Soo... does this sound like I found my problem? If so its about ready to go back together
LB7: #1 injector shorted
- Thread starter RPierson51
- Start date
Soo... does this sound like I found my problem? If so its about ready to go back together
yeah so a week and a half ago i put it all back together with the new injector and it ran great.. until this morning, half way to work and all of a sudden same thing: loss of power sounded like a tractor, and 1,4,6,&7 are out again, i guess the original injector shorting wasnt just the injector, something must have caused it since it seemed like its happened again
I am having similar issues with my truck. I put some remanned injectors in her, but they sat on a shelf for a while after a friend pulled them (only had 20k on them) to go bigger. Mine started fuel knock then shut off with these codes. I wondered if the silnoids were grounding out of the actual injector is bad/sticking. Is there a way to tell or is it a common issue? Pierson, do you know the history of the injectors before you got the truck?
The injectors are dealer installed 4 years ago, besides the one I installed last week that was a reman, I un plugged the injector harnesses and ohmed each injector out seperately and they all ohm out like. 4-.6 ohms so Im hoping it isn't another injector although its running the same codes
I know the thread has been dead for a minute, but I wanted to give you an update. I took the chance and just replaced my injector solenoids and she runs great now. When I tested the resistance from one 'nipple' of the solenoid to the other they all read good, but I decided to chance it anyways. I think they must have gone bad just sitting for a year or so. Hope this helps someone in the future.
this thread is not dead, my truck still is.
i didnt know the solenoid itself can be replaced without replacing the whole injector i woulda just done that when i replaced #1 inj. oh well, i tested all mine again and they all test good how could the solenoids be bad then? how long/miles has it been since you did this and your trucks running good? where did you get the solenoids? This thread is not dead i check it often as my issue is not resolved and i need my truck fixed badly
i didnt know the solenoid itself can be replaced without replacing the whole injector i woulda just done that when i replaced #1 inj. oh well, i tested all mine again and they all test good how could the solenoids be bad then? how long/miles has it been since you did this and your trucks running good? where did you get the solenoids? This thread is not dead i check it often as my issue is not resolved and i need my truck fixed badly
First things first did you go through the harness and check it out well for rubs that would cause a short?
I had three solenoids short out on me over the time i had my LB7
First one I ended up replacing it with a new one for the dealership
2nd, and 3rd, I ended up purchasing a few used injectors on ebay and just swapped the coils out leaving the injector body in place.
I made a special socket for the solenoids being that they are somewhere around an 18 sided nut. Took a 1" emt and heated red and tapped it onto a bad injector solenoid so as to form it to the shape
All three shorted to ground and I believe two of them where #5 or #7. Dont remember but it was the same one twice
Just like any injector swap, you need to be meticulously clean and make sure you dont reassemble the high pressure lines if anything is in the injector fuel input conector.
I have no idea why they shorted out
First one I ended up replacing it with a new one for the dealership
2nd, and 3rd, I ended up purchasing a few used injectors on ebay and just swapped the coils out leaving the injector body in place.
I made a special socket for the solenoids being that they are somewhere around an 18 sided nut. Took a 1" emt and heated red and tapped it onto a bad injector solenoid so as to form it to the shape
All three shorted to ground and I believe two of them where #5 or #7. Dont remember but it was the same one twice
Just like any injector swap, you need to be meticulously clean and make sure you dont reassemble the high pressure lines if anything is in the injector fuel input conector.
I have no idea why they shorted out
How did you determine which injector was grounding? I have my passenger side valve cover open (dreading removing the driver side) and when measuring the continuity of the injectors they read...
#1 = .06
#3 = .00
#5 = .00
#7 = .00
I don't think .06 is a bad reading do you? Or is this a sign my #1 injector may be grounded?
Checking continuity doesn't tell you anything. A short is a wire rubbed through to ground or to another wire. You need to visually inspect the harness for this.
I got burned by this on my wifes old car. Threw an injector at it cuz the wires tested fine. It had a rubbed through wire that was intermittently shorting that was the actual problem though.
If I use my ohm meter between the ground and a single wire and it reads 1.00 then that means there's NOT a short to ground but if it reads anything else like .77 or .90 then that means there IS a short to ground. Isn't that correct? And the smaller the number like .25 means it's a stronger contact.
