Cat 963C won't start

mohamed hodroge · Dec 5, 2022

Hi guys,
I have a CAT 963C SN: ABBD02578 with 3026b engine. The fan belt broke with the engine running. We replaced the belt but the engine won't start after that. We tried bleeding and priming with aerosols but still won't start. I feel like I'm missing something. Any help/advice will be most appreciated. Thanks a lot.

fest777 · Dec 5, 2022

try disconnecting the battery for 5 min then try to restart, also did the fan belt hit any electrical connections ?

sawmilleng · Dec 5, 2022

Hoo, Boy, Now I've heard everything!! Heavy equipment is getting quirky like a computer! If it wont start unplug it and then plug it back in!!

Jon.

Simon C · Dec 5, 2022

The belt must of hit a sensor or wiring harness. Did it run a long time with the broken belt. Is it cranking over with sufficient speed. It may have depleted the batteries if the alternator is run on the same belt. Just a few simple things to check. Hope it helps.
Simon C

mohamed hodroge · Dec 6, 2022

fest777 said:
try disconnecting the battery for 5 min then try to restart, also did the fan belt hit any electrical connections ?

Yes, well we disconnected the batteries for recharging (~24h), no start. I checked the electricals, nothing seems out of place. But I'll check again.

mohamed hodroge · Dec 6, 2022

Simon C said:
The belt must of hit a sensor or wiring harness. Did it run a long time with the broken belt. Is it cranking over with sufficient speed. It may have depleted the batteries if the alternator is run on the same belt. Just a few simple things to check. Hope it helps.
Simon C

Thanks Simon C
We tried disconnecting & recharging the batteries, tried bleeding fuel lines, checked heui pump solenoid, electricals seem ok.
The engine swings quite well. We tried priming with aerosol spray into the air intake, and it would attempt to start, but dies again if we discontinue the aerosol. I guess this means no fuel is entering the combustion chambers from the injectors.
The question is Why?

Mobiltech · Dec 6, 2022

Is there a positive air shutoff on this unit? If so make sure it’s not tripped.
This engine has 2 speed timing sensors that go into the backside of the front housing down below the heui pump. Make sure the wires are ok and maybe remove them and wipe off the magnetic tip.

mohamed hodroge · Dec 6, 2022

Mobiltech said:
Is there a positive air shutoff on this unit? If so make sure it’s not tripped.
This engine has 2 speed timing sensors that go into the backside of the front housing down below the heui pump. Make sure the wires are ok and maybe remove them and wipe off the magnetic tip.

Thanks for the advice. I'll check for the air shut-off and speed timing sensors. Hope this works.

Simon C · Dec 6, 2022

Check very carefully as Mobiltech said around those sensors. The fuel tank is full and someone didn't come and siphon it out by chance. Have done 1 call out for this. Also a friend recently had a belt break on a Cummins and it shorted a wire to a cam sensor before it shut off. Is there clean power going to the computer. Just had a truck, where I work most with a loose fuse that feeds computer positive terminal. They were going to change the computer for $5000 and found the loose fuse first.
Check all these simple things first.
Simon C

Simon C · Dec 7, 2022

Does that engine have a fuel solenoid. Maybe a power supply issue to it if it does. Just thinking of simple easy things to check. Does the engine crank over faster if boosted is my question? Maybe there is insufficient fuel pressure for it to start. Just wondering about all you have tried.
Simon C

MyMRO · Dec 7, 2022

You can check the shut off solenoid first, hope it's helpful.
MyMRO

Simon C · Dec 7, 2022

If there is no smoke at all out of exhaust, that would point to fuel solenoid or power to solenoid problem. Maybe you could try running power to the solenoid to bypass control systems. Could hook up a gauge to check fuel pressure. I am not there to help. Hope you figure it out.
Simon C

Cat 963C won't start

mohamed hodroge

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fest777

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sawmilleng

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Simon C

Senior Member

mohamed hodroge

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mohamed hodroge

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Mobiltech

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mohamed hodroge

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Simon C

Senior Member

Simon C

Senior Member

MyMRO

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Simon C

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