chitown21y

iTrader: (6)

So the new V has a missfire that I cant find after hours of trying. I know that its the #8 cylinder because the engine does not change tune if I unplug that injector. I have changed plugs, wires and coils with no change. The dealer confirmed that its a dead missfire in #8 also. Any idea how to see if the injector is getting voltage to it?

What else do you guys think I should check?

Any help would be great!

Thanks Dave...

RedHotG8

iTrader: (1)

If you changed plugs, wires and coils then it must be a bad injector. If the dealer confirmed it's on #8 why didn't they tell you what the problem was?

chitown21y

iTrader: (6)

I took it to the dealer to have them re program the new pcm I had to install due to the old one being bad. Same problem before and after along with 150 bucks. They wanted another 150 to diagnose the miss. I thought I could figure it out before forking out another lump of cash. Going to go try and switch the injector now and see if it changes the miss. Thanks!

RedHotG8

iTrader: (1)

I think you need to find a new dealer, it sounds like they are giving you the shaft.

chitown21y

iTrader: (6)

I agree.. Just switched injectors and still the #8 cyl is still missfiring. The injector is not firing. I am stumped on this one?

RedHotG8

iTrader: (1)

It must be an electrical problem then, and those are tough to track down. You will need a professional to find the problem.

65panel5.3

if you can get access to a noid light plug it into number 8 injector harness, this will test to see if the circuits are good its a good way of double checking both the power and signal side of the plug,if nothing check for power at the injector with a test light, should be 12v with key on. if not then jump 12v to it and see if the injector comes alive, also check the signal side of the plug with a digital test light. if nothing there then check right at the pcm... could be wire to the injector or possibly a pcm problem. somewhere to start if you feel comfortable doing so.

chitown21y

iTrader: (6)

Ok I have the problem narrowed down to the #8 injector signal wire. I tested the blue and white wire from that injector to the plug at the pcm and there is no connection. So I guess the wire is broken somewhere? I verified that the injector next injector plug (#6) has the connection at the pcm.

Are the injector signal wires wired to the pcm without a fuse?

If so I guess I will be tearing the entire harness apart to find it....uhhhh

xxrillixx

iTrader: (118)

Its odd that the one wire would just go 'bad'. You usually dont see that unless its burn or cut. Which is a dead give away. First thing i would do is visually inspect the wire. If you dont see anything..

I would check it by running a test wire, as short as possible to just make sure you can get the injector firing before making it look nice. If that works...

1. Just replace the entire run with new wire, and not worry about finding the broken spot.

Or 2. if you dont want to replace the whole thing and want to spend the time finding the broken spot, just do 'halves'. You said PCM to INJ had no connection. So next check half way. If you have signal then move half way towards the inj, if not move half way to the pcm. Should help narrow it down faster then picking arbitrary spots to check.

Good luck man, sounds like your on the right track.

chitown21y

iTrader: (6)

Good points.. I am thinking about just running a new wire but I need to know if its wired straight to the pcm or is there a fuse or anything else wired in? Just want to make sure I do it right. Thanks !

scatillac

iTrader: (12)

The pink side is fused with all the other even injectors and provides constant 12v in start/run. There is a soldered bridging connection that splits the circuit between the fuse and the injectors

The other side of the injectors are connected to ECM injector controllers that ground the injectors when it's their turn to fire. The #8 injector is wired directly to the ECM via pin 77 in connector C1 (Blue). It should be a dark blue/white wire.

(1) Check for 12V on the pink wire side of the injector plug. If you don't have it there, it's likely broken at/near the bridging connector or at the ECM connector.

(2) If you have 12V on the pink wire, then the grounding circuit side is the culprit. Since this is an uninterrupted wire, check the circuit's ends closest to their respective connectors and the connector pins themselves (with an ohmmeter, if available). If it's not there, then you would be better bypassing the wire altogether.

(3) Open a cold one after the problem is solved.

65panel5.3

id agree on inspecting for damaged wires and burnt wires etc. if nothing then running a new wire would be your easiest way to go, if you do a nice clean install then you should never have any problems.

chitown21y

iTrader: (6)

I did a nice clean install with a new wire and she runs like a champ now. I love the car minus the wheel hop..LOL

Thanks for all the help !

Dave..