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Discussion Starter #1
OK. Before anybody gets their feathers ruffled, the ice pick tech tip probably has it's use when you're out in the boonies and are trying to get home with only limited tools and no scanner for diagnosis. Kind of in league with WD-40 and duct tape. That said, let me share my findings before someone else spends more money on the same discovery. Knowing a fair amount about a variety of automotive and motorcycle electrical connectors, I was curious to see just what is being done to the female terminal of the injector harness connector by shoving an ice pick through it. So, rather than using my truck as a test rat, I bought four connectors from RockAuto.com. Chevy wanted $70 each, Rock Auto wanted $20 ( I never buy just one). Anyway, looking INTO the wiring harness connector, there are ports above and below the two large slots that receive the blade terminals of the injector. The small ports are to release the terminals from the plastic body of the connector. I inserted a very small pair of tweezers (hospital type) into the ports of each terminal and gently withdrew it from the connector body by pulling the wire. Voila!! The terminal has a lock tab on the top and bottom of the female terminal that "click" when inserted. So, if you jam an ice pick through the connector, as directed, you effectively mangle the female box terminal and likely could never remove it from the plastic connector body. I serviced mine with a small copper brush, CRC electrical spray and dielectric grease for the seals WITHOUT REMOVING THE FEMALE TERMINAL. A Q-Tip and some CRC worked to clean the injector cavity terminals. If you are getting injector "rattle", but do not get codes P0201 through P0208, the injectors are providing continuity and load verification to satisfy the computer. This doesn't mean they're discharging fuel properly, as was the case with my engine, and could only be pinpointed with the Tech2 scanner. If you want to see what an electrically failed injector does to engine operation, carefully disconnect #7 as it is the easiest to get to. Your engine will barely run with no power and lots of smoke if you increase throttle, because it's only running on one bank. You will get codes P0207 and P2146, which will lock in and have to be cleared. I read lots of forums looking for a simple cheap cure, but I just wasted two days. Chevy scanned it through the OBDII port for $100, found #8 cylinder missing and the fuel balance way off the mark. Replaced #8 injector and problem solved. In closing, I only posted this to save someone else a big expense and from wasting time. The axiom is, "We learn from bad experiences, other people's, if we're smart."
 

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In early 2007 I became aware that the LLY had a mysterious, unexplained problem where it would barely run. I was a few months away from driving to Alaska, which included places where you are a 100 miles from anything, and another vehicle is sometimes rare. By then I had learned of other LLY potential problems, all of which you could head off (harness over FICM/alternator bracket, large CAT fuel filter / Nicktane, etc.). But then people reported getting stranded in Baja or down a forest road . . . not good.

The only solution was to find a dealer and a new wiring harness. #2/#7 were notorious and GM provided a kit to splice new connectors. Neither of these sounded too good or easy to do . . . in Baja, a forest road, British Columbia, Alaska, or most places.

I was VERY concerned. Then came the Ice Pick method and an explanation that the injector connectors had a problem. I bought a scanner and got a sharp pointy tool. R-E-L-I-E-F ! ! ! I could sleep at night. I could drive with confidence.

I've never had to mess with my injector connectors. I've always suspected (1) a poor design that allows the connection to become loose and (2) corrosion. Since I live in Southern California (not right on the coast), it's usually dry, we don't have snow and salt, and things just don't corrode. My truck is over 7 years old and the underbelly is almost completely rust-free (just a little surface rust on some parts GM didn't paint or coat).

I think everyone should welcome your investigation and findings. Thank you for sharing ! ! ! If I understood what you are suggesting, an alternative is to simply clean the connector for a better connection, and apply dielectric grease to prevent corrosion. Sounds good.

I'm still suspicious that the connector could become loose from age/vibration and still needs to be tightened. Besides piercing with the ice pick, I've heard of others who "tightened" the connection by (1) using pliers or vise-grips to slightly squish the connector, or (2) shoving a small piece of aluminum foil in the connector.

