My guys were changing a valve cover gasket and when going back together they switched one of the injector wires around. The tractor would not start up and blew smoke out the engine air filter. Went back and put the wires the right way and still the same and will not start. Took it to a dealership and the said my motor is wiped out. By the way the tractor was running just fine when they took it apart THE ONLY thing that went wrong was one injector wire got crossed. So they think it needs a new motor because the valves aren’t sealing off and the pistons have play so they say but it has 300 psi in all cylinders. This isn’t adding up. I don’t understand how crossing two wires can mess up a motor but yet the motor has 300 psi in all cylinders?
Crossed injector wire on 9960
- Thread starter Kubota9969
- Start date
Compression should be 448 to 476psi with a minimum of 350psi. If only 300psi it won't start.
So would crossing a wire on one injector cause it to drop down to 300 where it can’t start anymore when I pulled it in my shop it was running just fine?
I have no idea what effect crossing injector wires would have but the WSM specifically advises to be careful not to do it! Something has caused the compression to be low so something in the cylinder sealing must be compromised. ( pistons, rings valves, head gasket, bent connecting rods etc.) I'm guessing here but it might have caused ALL the injectors to go full open, flooding the cylinders and causing a hydro-lock thus bending all the rods!
Can you provide some details/facts here?
You're wording sounds like they disassembled the engine after they determined cylinder pressure was at 300 psi.
Were all cylinder pressures at 300 psi?
Did you authorize them to disassemble the motor?
How did they determine pistons have play?
Which injector wires were crossed? Knowing this, one could possibly give some general assessment as to fuel injection timing and piston position relationship to determine if damage is likely. Based on the low cylinder pressure it seems highly plausible.
Did they give an estimate on replacement cost?
the design of that wiring harness would only allow the wires to be 'flipped" at the injector.( You really couldn't physically get the wires connected to the wrong injector.) What affect would that have? I've certainly never tried it to find out!
More to this saga than is being told I strongly suspect. I'm really curious why the valve cover gasket was being replaced in the first place. In all the Kubota's I've owned, never replaced a valve cover gasket unless I was in the overhead for some reason. They just do't leak.
While I don't know the specifics of the motor, I'm sure Eserve does. Sound to me like it's junk internally, but then what do I know. Not Tier 4 common rail person.
While I don't know the specifics of the motor, I'm sure Eserve does. Sound to me like it's junk internally, but then what do I know. Not Tier 4 common rail person.
Yes they did find out that the cylinders had 300 before they dissembled the motor.
All cylinders were at 300psi
I did not authorize them to disassemble the motor. Now they are covering all labor cost
Cylinder 3 injector wires got crossed
Tractor was running fine when it pulled in my shop just crossed the wire on that one injector when going back together and it ran for 5 seconds then I turned it off
I replaced the valve cover gasket because it was leaking oil down the side of the motor
How can a motor running fine then cross one injector wire and the tractor doesn’t run for 5 seconds and then the motor be wiped out?
All cylinders were at 300psi
I did not authorize them to disassemble the motor. Now they are covering all labor cost
Cylinder 3 injector wires got crossed
Tractor was running fine when it pulled in my shop just crossed the wire on that one injector when going back together and it ran for 5 seconds then I turned it off
I replaced the valve cover gasket because it was leaking oil down the side of the motor
How can a motor running fine then cross one injector wire and the tractor doesn’t run for 5 seconds and then the motor be wiped out?
Is it possible the original mechanics used starting fluid to get the motor running again when they experienced difficulty in starting?
It's somewhat odd all cylinders measured the same 300 psi.
Hope it all works out.
It's somewhat odd all cylinders measured the same 300 psi.
Hope it all works out.
I'm suspicious of that compression reading too! Quite a coincidence for ALL 4 cylinders to be that low and close to the same. Faulty compression tester? Battery low when they were taking readings? So many mysteries here! It will be interesting what happens with this problem. I don't think crossing the wires would damage the engine itself ( might damage the ECU though!) but the terminals on the injectors are marked common and TWV so polarity is important. They run at over 100 volts so who knows where the electrons go if they are reversed?
I also have no experience with Tier 4 engines nor will I ever have any BUT if all injectors wires were attached to injectors then there had to be 2 wires attached incorrectly to injectors not 1. It seems odd to me that fuel being injected at wrong time could affect engine compression.
Something don't add up. Like Paul Harvey said... Now, for the trst of the story. I'll be reading along with a bowl of buttered popcorn......
North Idaho Wolfman
Moderator
Staff member
Lifetime Member
Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Reversing the wires on one injector should not have done anything other than maybe fault out that injector.
When they did the valve cover, did they do the top gasket or the bottom or both?
Any chance the rocker arm, or valve adjustment was messed with while in there?
That would explain the sudden loss of compression.
Did the injectors get removed or just the lines feeding them?
Were new seals used on the injector lines, or injectors if they were removed?
Anything done on reassembly like use parts cleaner?
Was any starting aid used?
When they did the valve cover, did they do the top gasket or the bottom or both?
Any chance the rocker arm, or valve adjustment was messed with while in there?
That would explain the sudden loss of compression.
Did the injectors get removed or just the lines feeding them?
Were new seals used on the injector lines, or injectors if they were removed?
Anything done on reassembly like use parts cleaner?
Was any starting aid used?
Both top and bottom valve cover gasket was replaced
The injectors were not removed
The only cleaner was used was to clean the valve cover
I don’t believe the rocker arms or anything right there got adjusted. Didn’t mess with none of that
No starting fluid was used
The injectors were not removed
The only cleaner was used was to clean the valve cover
I don’t believe the rocker arms or anything right there got adjusted. Didn’t mess with none of that
No starting fluid was used
When working as an engine mechanic for Toyota motor co. I ran across an engine (gasoline) with all cylinders that had IDENTICAL compression readings and ran horribly.
It turned out to be a head gasket that was eroded across multiple cylinders....so they all shared the same compression readings.
Any chance they messed with head-bolts/studs while they were in there?
It turned out to be a head gasket that was eroded across multiple cylinders....so they all shared the same compression readings.
Any chance they messed with head-bolts/studs while they were in there?