please help injector wiring problems 2002 duramax

[2001 max]

I have a 2002 duramax that just randomly started acting up I plugged my efi live in and the balance rates in park are 7.00 on one side and 15.00 on the other side and they don't move it sounds like a tractor the rail pressure is at 5600 or so, the truck is an 2002 Silverado 3500 lb7 no tunes or anything it had new injectors about 15k ago please any ideas would be great thanks I need to get the truck up and running by Monday night I have seen a couple of posts where people have the same problem but no one has posted the answer if you could help id appreciate it

 

[dirtydmax]

1 whole bank is +15?Could be the plugs not seated properly.

 

[OregonDMAX]

Did you just fuel up? A bad tank of fuel(full of water, sediment from tye bottom of tue tank) can do crazy things

 

[The Neens]

I plugged my efi live in and the balance rates in park are 7.00 on one side and 15.00 on the other side and they don't move

I'm not doubting that you have an issue, but if the balance rates are exactly 7.00 and 15.00 without moving, there is also a data recording issue...

 

[2001 max]

I just pulled the passenger side valve cover off and checked the connections and everything looked good nothing unusual, and yes there exactly 7.00 and 15.00 and no not move that's what makes me think its wiring somewhere, I read that the duramax will do this when it senses dome sort of problem goes into a 4 cylinder mode of some sort I have found 3 other threads that were dead end threads with no fix recorded

 

[onebaddmaxxx]

Had this happen when someone had a cheapo fuel filter on and dirt when thru the system and got stuck inside the injector. Just plan on replacing the injectors showing bad. If you got the from gm they have a year warrenty.

How's the life of the cp3? If its old and wore out metal coulda went thru the system also

 

[TheBac]

I'm not doubting that you have an issue, but if the balance rates are exactly 7.00 and 15.00 without moving, there is also a data recording issue...

Id be starting here, too. You arent getting accurate data in the first place so you cant make an accurate diagnosis.

 

[2001 max]

The truck is running like it's only on 4 cylinders knocking (fuel) and won't Rev past 2000 rpms

 

[The Neens]

Did you just fuel up? A bad tank of fuel(full of water, sediment from tye bottom of tue tank) can do crazy things

The truck is running like it's only on 4 cylinders knocking (fuel) and won't Rev past 2000 rpms

Have you opened the drain on the fuel filter to see what comes out?

 

[2001 max]

I changed the fuel filter first thing so I know it's all new

 

[farmtrucklb7]

I had pretty much the exact problem. I just switched injectors I'll let you know when I get it running again but I did find 3 pinched o rings from the previous owner. Mine had 7000 miles on the set...

 

[2001 max]

From the information I have gathered whenever there is a short to ground or an open circuit it shuts off 4 injectors

 

[kidturbo]

Yep... 100% a injector plug is flaking out and ya dropped 4 cyl.

 

[farmtrucklb7]

keep me updated on what you find. I put in new injectors and I still have the same issue. its exactly the same as yours. I have switched ficm, both cp3s including regulators, fprv with no improvement, if it turns out to be an injector plug I will be beside my self with joy..... im getting very frustrated lol

 

[onebaddmaxxx]

I had pretty much the exact problem. I just switched injectors I'll let you know when I get it running again but I did find 3 pinched o rings from the previous owner. Mine had 7000 miles on the set...

O rings being pinched/ripped/tore do not effect anything on drivability. They simply are supposed to keep dirt from falling down the bore. The line seals from the flares on the lines/tops of injectors. Of course with lb7s, if your not siliconing the tops of the injector line fitting by the heads, you may as well just pee in the wind :thumb:

Also, when you have your valve cover harness, look at the wires as they sit in there. the little clips that hold the wires on the solenoids are super known for breaking and the wires aren't that snug. they kinda have the ability to move around and rub things. Pull the valve covers and put the lines back on, then start moving injector wires around and see if anything changes. Hope this helps :hug:

 

[ecc_33]

Just ohm out the injector harnesses. Its really simple to do and will tell you if you have resistance in the wire.

 

[farmtrucklb7]

When it is on an idle go threw and Shut off each injector individually I found my 6-7 were not firing turned out to be electrical. In the wiring diagram it shows that 6 and 7 are grounded slightly different then the other 6. I'm not convinced this is the last time I see my issue but it's running good now. I am replacing my entire harness this winter it's been apart one to many times it's not very pretty looking like the one I have on the bench. Hope this helps

 

[farmtrucklb7]

So I found that my reluctor wheel on the crank was loose

 

[Bustedknuckles]

So I found that my reluctor wheel on the crank was loose

Wow, had did you pinpoint that? Ive heard of that happening but normally the truck just shuts off.

 

[farmtrucklb7]

It wasn't wildly loose but I can move it with a screw driver. It was the last thing left. I switched everything else. I'm done banging my head against the wall for now, I'm thankful my father in law helped me out this week with his fancy scope. Now to tare it apart, hope I can get back pulling for next weekend