cm870 wont crank hot

[Rawze]

you guys might be waay over thinking it too ...

U know if the fuel bleed-off orifice for the injection timing circuits is going bad in the IFSM, it can cause hard starts until the engine cools off.

it is mentioned starting at 0:58 in this video. It goes on to mention the 0.008" bleed-off orifice that prevents hard starts and excess pressure once the engine is shut down...
https://youtu.be/_WeiDC6S8Lw

Just a thought.

If it is this orifice, or circuit is clogged up in the IFSM, then it would be also highly likely to contribute towards high oil temps too, as the injection timing would get screwed up as well from improper fuel flow quantities to the timing circuits.

Maybe pulling off the entire FISM, dissembling it entirely and cleaning all the valves, check valves, cross channels, components, etc. and that orifice (there is an access plug in the bottom of the IFSM to get to it from what I have gathered, though I have not done it). -- or replacing the entire thing with one off another truck that runs good as a test.

==== Aside from what I have described above being the entire culprit, the next thing to do is ...

Once the hard start issue is resolved ... if high oil temps persist as a separate issue ...

-- as far a the high oil temps, he needs to verify the oil temps are accurate within a few degrees using a temp gun (on the oil filter perhaps if need be like others mentioned). Replace the oil temp sensor if necessary.

Then the next step would be to replace the oil cooler and thermostat. it could be that the thermostat is going bad, I have mentioned that to him when he was here, and it also can be that the oil cooler itself is partially plugged, or anodized internally and unable to do a proper job.

Personally, I would point my finger at the IFSM orifice and its bleed-off circuit. That makes the most sense so far. That bleed-off line is only 0.008" big and VERY easy to get clogged up, especially if the truck has ever had algae issues, or some moron was not changing the fuel filter often enough on it, or was pre-filling the fuel filter with possibly contaminated fuel. Cummins says to always put the fuel filter on dry and clean, let the electric lift pump fill it before starting engine.



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