Thanks again ! ! And thanks to those to came up with the Ice Pick solution ! ! !
 

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Discussion Starter #3
jake111 - Glad the pick trick worked for you, but unless I'm totally wrong you'll play Hell getting the metal female box terminal out of the plastic injector connector body as it is intended to be released. I held back a bit of info because my last epistle was getting a bit lengthly and I was afraid of putting people to sleep, drowning in details. However, to clean and tighten the female box connector I also used a slightly modified dentist's pick like is used to scrape placque from teeth. The tip was broken off so I just shortened it leaving about 1/16" of a hook and angle sharpened the sides. Kind of looks like a linoleum knife blade, but blunt. Put this about halfway into the release ports and rotated it until I could see the terminal contacts move toward the blade slot. Then used it to scrape the contact areas of the female terminal through the blade slot. A last blast of CRC, a little dielectric grease on the silicone gasket, and it snapped back into the injector cavity with a little resistance (a good thing). If you ever need to replace a connector with a repair pigtail, go online to RockAuto.com. The GM/Delco part number is PT2183. One is a "genuine GM part" and the other is a generic. Buy the generic. The wire leads are about 4" long and should be sufficient to take any strain off a too-short harness lead, which was a listed GM bulletin issue (#2 & #7 injectors). Still have to find the female box terminals without leads. Hate splices, but there's times you have to. I grew up in the desert of So. Cal., so I know all about sand intrusion and off-roading Vs ocean and seawater. Moved back to the Northwest, but on the arid side toward Idaho, so not much rain. Really didn't want to buy a diesel, but my restored 1973 F250 just didn't end up with the required torque to tow our trailer. That's all for now. Sorry there's no good way to give a Reader's Digest version of this issue without leaving a lot to intuit.
 

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Great info thanks.....
 

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Dirtymax, could you provide some photos of your research?
 

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where did you get the little brush, and what size did you use ?

thanks!
 

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Discussion Starter #7
Diesel Wanna Be and DRCook - To save space I'll address you both. The small copper brush was my dad's and I have absolutely no idea where he got it. Go to your local gun repair shop and see what they have. It should look like a pencil with a straight bristle brush where the eraser would normally be. Another source might be an office machine service store that maintains copiers and typewriters. Otherwise, just get an acid flux brush that's used for soldering. Harbor Freight and your local nut-and-bolt store should have them. Really, unless the connector has water trapped in it, they don't get all that cruddy. The CRC electrical component spray does most of the work. And always make sure it doesn't attack the plastic by testing it on the connector body with a saturated Q-Tip FIRST. Take the silicone gasket off so you don't lose it, BEFORE cleaning. CRC also makes the dielectric grease in a can like Cheez-whiz. You can find both at Schuck's Auto.

As far as photos, I don't have a camera that has real good resolution in macro mode for shooting close-ups. Also, I'm trying to get the part number of just the female box terminals, so a repair can be made without splices or having to buy the whole connector assembly. If I can take a good set of photos, I'll post them on the forum. Don't hold your breath, this might take a while.
 

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Ah, I thought you used one of the little tiny twisted wire "tube brushes" to actually get inside the connector and brush off the interior of the female connector components. They make them very small BUT want to sell them by the box, usually in the $80.00'ish range.

Never heard of Schuck's Auto. Is that a chain out where you live ?
 

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Discussion Starter #9
DRCook - It is an old chain that started in the Seattle area, but has been bought out by O'Reilly Auto Parts. It's part of Kragen and a couple of others. Anyway, I think the CRC products can be had at Walmart too. You might even try NAPA. A rifle bore brush wouldn't be small enough to get into the connector openings unless it was reeeeeally tiny. Like I said earlier, these are Weather pack type connectors with silicone seals where the wires come out and where they mate with the injector cavity. The main idea is to get them very clean and dry, lightly lube the seals and the bore of the injector cavity, and make sure they fit snugly with an audible click. The best thing you can do from there is leave them alone unless it's absolutely necessary to remove them. Don't leave an unplugged connector unprotected. Ziplock snack-size bags and some tape work great. I probably sound like a fanatic, but you can't imagine how many hours of cleaning could have been saved with a little preventive care. My big pet pisser is guys who disconnect A/C systems and don't plug or cap the lines. Then they have the guts to get pissy when they have to replace the silica gel receiver. Oh, well I've beat this to death. Just be thorough and you'll do fine.
 

