Injector stops working

[Jetblack]

Every now and then one of my injectors loses voltage and throws a CE light and what not for a misfire. I was finally able to verify which injector and that it wasn't getting voltage. I can shut off the engine and restart and the voltage would come back. Any suggestions on how to remedy this intermittent problem?

 

[GVR4592]

How did you verify that it isn't getting voltage? Or is it just not getting a signal from the ecu? I'd have to check a wiring diagram but I thought that all of the injectors shared a common power source(main efi relay). If only one injector loses power then it's most likely a wiring problem.

 

[steve]

They do share a common power source which is the feed from the MPI to the injector resistor pack. This can go bad, as can the wires and connectors between it and the injectors.

Steve

 

[Jetblack]

While the car was misfiring I pulled the connector on the injector that wasn't firing and measured it against the injectors that were firing. It was getting a little voltage just not nearly as much as the other injectors. It's probably the injector going bad. I'll have to swap it around and see if it goes out in the new location.

 

[eclipsh]

Have you tested the Ohms of resistance on all four injectors to compare? There isn't much inside an injector that can go bad electrically. It is just a solid-state electromagnet.

Double check all your connections, pull them apart and use some electrical cleaner and a scraper on any corrosion and re-test the voltage.

Also try wiggling the harness when you are measuring voltage and see if you can reproduce the voltage drop. You may have a worn out wire somewhere that is losing contact with vibration/bending but can jump some current across still.

 

[Jetblack]

I'll give that a try too, only thing it's so intermittent it's hard to catch it while I'm near the house

 

[eclipsh]

You shouldn't be trying to catch it, you should be trying to reproduce it and isolate it's cause.

 

[GVR4592]

While the car was misfiring I pulled the connector on the injector that wasn't firing and measured it against the injectors that were firing. It was getting a little voltage just not nearly as much as the other injectors. It's probably the injector going bad. I'll have to swap it around and see if it goes out in the new location.

If you disconected the connector and there was low voltage at the connector how could that be the injector?

 

[steve]

What exactly was being measured?
One pin on the connector is from the resistor pack and the other from the ECU. Measuring between the two with a typical voltmeter isn't going to give a very good/usefull reading since the "ground" is pulsing. You want to find the power pin (from the resistor pack) and measure from it to chassis ground.

Steve

 

[ECLIPSERACR102]

Dude, i have an injector that shuts down on the highway, the car shakes, boost is normal, but no acceleration. i was told by a speed shop that they seen the problem before and that a wire needs to be run from the fuel injection to the ecu to trick the computer somehow, they didnt get into detail but they have fixed this before, does that sound like your symptom?

 

[L2RTSiAWD]

Dude, i have an injector that shuts down on the highway, the car shakes, boost is normal, but no acceleration. i was told by a speed shop that they seen the problem before and that a wire needs to be run from the fuel injection to the ecu to trick the computer somehow, they didnt get into detail but they have fixed this before, does that sound like your symptom?

WTF Your "speed shop" people are idiots.

 

[Jetblack]

Reply to Steve ( I don't know how to put your quote in my reply) I probably did measure it wrong because I did measure across the 2 terminals and I don't know how a bad injector could cause electrical issues but I say any thing is possible even when it's not logical. But I used a mechanics stethescope to listen for the injector clicking and it wasn't. Like I said if I restart the car it comes back to life. The car hasn't shaked because fortunately I've been cruising when it happens while trying to get my fuel trims set.

 

[tallywacker]

hahahahaha "speed shop guys" who are these gods that you speak of ROTFL

 

[steve]

Right now I think your plan to swap the injectors around is the quickest way to eliminate the possibility of a bad injector short of just putting a "good" on in it's place.

Steve

 

[ECLIPSERACR102]

Ok, I put a problem up here that i am having to see if it relates to anyone elses and all you want to do is make fun of the speed shop guys? I keep them private because they performed a miracle for me and i dont want people giving them a bad name. They assembled my 99 gsx out of boxes after a shop in slc blew my engine up, car sat for 3 yrs and someone broke in the wherehouse and stole most of my engine components and tranny, person is known. So if anyone of you geniouses know what my problem is, any advice would be appriciated instead of making fun of the speed shop or saying they are idiots. If they are such idiots, what is my car doing then?

 

[steve]

Ok, I put a problem up here that I am having to see if it relates to anyone elses.

If you can't see what the problem was with your post then I feel sorry for you.

If you want help, start your own thread with some real detail about your problem and what you have done to diagnose it.

Steve