Help: head gaskets changed now big problem

J

jason86

Marv
Dec 30, 2008
78
0
6
Sacramento, CA
ok guys i changed out my head gaskets today along with two injectors and now the truck starts but its only running on 4 cylinders. im getting codes p0201 p0204 p0206 p0207 and p2146. i can guarantee all the leads are hooked up to the injectors under u valve cover and i went through the bale connectors and pulled all the pins to make sure that wasnt the problem. i checked all the connections and they look good and secure. also i have no reading of oil pressure on the gauge, funny thing is the display doesnt say "check gauges".

also i have 2 connectors that have no home. 1 is the yellow multi connector that is next to the bale connectors with about 3-4 inches of reach it looks exactly like the glow plug connector but that plug is connected and the the reach is no where close and i have no idea where its supposed to go. the other looks like a ground terminal and i checked it with a test light and it has no power. its not the glow plug connector or the ground its too small to fit onto any of the firewall ground connections and i have no idea where it goes.

any help will be much apperciated fells my truck is stranded and my family is hurtiing till i get this figured out.

here is a picture of the plug and wire.
 

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05_LLY

05_LLY

Out-A-Time
Aug 7, 2006
1,756
1
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Norvelt, PA
THe plug is for your oil pressure also carrys a few ecm grounds, it plugs in just below where your holding it on top of the y bridge drivers side, the other end that plugs into it comes up from the passenger side bottom side of the engine, is supposed to be routed behind the coolant bridge and behind the accessory bracket! the heavy wire is either for the grid heater on the intake or the first glow plug on either side!
 
05_LLY

05_LLY

Out-A-Time
Aug 7, 2006
1,756
1
36
43
Norvelt, PA
The inj codes are either from a loose wire, plug or possiably the harness pinched between the valve covers on eiother 1, 4, 6, 8!
 
JoshH

JoshH

Daggum farm truck
Staff member
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Feb 14, 2007
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That wire with the small ring terminal looks like the wire that goes on the #2 glow plug (the front cylinder on the driver's side) that carries the power across to the glow plugs on the passenger's side. And like Caleb said, the plug goes to the harness that runs down to your oil pressure and oil level sensor.
 
J

jason86

Marv
Dec 30, 2008
78
0
6
Sacramento, CA
dammit.........

ok im dumbfounded. i checked the harness from the bale connectors to the ficm for grounds to short all is good.

checked the injector harnesses and all were good with no open circuits and all had good resistances.

checked all the fuses and relays all were good.

i did the flowchart and the only thing i can find is that there is no power to the ignition voltage circuit but there is power at ignition 1 voltage (the pink wire). so i check the coorosponding pin in the bale connector and no power there either so i check the fuses and relays again surprise all are good. i dont know if because the code is set that power is cut off from even going to that circuit or what.

clear the codes start it up and boom it only starts on 4 cylinders and all the codes are back.

any ideas guys.
 
JoshH

JoshH

Daggum farm truck
Staff member
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Feb 14, 2007
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jason86 said:
ok im dumbfounded. i checked the harness from the bale connectors to the ficm for grounds to short all is good.

checked the injector harnesses and all were good with no open circuits and all had good resistances.

checked all the fuses and relays all were good.

i did the flowchart and the only thing i can find is that there is no power to the ignition voltage circuit but there is power at ignition 1 voltage (the pink wire). so i check the coorosponding pin in the bale connector and no power there either so i check the fuses and relays again surprise all are good. i dont know if because the code is set that power is cut off from even going to that circuit or what.

clear the codes start it up and boom it only starts on 4 cylinders and all the codes are back.

any ideas guys.
Click to expand...
What were the resistances on the injectors? Do you have another truck you could borrow an FICM from?
 
J

jason86

Marv
Dec 30, 2008
78
0
6
Sacramento, CA
Injector resistances are all around .5 ohms.

Fingers I have reset and checked those plugs many times to no avail.

If you trace the b+ ignItion voltage from the ficm to the bale connector the pin in the housing from the fuse box that it connects to ignb has no power to it. Is that normal? I have power at ignition 1 voltage just not the pin b+ the flowchart says should have power to it.
 
Fingers

Fingers

Village Idiot
Vendor/Sponsor
Apr 1, 2008
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White Oak, PA
OK. The power from the Fuse block splits prior to the bale connector into two pink wires. You're supposed to have power at the bale connector at locations A4 and A5, both pink. Sounds like you only have power on one of these. Check both sides of the bale connector. Pierce the wire insulation to check.

If power isn't getting to the bale, then you might have a broken wire from the fuse block. The two wires merge under the fuse block. If you have power there, but not at the bale, you might have to run a new wire.
 
Fingers

Fingers

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If you roll the fuse block over. (it's hinged) the wires are in location D9. Should be two pink wires going into the same spot.
 
J

jason86

Marv
Dec 30, 2008
78
0
6
Sacramento, CA
fingers, the flowchart says to check the orange white wire for power not the pink wire. the pink wires have power at every connection. the orange wire has no power. am i reading the chart wrong?

also unfortunetly no I don't have access to another lb7 ficm. only lbz and later.

also resistences from the ficm plug with injectors connected and at the injector harness just by itself are all pretty close at around .5ohms or so.

what are the chances that a ficm would go bad in this way when it was working perfectly fine before the head gaskets and the 2 injectors that are working on the other circuit.
 
Fingers

Fingers

Village Idiot
Vendor/Sponsor
Apr 1, 2008
1,718
96
48
White Oak, PA
The Pink wires are supplies into the FICM. The FICM uses a split supply. One for each bank of injectors. You need to check that power is getting to the FICM on both lines.

C107 in the attached schematic is one of the bale connectors on the engine.
 
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J

jason86

Marv
Dec 30, 2008
78
0
6
Sacramento, CA
still not good

okay i am back from vacation and i just now got to look at the truck again. i checked the pink power wires at both ficm connectors and there is power to both of them. i have no idea where to go from here. i checked all the injectors at their respective pugs at the valve covers and they were all the same with no opens or exorbenant resistences.
i need the truck for work and this is going to cause a big hardship on my bank and family. anyone have any ideas where to go from here?
 
J

jason86

Marv
Dec 30, 2008
78
0
6
Sacramento, CA
Well after checking again it seems #6 injector which i didn't change has a short to ground on both posts at the injector harness at the valve cover. So I guess I get to change that injector now because I can't imagine it being the harness being both wires.
 
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