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Jay
Jay, Nissan Technician
Category: Nissan
Satisfied Customers: 19620
Experience:  20+yrs experience with Nissan & Infiniti Trained & Certified.Currently still working for Dealer
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2002 NISSAN SENTRA NO SPARK BUT HAVE INJECTOR PULSE

Customer Question

2002 NISSAN SENTRA NO SPARK BUT HAVE INJECTOR PULSE
Submitted: 5 years ago.
Category: Nissan
Expert:  Jay replied 5 years ago.

Jay :

Hello and thank you for using JustAnswer.com

Jay :

Do you know if you have any codes?

Customer:

NO CODES

Jay :

How did you determine you have no spark?

Jay :

If you have injector pulse, then your computer is getting the signal from the crank and cam sensor.

Jay :

So I would double check to be sure your not getting spark.

Customer:

PULLED COIL ON PLUG OUT AND INSTALLED SPARK TESTER INTO COIL

Jay :

Other wise, you could be looking at a ecm

Jay :

what kind of spark tester?

Customer:

KD OFF THE MATCO TRUCK ALSO TRIED TO LOOK AT WAVEFORM OR SIGNAL FROM ECM AND CANT SEEM TO GET ANY

Customer:

USING A VANTAGE SCOPE FROM SNAP ON

Jay :

Well if you have injector pulse, you should be seeing some sort of signal

Jay :

The pulse is given when the computer can determine engine position.

Customer:

I HAVE INJECTOR PULSE BUT NO SPARK I EVEN HAD NISSAN TEC FROM DEALER HERE IN JAX COME DOWN AND CHECK WITH CONSULT BUT COULD NOT DETERMINE FIX

Customer:

MOST TECHS ARE TELLING ME TIMING IS OFF BUT IF IT WAS WHY WOULD I HAVE INJECTOR PULSE AND NO SPARK ALSO THIS VEHICLE HAS NO SECURITY

Jay :

Then I would start suspecting a Ecm problem if the timing is correct

Customer:

WOULD YOU KNOW WHERE I CAN SEE A CAM AND CRANK WAVEFORM TOGETHER TO VERIFY MINE IS CORRECT

Jay :

These engines are known to jump time, I would pop the top timing cover and valve cover off, and put the engine at TDC to verify the timing is correct

Customer:

HAD THAT DONE A FEW DAYS AGO AND ALSO REPLACED INTAKE VVT GEAR ON CAM DUE TO ANOTHER TECH TOOK IT APART

Jay :

Then if your timing is correct, then I can give you the ECM terminal layout and references to see if you can isolate a fault. But I would start suspecting a Ecm if the timing is correct.

Customer:

WHAT TYPE OF SGNAL WOULD I LOOK FOR AT THE TRANSISTORS

Customer:

I HAVE VERIFIED I HAVE 12 VOLTS AND GOOD GROUND AT ALL COILS BUT NOT SEEING ANY TURN ON FOR COIL

Jay :

The Ecm has to see some sort of signal for it to produce injector pulse.

Jay :

The injectors and the coils share the Cam and Crank sensor signal

Jay :

to determine engine position and to help produce pulse and spark.

Jay :

if your not getting spark, then I would suspect you may have a Ecm issue.

Jay :

The Ecm's from 2000 to 2003 were known to have some issues, and did fail quite often.

Customer:

CORRECT I AM WATCHING CAM AND CRANK SIGNALS (SQUARE WAVEFORMS ) BUT IF THEY DONT LINE UP CORRECTLY WOULD I LOOSE SPARK ONLY. I HAVENT FOUND ANY GOOD WAVEFORMS TO VIEW AND I HAVE TRIED A USED ECM FROM A DONER CAR AND HAVE THE SAME RESPONSE INJ. PULSE BUT NO SPARK

Jay :

I would try checking all the ecm reference values to see if you find something out of spec. Click HERE to download it.

Customer:

WILL TRY IN THE MORNING (HOPEFULLY SHOP HAS ADOBE SO I CAN SEE VALUES/REFERENCES

Jay :

ok

Jay :

I am normally online in the evenings after 7pm

Jay :

till 10 or 11 pm EST.