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Jake, Nissan Technician
Category: Nissan
Satisfied Customers: 4279
Experience:  Experienced collision repair technician, Pulaski Tech graduate and DSM hobbyist.
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Why would the computer switch off the injectors at idle?

Customer Question

Why would the computer switch off the injectors at idle?
Submitted: 4 years ago.
Category: Nissan
Expert:  Jake replied 4 years ago.

Jake : Hi there
Jake : generally the injector pulse is only cut if there is no key recognition
Jake : or no crank position signal
Jake : But why they would work at higher RPM's and not at idle doesn't make much sense
JACUSTOMER-80b323yv- :

I agree

JACUSTOMER-80b323yv- :

Could it be a faulty computer?

Jake : Are you still getting a TPS signal at idle?
Jake : Generally if the ECM was at fault they wouldn't get a ground pulse at all
Jake : so probably not the ECM
JACUSTOMER-80b323yv- :

I can see it on the scan tool. Sensor 1 = .38mv and sensor2 = 0.76mv

JACUSTOMER-80b323yv- :

I have compared all of the scan tool data with a know good van and all parameters are the same except the battery voltage and fuel pressure.

JACUSTOMER-80b323yv- :

Could this be a ground issue?

JACUSTOMER-80b323yv- :

The battery is good and charging system ok.

Jake : Hmm that's peculiar indeed. Did you try bleeding the fuel system just in case?
JACUSTOMER-80b323yv- :


JACUSTOMER-80b323yv- :

But I have driven it for miles

JACUSTOMER-80b323yv- :

However I was thinking of doing that

Jake : It might be an issue with the fuel pressure sensor causing the ECM to cut injector pulse.
Jake : If pressure readings are the only thing off at this point
JACUSTOMER-80b323yv- :


Jake : Try bleeding it off, to see if that helps.
JACUSTOMER-80b323yv- :

How is that done?

Jake : You can do it by moving the priming pump up and down, or removing the feed line and operating the electric pump
Expert:  Jake replied 4 years ago.

If you need more help, please just let me know.

if not, just please leave a kind rating.