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Daniel Wilson
Daniel Wilson,
Category: Medium and Heavy Trucks
Satisfied Customers: 4647
Experience:  Owner at DJ Wilson
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N14 shuts off and wont restart sometimes. getting to the

Customer Question

n14 shuts off and wont restart sometimes. getting to the point where we cant use it.
JA: What's the make/model/year of your truck? Engine type?
Customer: 93 int. 9300 . n14 cummins celect
JA: Are you fixing your truck yourself? What have you tried so far?
Customer: have fuel pressure. new cam sensor and harness. have send ecm away and seems fine they said. just wont fire injectors
JA: Anything else you want the truck mechanic to know before I connect you?
Customer: no
Submitted: 4 months ago.
Category: Medium and Heavy Trucks
Expert:  go-west.. replied 4 months ago.
Good evening
Does the check engine light ever come on? Have you checked battery and switched power?
Customer: replied 4 months ago.
no engine light. replaced unswitched power harness. new batteries. have 12 volt at fuel solenoid. injectors wont fire. can fuel pressure stop injectors from firing? have a noid light plugged in
Expert:  go-west.. replied 4 months ago.
If there is at least 130 psi coming out of the fuel pump you're good, what are you getting -?
Customer: replied 4 months ago.
150 when it runs. 30 at cranking. is there a fuel pressure sensor that keeps injectors from firing? i was told that injectors should fire no matter what the fuel pressure is.??
Expert:  go-west.. replied 4 months ago.
No sensor
It's good the the battery and ground circuits have been eliminated but the switched circuit should be checked next.
Customer: replied 4 months ago.
have 12v at fuel solenoid. does that not mean that switched power is working. gauges also swoop
Customer: replied 4 months ago.
sweep i mean
Expert:  go-west.. replied 4 months ago.
Gauges sweep when it faults?
Customer: replied 4 months ago.
when i turn the key one click...gauges sweep...then go to crank and it wont start
Expert:  go-west.. replied 4 months ago.
Disconnect your alternator belt, i just want to confirm thats not your issue I've seen altetnators cause this
Customer: replied 4 months ago.
will do tomorrow. how would an alternator cause this?
Expert:  go-west.. replied 4 months ago.
They sometimes create electronic noise that can corrupt the ecm.
I've seen about 3x
Customer: replied 4 months ago.
took alt. belts off. still no fire.
Expert:  go-west.. replied 4 months ago.
Interesting
I'll opt out and see if another expert can help.
Expert:  Daniel Wilson replied 4 months ago.

Hi my name is***** will be glad to try to help. If you have confirmed all your Battery and switched powers and ECM grounds are good, battery has full voltage supplying the ECM, and the Engine position sensor is getting signal to the ECM ( no sensor, harness, or signal issues) then I recommend coming up with a test ECm from another truck to confirm the current ECM is good. It sounds like the fuel system checks out okay as well. All points to an ECM issue. Let me know

Customer: replied 4 months ago.
sensor harness is new. we ohmed out cam sensor and it seems ok. if we had a fuel issue... should ecm still fire the injectors. it doesnt know if engine is getting fuel right?
Expert:  Daniel Wilson replied 4 months ago.

id verify the EPS sensor is actually sending RPM signal to the ECM. It is possible it is not picking up signal from the gear to fire the injectors. Have you removed the sensor and cleaned and inspected the tip?

Expert:  Daniel Wilson replied 4 months ago.

The fuel shutoff is powered and turning the fuel on correct?

Customer: replied 4 months ago.
we did. ohms change on it as we crank
Customer: replied 4 months ago.
we have a noid light plugged into a injector wire. it wont light up. thats not fuel related is it?
Expert:  Daniel Wilson replied 4 months ago.

Not at all.... That is failed ECM injector drivers id the ECM has all its powers and grounds and you are 100% sure the EPS is sensing RPM signal to the ECM.

Customer: replied 4 months ago.
how do we check eps for signal?
Expert:  Daniel Wilson replied 4 months ago.

The EPS ( cam sensor) can check good but still be bad. Check the connector for oil intrusion and remove the sensor to inspect for check for damage, bubbles and cracks in the face of the face of it. It should ohm out at 1500-2000 ohms . They will fail both hot and cold. Cummins Insite connected reading live data will show if EPS signal is missing.

Expert:  Daniel Wilson replied 4 months ago.

Or just replace the sensor if the harness tests good.

Expert:  Daniel Wilson replied 4 months ago.

If there is still a problem you are looking at an ECM issue.