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+--- Thread: No start cm 870 (/showthread.php?tid=9027)
No start cm 870 - Ron1 - 07-30-2023
Left grand junction Co. For a job 1 week ago. Ran I 70 to Ohio completed job. Dropped off rental excavator, loaded pickup on trailer pushed in clutch started moving and truck just quit.
Truck is demandated. Good tune from running rough. Truck has run amazing for 3 months with no problems what so ever.
It’s a 2006 Pete with 1.4 million in frame suppose to be 200,000 miles ago.
Truck uses little to no oil.
I did have to replace the high pressure pump a few months ago. As it quit about like this coming down a mountain in colorado. Like someone shut the key off.
I have my laptop with me and yesterday after it quit was able to hook up to the ecm. It was dark and my kid was driving me crazy and I was very tired so I just quit.
Came back this morning and insite will not connect to ecm.
1. Some things I noticed. Oil pressure does not come up when cranking.
2. I did replace fuel filters
3. Lift pump is working cycles for 2 mins I have let it cycle 4/5 times.
4. Insite not hooking up today. So I can’t check the cranking pressure from high pressure pump.
5. I have 12.3 volts at computer plug
6. Truck hasn’t been in rain till this happened in Ohio (lol)
7. I don’t have a way to test fuel pressure. Sunday and nothing is open
I did push compu check port fitting and fuel sprayed out on back on pump.
8. Yesterday after it quit I spoke with running rough and was able to hook up to ecm.
It had 3 codes
A lost power to ecm
B. Fuel filter blockage maybe
C. Fuel actuator #2 I believe.
And I thought a turbo one.
I’m leaning towards bad computer but can’t rule out bad high pressure pump as I have no way to diagnose/tell what it’s putting out.
I wouldn’t be so upset other than I’m 1700 miles from home lol on a Sunday.
Thoughts
RE: No start cm 870 - Nostalgic - 07-30-2023
Not sure the similarities between the 870 and 871 on failures, but when my 871 ECM went, there was no warning, and even after cooling off, I was lucky to get it to run for 30 seconds before it died again.
I'd double check your fuses on the power to ECM for corrosion on the blades, and if you have a way check pins at your diag. port to make sure there's not a wiring issue between the cab and ECM, but the symptoms do point to the ECM with having both a lost power code and not being able to communicate. If it was just the fuel pump, you should be able to connect and see PSI >100 while cranking, and should also see oil pressure when cranking.
It's an out there idea, but could a shorted fuel cutoff solenoid cause these issues, or is there a fuse between it and the ECM?
RE: No start cm 870 - Ron1 - 07-30-2023
I have power at the shutoff. I gutted it anyway to elimate it. Nothing
I did give it a sniff of either and it ran for a second and then died.
I double checked fuses and they are good also checked power connector at computer and it has 12.3 v matching if battery.
So weird how when they shutoff they just die. No burp no buck just stop running.
RE: No start cm 870 - Rawze - 07-31-2023
(07-30-2023 )Ron1 Wrote: I have power at the shutoff. I gutted it anyway to elimate it. Nothing
I did give it a sniff of either and it ran for a second and then died.
I double checked fuses and they are good also checked power connector at computer and it has 12.3 v matching if battery.
So weird how when they shutoff they just die. No burp no buck just stop running.
I hope you disconnected the wire from ecm going to the shutoff solenoid before applying power to the coil. If you put external power to the solenoid coil and it is still wired to the ecm, it will burn out the circuit inside the ecm that activates the solenoid. Seen people do that before.
You need to get Insite software connected to it and look at the fuel pressure while cranking if possible. make sure its well above 50+ psi or the cylinders will not even try to fire off.
Also you mentioned that there is zero oil pressure while cranking. It takes a good 15-20+ seconds to register,... and only registers a few psi, but the gauge should show something. If not then it is most likely a dying ecm. May also be why you cannot communicate with it properly too.
RE: No start cm 870 - Ron1 - 08-02-2023
We just checked for with a voltmeter on the shutoff solinoid, thank god! I have read and read on the forums about putting an external power source. (No no).
Just so everyone knows we got the truck running. Before throwing money at parts, somehow after trailing the truck to a friends. We were able to get insite hooked up, as it was not connecting where we broke down. We had good pressure at the high pressure pump. So it wasn’t that.
Had a funny code electrical At fueling solinoid, so we started looking at wires we found a bare wire near the weather pack. We made sure it was not touching and used electrical tape to make sure it wasn’t shorting to ground. Truck fired up!
Our conclusion right or wrong is we don’t get rain in Colorado. Just before the truck quit we got in a pretty bad rain storm. My thought is it shorted due to the water. I guess I’ll never know. Anyway we drove it 1659 miles back to Colorado Monday afternoon made it back wed morning.
Gonna look into a new engine harness it’s got 1.5 million miles on it. So she’s earned that! Personally I think it’s the best motor I’ve ever owned after demandating.
Thanks for the help. It’s good to be home!
RE: No start cm 870 - Rawze - 08-03-2023
Bang on the ecm while its idling with something and ensure it does not cut out. Another common issue when the ecm starts going bad.
ref: http://rawze.com/forums/showthread.php?tid=8900&pid=76607#pid76607