My continuing misfire issue's, I think I figured it out...BUT

[bjtheman1]

I still need some more help.

I believe I finally narrowed down the sources(s) for all my fuking problems!

With the engine idling I disconnected a fuel injector connector one at a time, each time the idle got worse. First thought was I finally figured out it was bad or dirty injectors....wrong!

I did a noid light test to the injector connectors and I got NOTHING! I thought maybe the light was bad so tried it on a coil and got some light so there went that theory.

Soooo, looks like an electrical issue with the fuel system. How in the hell do I figure this one out???

[LS1Goat]

Have you considered getting rid of it at this point? Seems to be nothing but a headache.

[bjtheman1]

Have you considered getting rid of it at this point? Seems to be nothing but a headache.

LOL, even though that thought has crossed my mind many times it's just b/c I'm not mechanically inclined as much as I'd like to be. LOL

Plus, it will be paid off in about a year too

[shumpertdavid]

Some of the newer vehicles, I don't know which ones or where you'd look to find the info, will shut the injector driver down when using a noid light. The bulb in it doesn't match the resistance of an injector and it will disable that cylinder thinking there is an error.

The idle will get worse each time you unplug an injector because you killing the fuel supply to that specific cylinder. You are looking for the one that the idle doesn't change on, when unplugged, as that cylinder won't be contributing to the running of the motor.

You are going to find at some point, just like we auto repair guys do, that your data logging isn't going to point you in any real direction of the problem. Its just like scanner data, and while it's a very useful thing, it doesn't always help with the problem. You have things like cam timing and mechanical issues that the data won't always point to.

[Mach1]

Oscilloscope

[shumpertdavid]

If you are concerned about an injector not firing, leave them plugged in and use a stethoscope to listen for the pintle to cycle on each cylinder. From there if you have one not clicking/firing, like Mach1 said, a labscope would be your next choice to look for a signal from the ecm.

[JC316]

If you are concerned about an injector not firing, leave them plugged in and use a stethoscope to listen for the pintle to cycle on each cylinder. From there if you have one not clicking/firing, like Mach1 said, a labscope would be your next choice to look for a signal from the ecm.

This. Listen for the intensity of the clicking, if one sounds weaker, that is your bad one.

[01lightning]

Have you checked your coils?

[bjtheman1]

Some of the newer vehicles, I don't know which ones or where you'd look to find the info, will shut the injector driver down when using a noid light. The bulb in it doesn't match the resistance of an injector and it will disable that cylinder thinking there is an error.

The idle will get worse each time you unplug an injector because you killing the fuel supply to that specific cylinder. You are looking for the one that the idle doesn't change on, when unplugged, as that cylinder won't be contributing to the running of the motor.

You are going to find at some point, just like we auto repair guys do, that your data logging isn't going to point you in any real direction of the problem. Its just like scanner data, and while it's a very useful thing, it doesn't always help with the problem. You have things like cam timing and mechanical issues that the data won't always point to.

You were right, a website I read info from stated the opposite of what you said. I checked some others and confirmed your answer.

Well, my injectors all showed a 12.5 resistance. I verified correct 12V to the harness and listened to the injectors pulses. Some of them do sound a bit different than the others, slower in my opinion.

I'm just trying to check anything/everything I know how and can figure out how to do to fix this. I'm not great at this stuff but I'll learn...Just have no clue WTF is wrong???

[bjtheman1]

Have you checked your coils?

Oh yea, coils have been checked multiple times.

[Mysticcobrakilla]

Didn't you have a high voltage issue a while back?

[bjtheman1]

Didn't you have a high voltage issue a while back?

It was a crazy voltage loss here/there but in the end it was just a loose wire from the connector at the alternator. Definitely those symptoms back then were not like these currently.

[Lone Star Performance]

Why not just replace all the injectors? I understand not throwing money at a problem in hopes of a fix, but you seem to have narrowed it down to one or multiple weak injectors

[bjtheman1]

Why not just replace all the injectors? I understand not throwing money at a problem in hopes of a fix, but you seem to have narrowed it down to one or multiple weak injectors

I'm hoping I've narrowed it down, this is going to suck if replacing them doesn't change anything

[davbrucas]

My 04 KB cobra had similar issues and the coil packs all checked out fine when tested. I chased the issue for a while and just replaced the coils on a hunch and the problem went away.