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cumminsdr, Mechanic
Category: Medium and Heavy Trucks
Satisfied Customers: 3642
Experience:  All types of Cummins applications
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Cummins l10 wont shut off, 1987 peterbuilt cummins l10, Just

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Cummins l10 wont shut off
JA: What's the make/model/year of your truck? Engine type?
Customer: 1987 peterbuilt cummins l10
JA: Are you fixing your truck yourself? What have you tried so far?
Customer: Just rebuilt engine out of two engines head was supposed to be pretty new injectors not sure guessing they are newer aswell. I tried cleaning the fuel shut off solenoid rechecked fuel injector setup
JA: Anything else you want the truck mechanic to know before I connect you?
Customer: It runs rough for around 30 seconds before it shuts down idle has a slight lope to it

Were the engines of the same CPL number? Some parts do not interchange. WHat were the engine serial numbers of both engines. ?

Customer: replied 9 months ago.
Cpl 835 cpl1346

Ok what is the Serial number of the one you put together to run? The engine that has the issue???

Customer: replied 9 months ago.
Customer: replied 9 months ago.
The cams and cranks are exactly the same

Do you have both serial numbers handy? Cranks and cams do not matter..

Pistons, turbos, heads injectors matter

Customer: replied 9 months ago.
The serial numbers I have only one... the # is missing off of the other
Customer: replied 9 months ago.
Customer: replied 9 months ago.
I ordered all the parts to this serial # since the other is missing
Customer: replied 9 months ago.
I put in all new parts pistons cam the crank I used from the other engine and the head and turbo these engines have been sitting for a few years aswell

Ok let me check

So you have a mishmosh of parts in this engine

CPL 835 -------------------------- CPL 1346

CAM--(###) ###-####-----------------CAM -3820013


CYLINDER KIT (Includes liners---3800801) PISTON Wrong for CPL 1346--- Piston(###) ###-####is correct and liner is the same for both engines

INJECTOR-3045102PX-------------Injector(###) ###-####x


Customer: replied 9 months ago.
I did notice a slight difference in the bowl of the pistons but it was so minor. Plus the head that I used matched the pistons that I ordered.
Customer: replied 9 months ago.
Wait no the head was on it i just changed the head and crank.
Customer: replied 9 months ago.
Cam I meant
Customer: replied 9 months ago.
The boss wanted to do it this way.... now it's a real pain
Customer: replied 9 months ago.
When it starts it starts and runs good sounds nice. When you turn it off it lugs for like 10 to 30 seconds
Customer: replied 9 months ago.
Heard it could be a check ball in a injector

Wel The CPL is in place for a reason This is what the engine needs to perform to the fullest If there are changes to the hard parts than you will get a dud. well you have to pick a CPL and stick with it. The original esn should be stamped pn the block to the rear of the fuel pump side under the head . it may be hard to see clean it up with sand paper. Your injectors don't have check balls... . That came out with the ISX engine. gezz.

Customer: replied 9 months ago.

More like mismatched injectors to pistons and heads . even a cam with the wrong timing will cause your issue. Did the old engine have an offset key in the cam to advance or retard timing.., these are the things to concider..

Customer: replied 9 months ago.
I have both of the old cams here still how can I tell?

The part number on the end of the cam towards the back . and the wold-ruff key should have a part number on it or grooved to the left or tight if offset

Customer: replied 9 months ago.
The cams do have different part # ��I pulled the cam gear off of part #(###) ###-####
is an offset key for that cam

You cannot just put an Cummins engine with different parts they will not work together and cause severe engine damage. Use the ESN for CPL and ESN for the engine you want to build for correct parts .. Not the other..

Customer: replied 9 months ago.
Cool I will check some stuff out and get back to you.

ok just reply back to this post . O will be here

Customer: replied 9 months ago.
I forced the injectors down one at a time while it was lugging nothing happened on one and two # 3 shut the engine down instantly I tried this like 6 times. Worked everytime I think #3 is bad what would cause this??
Customer: replied 9 months ago.
Have you seen an injector do this it seems that when you take power from the fuel shut off solenoid should just shut it down that injector must be open all the time I guess

You have STC injectors forcing them down will cause them to fail. the tolerance is in the adjustment The injectors are mechanical and not supported by the fuel shut off solenoid. The solenoid has NOTHING TO DO WITH THE INJECTOR. The fuel shut off sel allows fuel from the pump to injector/ Are you a mechanic? If not have the unit taken to a Cummins shop..

The fuel shut off solenoid takes the fuel away from all injectors and shuts the engine down...AKA the FUEL SHUT OFF SOLENOID....,I think this is above your skills and need to take to a Cummins for repair

Customer: replied 9 months ago.
you are correct I am a mechanic but I only work on cat cummins is a lot different I am doing what I am told doing the best with what I have been given so bare with me. This engine does not have stc valve.
Customer: replied 9 months ago.
I have no books this engine has been very difficult to find info on.

The injectors you installed are STC, All older engines are STC.

Step Timing Controlled. = STC

The service books are not printed any more. You are in the dark. unless you have a Cummins look at it. Before you get into a issue . I can only help so far without being there , But i see a of problems already

Customer: replied 9 months ago.
I read about the stc valve so called a shop they said the stc valve could be sticking or need adjusting but there is no valve like the describe on this engine. I am new to these is whole setup. Like I said I did what I was told just trying to make it as right as possible. They are the same shop that recommended I do the cutout test on the injectors.
Customer: replied 9 months ago.
I know I am lost on this one. Thank you for your patients with me. I have been fighting with this truck for two days now. The cut out test they recommended did seem to work even though you say I could damage the injectors. Cause when I pushed the plunger into the injector only on #3 it kills the engine instantly I tried turning the key off and tried the same test on all the others it did nothing. Just lugged no change #3 instant shut down.

your trying to put two different engine r types together. it WILL NOT HAPPEN. Pick the CPL and ESN and rebuild it to that spec..... With the correct parts for that ESN/CPL

Try swapping injectors from #3 to like #5 and see if it follows. If so replace the injector. Then see what happens.

Customer: replied 9 months ago.
Cool thanks I will try it

ok . Pleas e don't forget to rate my service.

Hi just following up. Please don't forget to rate my service.

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