bleach67

I found the problem with my 1990 Nissan 240SX KE24E SOHC. All four injectors are getting only 8-9 volts only when cranking, there is a pulse from the ECU however it's very weak. the Multimeter shows 8-9V across the plug, but shows a full 12v when you use the battery NEG.

The battery is new fully tested and works flawlessly. Always charged at night.

What the heck? I have probed everywhere I can, in the injector harness and relays. 12v.

Any ideas, I am stumped.

I got the car from the old owner, like this.

jbjslambert

the injectors have 12 volts connected all the time, its the ground from the ECU that is pulsing. That pulse is so quick that most multimeters will not display the entire 12volts.

This car doesnt run?

Ohm check the injectors. should be in the neighborhood of 12 ohms. If it was me i would pull the rail and crank the engine with it laying upwards and look to see if you are spraying fuel. if it is, then move on, thats not the problem...

if they dont spray then ohm out the ground wire from the injector plug to the ECU plug. but i dont think this is the problem, not on all 4

Rustys14

I agree with the above. Definitely check the OHM readings on the injectors. Per the 89 FSM the injectors should read between 11 and 15 OHMS. I was having injector problems with the SOHC in my beater car last week and all 4 injectors read 14.6 OHM when measured. My problem ended up being corrosion on the injector terminals causing a week signal. I cleaned the terminals with a baking soda and water paste (the same you would make to clean corroded battery terminals) and the car runs good as new.

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bleach67

No the car doesn't run. I have a NOID light, it is very weak. that is when I used the multimeter. If I remember I think I OHM the injectors, 12 OHM or 13 OHM. I will recheck.

However, I didn't think about corrosion.