My car isn't really running, and today i found that my front primary injector voltage from my ECU is .3 - .4 volts. The wierd thing about it is that my other ECU (exact same serial number) is doing the same thing. Anyone know what inputs screw around with the injector outputs from the ECU? My car is a '87 NA.

 

the ecu grounds the injectors, they have 12v power from the main relay, black w/yellow tracer. if its just one wire, then you have a harness issue

 

where should i go to check the harness? Where does that wire come from? You said that it goes into the main relay. Could that be bad? What suggestions do you have in checking the harness because that is a shitload of wires to check individually.

 

did you back probe the injector connector while it was plugged in? because if you did the injector could be faulty.

 

i probed the back of the ECU at the power wire that feeds into the injector.

 

check for voltage at the injector, if you have none then its a harness/ main relay problem.

also check impedance on the injector, it might be bad

 

okay, i'll check it this afternoon and let you know. i think that my other primary started doing the same thing. I checked it last night, and i got the same readings. Should i check the grounds? Where are the others besides the one that it under the intake manifold?

 

You're not listening to the replies.

The ECU does not send "power" to the fuel injectors.
The power comes from a separate circuit that has nothing to do with the ECU.

It sounds like you have an intermittent wiring problem, and electrical problems are a pain in the *** to diagnose and fix.



-Ted

 

It actually sounds like the solenoid coil in the injector opened (assuming the wiring is good)- .3 or.4 volts might as well be 0v...If the other injectors have 12v at the ECU, consider the main relay good...You're gonna have to get to the injector, take the connector off, and read the injector for resistance. If it's in specs (2-3 ohms or 11-13, depending on lo/hi impedance setup), then the wiring is suspect. If it reads open (no continuity), it's a bad injector...

 

check this out...i think i got it. I took off the primary injectors and looked at their connectors. In each one, there was one wire sticking out of the plastic harness. Problem maybe? lol, i hooked it up and put the thing back together, fired right up; now it won't idle, but i'm thinking that's because i have about 6 open vacuum ports. I also took off the air pump and ACV, maybe that had something to do with the car running, who knows?

 

vacuum leaks will do that..