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+--- Thread: Cm871 timing? (/showthread.php?tid=9858)
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Cm871 timing? - 09Pete386 - 12-12-2024
Cm871 timing
I lost power and efficiency after installing a new head could it be the timing?
Also boost is around 30 psi and won't hit higher, before was 38-40
But that boost was before I changed the head.
RE: Cm871 timing? - Heavyhauler - 12-12-2024
Im almost positive that the ECM knows if its with in timing.( some one here can confirm) If you were off I would imagine you'll have a fault code almost instantly indicating timing. Did you wedge the cams while timing ?
RE: Cm871 timing? - 09Pete386 - 12-12-2024
(12-12-2024 )Heavyhauler Wrote: Im almost positive that the ECM knows if its with in timing.( some one here can confirm) If you were off I would imagine you'll have a fault code almost instantly indicating timing. Did you wedge the cams while timing ?
Thanks for the reply, yes I did wedge the cams, I followed Rawze YouTube videos of everything, it started right up just not sure what else it could be,
RE: Cm871 timing? - Pigpen 2869 - 12-12-2024
Did you remember the plug that goes in the head that everyone forgets ???? Just ahead of where the intake is facing up.
RE: Cm871 timing? - Heavyhauler - 12-12-2024
Ill assume you've checked turbo clamps, hoses , turbo charge cooler, could be a leak when boost is built with in the system, also giving you bad effiecency all in one shot?
RE: Cm871 timing? - 09Pete386 - 12-12-2024
(12-12-2024 )Heavyhauler Wrote: Ill assume you've checked turbo clamps, hoses , turbo charge cooler, could be a leak when boost is built with in the system, also giving you bad effiecency all in one shot?
No I didn’t forget the pin I took that out right before turning over the engine by hand
RE: Cm871 timing? - 09Pete386 - 12-12-2024
(12-12-2024 )Heavyhauler Wrote: Ill assume you've checked turbo clamps, hoses , turbo charge cooler, could be a leak when boost is built with in the system, also giving you bad effiecency all in one shot?
Yes I’ve checked everything
RE: Cm871 timing? - tree98 - 12-13-2024
(12-12-2024 )Heavyhauler Wrote: Im almost positive that the ECM knows if its with in timing.
Nope the ECM will not know if it's out of time. It's going to assume the timing is correct. Did you time it with the correct wedges and the crankshaft pinned?
Is this a genuine cummins head from a dealer or something aftermarket?
Is this engine demandated? If so are the cans 100% hollowed out? Also does the program in the ECM match the program that's called for on quickserve for your ESN ?
Completely loosen all the rockers and then pressurize the entire engine with shop air by blocking off both sides of the turbo and putting 35 pounds in through the turbo inlet temp sensor port. This will show you were your losing boost if you actually are.
You should also do a bubble test on the injectors
https://youtu.be/Wu_WN8BA-LA?si=fsmA7h-3Z_sg0422
RE: Cm871 timing? - Rawze - 12-13-2024
(12-12-2024 )Pigpen 2869 Wrote: Did you remember the plug that goes in the head that everyone forgets ???? Just ahead of where the intake is facing up.
I would second this one. here is a related thread...
http://rawze.com/forums/showthread.php?tid=9194&pid=78638#pid78638
and yeah... if the engine is de-mandated then also have the program copied from the ecm and e-mailed to me for review so that it can be checked out properly to ensure its safe for the engine and turbo. To make sure that your engine does not get torn up again due to horrible delete programming.