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jake111 - Glad the pick trick worked for you . . .
Oh, I haven't used the pick trick yet, I just carry one in the truck.
. . . . The best thing you can do from there is leave them alone unless it's absolutely necessary to remove them. . . .
Absolutely!! That's why I've just carried the pick so far. Actually, I would be more likely to shove a small piece of aluminum foil up there as a first road-side attempt.

It's good to hear about a way to finesse it. But depending on the situation, a big hammer (I mean a pick) might come in handy.
 

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NAPA carries the cleaner. I had already purchased some. The brushes that I thought you meant are tiny. Like I said, I thought you were saying you used a tube brush to clean the terminals. One company has them as tiny as .032 brush dia, .022 stem dia.

I need to pull mine and clean and reseat them, just to make sure. I am going to make a brush using a fine needle and some thread. It will need to be small enough to not expand the connector. Spray and gently swab it out.

I kept one of the ends when I installed the nbr 2 and 7 wire harness so I can use it as a model to work with.
 

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Discussion Starter #12
Gents. I think this should be my last post on the subject and I'll just let whomever finds merit in it run with the ball. As in the first part of the message, the part number for the connector repair pigtail is PT2183 (88988963). Both numbers hail to AC Delco, but I recommend buying this part through RockAuto.com. The generic type is about $19.50. If you don't want to splice this onto your wiring harness, the metal crimp-on terminals can be had from most Chevy/GMC dealers for about $2.00. They're actually made by Bosch, but supplied by Kent-Moore Tools specifically for the technician. The part number is 1928498059 and are found in Tray 24. The tray is generally labeled as Delphi, but it has other types. Generally, they can only buy/sell them by the package of 20, but you might get the parts guy to sell just a couple. BE CAREFUL EXTRACTING THEM FROM THE CONNECTOR BODY. There's actually a special tool and the shop should have one in the same tray as the terminal. Once you get one out, it's obvious what an ice pick would do to it. You'll need a new silicone seal for each terminal too. The GM part number is 15324976 (same in Delphi). They're white and slightly smaller than for other connectors. If you have the proper crimping tool, great. If not, find one that does the terminal AND the seal. Be sure to lube the seal when you insert it back into the body and listen for it to click. OK, this should be sufficient belaboring of the subject. Hope this helps someone. Remember to use TLC when working with electrical connectors, and "clean is keen."
 

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Awesome info, thanks!
 

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Thanks Dirty. The Ice pick trick got me home, now to make sure she is good all the way around and the new clips will get zip tied this time.
 

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Discussion Starter #15
Fire05 - I wouldn't recommend the zip ties, only because something HAS to give if the wiring gets reeeeally pulled hard. The thumb releases are very positive and should be sufficient, providing they're not broken off. The three key elements to wiring systems I abide are 1) sufficient slack to allow normal movement of the device, but not to excess, 2) clean, undamaged terminations/connectors, and 3) lubricated sealing devices that allow proper engagement of mating components. Remember, with few exceptions, the first step in the trouble shooting section of most manuals will instruct the technician to check all terminations for a solid connection and will give coductivity values to qualify a range of acceptability. In avionics, this was paramount and the gospel. I think the info supplied through this message will solve the issue. It's also less expensive than simply replacing parts until the problem goes away.
 

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I have found that when pulling terminals, instead of trying to squeeze them to release, that if you look very carefully at how they are designed, you can slip a miniature flat blade screwdriver in, and GENTLY pop the locking part loose.

