cylinders working hard could be just compensating for2 week ones.

[mondao]

thanks mate, I will comment tomorrow if ay any changes, I hope

[mondao]

I had no luck today, change all the injectors, another engine with good performance, but I fail to remove the fault, are two cylinders with low contribution (3y4) someone has an idea what is going on this engine
please any help is welcome

[RSwire]

How is your compression, you could have a bad head gasket between those two cylinders.

[mondao]

I run the test (Blowby) exhaust gases pass to Carter, the test gives me a good result [6.0 inches. H2O] under full load on the road with trucks loaded.
no problem in high coolant temperature, this is very strange for me

[colh]

I run the test (Blowby) exhaust gases pass to Carter, the test gives me a good result [6.0 inches. H2O] under full load on the road with trucks loaded.
no problem in high coolant temperature, this is very strange for me
Hi again mondao are intake valves and and cam lobes etc good on those two cylinders as in are they opening fully

[mondao]

hi, all good I can not find where the problem, the last option will have to remove the cylinder head

[colh]

hi, all good I can not find where the problem, the last option will have to remove the cylinder head
I think you have ruled out most of the other things by a process of elimination, you will be pleased when you find it.Regards col

[mondao]

:banghead:I think it only remains to remove the cylinder head, you have some idea before removing the cylinder head?

[colh]

:banghead:I think it only remains to remove the cylinder head, you have some idea before removing the cylinder head?
No I think you have covered most of it.Will be interested to hear what you find though engine only needs air fuel and compression at the right time.You have covered air,fuel and compression and fuel timing should have come right with replaced ECM unless crank/cam position sensor is giving wrong signal but you would think it would be all cylinders timing out not just 2 or perhaps 4 including the 2 with high readings. ECM,s believe everything they are told even if it is wrong.All the best regards col

[colh]

Mondao Did you find something yet? Col

[mondao]

now only work part time, I tested with some sensors and wiring of the engine, but achieves nothing, in the afternoon the client had already finished with my good day, I had to use my last option, I spoke with a distributor cummins and I discuss the problem, tomorrow send a technician to help,opss
pleasant greetings

[mondao]

maybe it is a very difficult case

[colh]

The difficult ones sometimes you run out of time and customer needs machine,you were probably close to finding the answer.regards cpl

[mondao]

hi, today received support cummins not worked hard to find the problem, just remove the injectors and they told me here is the problem, one of the seals do not seal the fuel injector, the problem is inside the cylinder head a fuel passage is an interference between fuel return and fuel supply
cummins dealer send a new cylinder head free for the owner of the truck, wait a few days to install the new head
:wink:
(Problem of manufacture of the cylinder head)
I hope you understand my English
wow, very nice

[colh]

hi, today received support cummins not worked hard to find the problem, just remove the injectors and they told me here is the problem, one of the seals do not seal the fuel injector, the problem is inside the cylinder head a fuel passage is an interference between fuel return and fuel supply
cummins dealer send a new cylinder head free for the owner of the truck, wait a few days to install the new head
:wink:
(Problem of manufacture of the cylinder head)
I hope you understand my English
wow, very nice
So was it fuel bypassing the injecters and just returning to tank

[dimitar22]

hi, today received support cummins not worked hard to find the problem, just remove the injectors and they told me here is the problem, one of the seals do not seal the fuel injector, the problem is inside the cylinder head a fuel passage is an interference between fuel return and fuel supply
cummins dealer send a new cylinder head free for the owner of the truck, wait a few days to install the new head
:wink:
(Problem of manufacture of the cylinder head)
I hope you understand my English
wow, very nice


The cummins distributor in my country would never do that even if they send a technician it would cost a lot of money.

[mondao]

The cummins distributor in my country would never do that even if they send a technician it would cost a lot of money.
cummins is here in mex. n.1 has an excellent service
might not be as high cost, a road rescue service 35dollars+- for an hour, there were only a few cases with this problem in the cylinder heads
This is the reason of free service, I will try to put a picture
(I hope not to bring spam)

[superc0]

i learn new things today, hard case mondao.

[mondao]

a very unusual case here in mex.5 failures here in our country

[dimitar22]

Do you have any pictures of the cylinder head to see what the problem was.

[mondao]

I'm sorry but I can not put a picture, not really appreciate the defect in the photo
only is the interior cavity of the cylinder head where the nozzle n.4 stay where orings seal the nozzle against the head

[mondao]

Attach the leak test kit, Part Number 3164231, or equivalent, to one of the three male connectors (metering, timing, or return) on the plate.
Apply 207 kPa [30 psi] of air pressure and shut off the air supply with the ball valve.
The fuel passage must maintain a minimum of 193 kPa [28 psi] for 30 seconds.
If 193 kPa [28 psi] is not maintained for 30 seconds, verify that none of the test hardware is leaking.
The only repair available is the replacement of the o-ring sealed plugs located at the ends of the cylinder head that terminate the fuel rail drilling. If the leaks are from any location other than these plugs, the cylinder head must be replaced.
(you have to use this to give a good service they told me)

[colh]

The cummins distributor in my country would never do that even if they send a technician it would cost a lot of money.

You are right here in Aus they would not even tell you what was wrong,they would just send account .

[mondao]

here in my country if you have a fleet of trucks with these engines you will have a good service

[hanzem evr]

Hi guys please help
I have problem with truck engine type isx400 cm570
the engine work with good condition and no active code found by INSITE but i cant start engine with out adding some gasoline in breather (start aid fluid) So the start motor
changed with new and batters also , this info during starting
175 rpm , fuel pressure 15 psi, battery volt 11.5v, no active code, fuel pump work, no air in fuel, fuel pressure regulator not creaked or damaged o-rings ,

So what the problem with difficult starting ?????

[MELEJ1]

here in my country if you have a fleet of trucks with these engines you will have a good service

Hi Mondao,
Currently I have a problem with this ISX engine, the codes are 378,394,396 and 398, also I have imbalance in the injection system, I'll try another ECM and you'll notice, perhaps you have these codes?
I'm in Mexico and if I can help, send message to 7711832074.
I worked at Cummins Dexel as Regional Service Manager

[MELEJ1]

CHECK THE BATTERY'S AMPS AND CLEAN THE TERMINALS, MAYBE YOU HAVE TO MAKE A TEST WITH ANOTHER BATTERY'S

[mondao]

I work in the Sierra Madre Mountains, not far no internet no phone