Right?
I disconnected the connection right at the valve covers for the injectors and measured there. There are four pins. It should be obvious but two go to one injector and the other two go to another injector. I measured the resistance from one of the pins to ground and it read continuity. The others did not.
After pulling the valve covers. I took the wires off the injector and measured there. It read to ground so I knew it was a bad injector.
Then I disconnected the fcim from the harness and measured the resistance to ground while moving the harness around. Everything checked out good
When it happened again, except this time on the passenger side, I did the same test but also opened up the harness to see if there was anything I could find that would cause it. Everything checked out good and no chafes or exposed wires.
Thats when I made the socket. I just replaced the coil as I had no clue what condition the bodies where in being that I got them on eBay for about $75 each.
I used break clean and a vacuum pump to make sure all of the ports on the injectors where spotless before reassembling it.
At one point before the injectors showed up, I dont recommend it but I needed my truck to get to work as it was my only vehicle at the time, I connected a small inductor in place of the bad injector to trick the FCIM into thinking everything was ok and drove it for about two weeks with one cylinder out. This was to keep it out of limp mode and get the other injectors back on so it had enough power to safely drive down the road
After pulling the valve covers. I took the wires off the injector and measured there. It read to ground so I knew it was a bad injector.
Then I disconnected the fcim from the harness and measured the resistance to ground while moving the harness around. Everything checked out good
When it happened again, except this time on the passenger side, I did the same test but also opened up the harness to see if there was anything I could find that would cause it. Everything checked out good and no chafes or exposed wires.
Thats when I made the socket. I just replaced the coil as I had no clue what condition the bodies where in being that I got them on eBay for about $75 each.
I used break clean and a vacuum pump to make sure all of the ports on the injectors where spotless before reassembling it.
At one point before the injectors showed up, I dont recommend it but I needed my truck to get to work as it was my only vehicle at the time, I connected a small inductor in place of the bad injector to trick the FCIM into thinking everything was ok and drove it for about two weeks with one cylinder out. This was to keep it out of limp mode and get the other injectors back on so it had enough power to safely drive down the road
If you are using an old school sweeping arm ohmeter I suggest stepping up your game and getting a more accurate and easier to read digital multimeter.
Not sure what kind of meter your using but most digital meters read OL when measuring a wire that is supposed to be isolated from the ground side when measuring between it and the ground. Any other number means it is making contact with the ground. If checking the wire itself you should see 0. Numbers higher than that means it possibly has poor continuity for a variety of possible reasons including In-Line resistors, breaks, shorts and poor connections.
I am so lost on this issue. Here's what I've done over the last couple days.
I pulled off the entire bale connector harness, brought it inside, took off every bit of electrical tape, inspected every wire, checked every connection with my digital multimeter, looked at every pin, there is nothing wrong with the harness. I put new tape and protective sleeves on it. I can say with certainty it is not the harness.
I pulled my driver's side valve cover off and checked the continuity of each injector, all read .00 and I also checked each stud on all injectors for continuity to ground, none are reading grounded. All 7mm captured nuts were tight.
I'm quite nervous about needing new injectors because my lower valve cover bolts are so incredibly tight that I don't think I can get them off without stripping. But maybe that's not an issue right now because I am not getting the sign that I need new injectors.
HELP!
Could it be that I need a new FICM? I was thinking if I got one from a salvage yard with a return policy then I could switch it out to see if that's the problem then return it if not.
I pulled off the entire bale connector harness, brought it inside, took off every bit of electrical tape, inspected every wire, checked every connection with my digital multimeter, looked at every pin, there is nothing wrong with the harness. I put new tape and protective sleeves on it. I can say with certainty it is not the harness.
I pulled my driver's side valve cover off and checked the continuity of each injector, all read .00 and I also checked each stud on all injectors for continuity to ground, none are reading grounded. All 7mm captured nuts were tight.
I'm quite nervous about needing new injectors because my lower valve cover bolts are so incredibly tight that I don't think I can get them off without stripping. But maybe that's not an issue right now because I am not getting the sign that I need new injectors.
HELP!
Could it be that I need a new FICM? I was thinking if I got one from a salvage yard with a return policy then I could switch it out to see if that's the problem then return it if not.