Once I caught onto this, I have them off in seconds. You slide the screw driver straight in (opposite from the direction they are plugged into the connector) and it will pop them loose. Don't try and do it from the side.

As I am almost at the point of putting the truck up for the winter, cleaning, putting dialectric grease and checking the entire harness out will be a spring time project. I quit driving my truck in the salt, as where I live in NE Ohio, they use so much of it, it eats vehicles up and it is a constant battle to stop corrosion damage.
 

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Discussion Starter #17
DRCook - Good plan for the Winter months. One last comment about releasing the terminals from the connector plastic body....really, no foolin', last one. The miniature screwdriver thing is ok if there's only one release tab on the terminal. In the case of the injector terms, there's two (read previous replies). You need to insert the equivalent of two miniature screwdrivers, simultaneously, into the openings at the 12 and 6 o'clock positions of each terminal to get them to release properly. I altered a pair of small tweezers to do this by blunting the ends and thinning the ends to eliminate the standard taper on the sides and lengthwise. Had to go reeeally slow with a fine grit grinding stone to keep the heat from affecting the taper. I plan to look for a set of the service tools to keep on hand. I look at it like carrying a spare and a jack. The first time you leave them home, you'll find that one, lonely nail in the road. All that said, I'm now off to work on the turbo vane position sensor issue. This one is being a bit of a pain, since the lovely folks at Honeywell who bought Garrett Turbos won't let me talk to an engineer who ACTUALLY knows how the sensor works and how to perform a linearity test of it's output. If you're interested, this issue might shed some light on why the guys at Chevy/GMC are generally clueless as to the turbo's modulation control and totally rely on the computer to diagnose problems. To be continued....
 

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I am not talking about releasing the internal terminals, just the plastic one that goes into the injector connection. Without taking too much apart to be able to pull them off the injector, it is easier to release the catch with a little screwdriver and pull the connector out. It was a pain hanging over the truck fenders and trying to get enough leverage to squeeze and pull at the same time. Lifting that tab lets the connector/terminal body be so easily removed without putting lateral stresses on it from trying to squeeze and pull at the same time.

I am going to simply clean mine out by getting a really thin needle and running some thread through the eye, to create a miniature brush as you will. Then using the electrical cleaner, I intend to flush out the connector, give it a few swabs with the needle/brush, blow it out with air, put the soft rubber seal back into the body and reassemble the connector and see how it goes after inspecting the remainder of the harness.

If that doesn't take care of the issue, then on to plan B.
 

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Discussion Starter #19
DRCook - Just a reminder...don't forget the dielectric grease!!! It's basically the same as Dow Corning 111 or Permatex spark plug boot release grease. CRC makes it in a can like cheese whiz. A little dab on a Q-tip works wonders. Tolerates temperatures up to +500 degrees and down to -40 degrees. Resists mild acids, caustics and puts a protective film on the silicone seals SO THEY DON'T TEAR. Good luck.
 

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Hi all. I'm have an 2005 2500hd lly 4x4 the truck has 129.456k and I just had the mysterious connector issue. I was driving down the road on my way to work and boom check engine light and instant limp mode. The truck sounded like a backhoe or a kabota 4 cylinder. Anyways when i got the truck home being a diesel tech I knew the trucks potential problems before I bought it. I plug my scanner in and just as I had expected a dtc of p0207 injector circuit malfunction cylinder #7. Well so the first thing I did was the ice pick trick. Because I didn't have the part (dealer only) so it worked. It last three days, luckily I'd gotten the part the next day through a hook up at a dealership. 60 buck couldn't pass it up, well before I could get the new pigtail 90 degree connector on it limped three separate time on me before I got to my shop. The ice pick trick is a emergency temporary fix to get you home or to a shop. I see this problem all the time. But it's scary if you don't know what the issue is. If you can fix the problem before it happens do it.
 
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