Injector not working

Good morning,

Did you verify power to the injector itself when it is not working?

Also, you need a noid light to be sure the quad driver in the ECM is commanding it to allow fuel.

The other possibility is dirt in the injector.

Roy

I wasn't able to yesterday because I didn't have a volt meter and it was raining, is there any other way to test it without a noid light? Because when I changed the plug to begin with I wasn't getting a hot reading on either side of the the plug. But like I said it was working fine after I changed the plug and then it just quit while I was driving it. I been doing a lot of research and I been seeing where there is something in the distributor that it's suppose to read also .

No, there is not. The distributor does send a signal to the ECM but if the other one works, that is not the case.

You can use a test light. With the connector unhooked from the injector, put one lead into one side the other lead into the other terminal and crank it and see if it flashes.

Roy

Okay, I will try that this evening. I just don't understand why it goes in and out, I do mechanic work but most of my experience is in diesel so I'm trying to learn this in the process. And I will say the service engine light came on a couple times and then went off. Can I retrieve a code from it, I seen another post where someone said to out a jumper wire in the obd1 plug and it will give me a code. Is that true?

Yes, you can. You jump 2 pins on the data link connector at the top right of the connector. It will flash codes. 12 will be the first and then the actual code will flash after that.

This could be a bad ECM which was common on these old OBD1 systems.


Roy

That's what I'm really starting to think is it's the ECM, I really hope not but I just got to figure it out. I know it's not the injector itself cause I can swap the plug and the injector works fine.

Okay, do the test and let me know. The ECM is cheap and is a plug and play.

Roy

Okay, will do. appreciate all the help.

You are welcome.

always glad to help.

Roy

Well I tested the injector when I got to the truck and sure enough it's not getting a ground signal when trying to crank or while the truck is running, so I guess it's on to the ecm, where is it located and how can I test it to make sure before I go get one .

Okay, It is under the right side of the dash. I attached procedure and pictures for you to view.

You cannot test it. It takes special equipment to actually test the internals.

Roy

Okay, I been reading some stuff about a prom what is that exactly?

A prom is a chip with all the vehicle information. You will change that over from the old ECM to the replacement ECM.

Roy

Okay, will anything need to be programmed or anything or is it already programmed?

And is the prom inside the ECM or what? I've never messed with one before.

There is a cover with 2, 1/4 inch bolts and the cover comes off. The prom is a circuit board that you depress the ends and it comes right up. Takes you about 5 minutes if you take your time. Just push the new one into the replacement and install the cover.

Roy

Okay, does a prom ever go bad? if so how can you be able to tell?

Yes, you can tell when it does not run at all. When that happens, you replace the ECM and prom at the same time.

Roy

Okay, well I guess I will be getting a ECM. thanks for all your help.

I pulled the ECM out this morning and under the cover I have to different do I need to reuse both or just one?

Okay, the other is a cal pack. Yes, change that over as well.

Roy

Okay, when I pulled the ECU I noticed a couple corrosion or hot spots on the ECM plugs, cleaned them and it's running fine so far.

Okay, good. Let it go for now before you replace the ECM.

Roy

I am, but I'm looking at it and one injector is spraying a lot more than the other. what can cause this and what do I need to do to fix it?

That is controlled by the ECM. The injector on time is determined and controlled by the ECM. You may still have a bad ECM.

Roy

Driver side injector is spraying just a little bit at idle, passenger side is really spraying a lot. But I don't know which one is spraying the correct way.

And how can I tell if this is the vortec motor or not?

A vortec is a multi port engine which has an injector for each cylinder.

You would need a advanced scan tool to monitor the injector on time.

Roy

Okay, well it's definitely not a vortec then.

Nope, way too early.

Roy

Okay, well I was just doing some research and I come across something that said due to the firing order or timing of the v6 one injector sprays more than the other, is that true? My thinking is that both should spray the same.

No. As usual more inaccurate information from the internet.

It is all ECM controlled based on inputs and strategies.

Roy

Okay, I was wondering cause it didn't make sense to me, but one thing I'm going to have to do is get better fuel mileage.

Most likely not. With 2 injectors, you will be using more fuel.

Roy

It's got to be something else. I know it's got some messed up exhaust on it that I'm going to be getting fixed, that should help it some because it has no cats or anything just a thrush exhaust.

As I stated before, this could be and most likely is the ECM itself.

Roy