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Matt
Matt, Engineer
Category: Nissan
Satisfied Customers: 20611
Experience:  BEng hons Mech engineering, worked in auto industry for 22 years on engine, transmission and suspension design
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Nissan Z32: On my 1993 300zx non turbo, I just updated to newer

Customer Question

On my 1993 300zx non turbo, I just updated to newer 94 style injectors. But now the new injectors are burning out. Voltage to injectors is 12.5 with the car not running and 14.5 running. They are controlled by ground single.
Submitted: 1 year ago.
Category: Nissan
Expert:  Matt replied 1 year ago.
Hello the crucial thing to check here is the resistance of the old and new injectorsmost modern injectors are 'high impedence' so reducing the amount of current they pull, however if your new injectors are low impedence ( about 3-4 ohms as opposed to 12-14ohms) then they'll pull a lot more current and so burn wiring etc so check the two resistances as the next step and try an match the original injector resistance / impedence
Customer: replied 1 year ago.
Old and new are the same. Thank you.
Expert:  Matt replied 1 year ago.
HelloOK in that case I'd check the condition of the small engine earth connections that run out of the loom and are terminated onto the engine block with ring terminals - these are the specific earth paths for the ECU
Customer: replied 1 year ago.
Yes all grounds look good.
Still burning out injectors. Thank you.
Expert:  Matt replied 1 year ago.
Hello I'd next check that the new injectors are polarised the same way as the old? if you check on the connector plug there should be a '+' sign to show which side is which
Customer: replied 1 year ago.
I do not see + or - on the injector, but it's red wire has positive voltage.
Thank you.
Expert:  Matt replied 1 year ago.
HelloOK can you tell me the make and model number of the old and new injectors ?
Customer: replied 1 year ago.
Old injectors were oem 1993 300zx na red top injectors, new injectors are oem 1994 300zx red top injectors.
I don't see part numbers on them. Thank you.
Customer: replied 1 year ago.
New Replacement cyl 3 injector is activating/clicking but pulling off connection dose not alter idle, unlike disconnecting any other cyl injector.
Expert:  Matt replied 1 year ago.
Hello
in that case I'd measure the resistance of the wiring back to the injector as there must be a short somewhere on that injector signal