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Discussion Starter · #1 · (Edited)
Folks, as I was tightening up my new EGR valve on the 1990 GMC Suburban (with a 5.7L 350 engine) my wrench slipped, and I cracked a black plastic pipe leading to the fuel injector from some bracket behind the EGR valve. I couldn't figure out how it attached to the fuel injector, nor how it attached at the other end either, so I went out to AutoZone and purchased a small piece of hose, which I thought I could use to bridge the two broken pieces. As it turns out, the hose has just a smidgen too large ID, and it slipped over the pipe pretty easily. I put things back together, and within a few seconds the Check Engine light came on, so I shut it off.
Does anyone know what this black pipe does? It has an Outer Diameter of 1/4".
While messing things up, I also managed to break the little clip thingy that holds the wiring harness into the Injector housing. Let me explain; there is a tan colored plastic female piece coming out of the injector, and there is a wiring harness with 4 cylindrical tubes that plugs into the tan colored plastic female piece. On top of the tan colored receptacle was a little nub, that the wiring harness sort of clipped to. Now I can insert the wiring harness, and looks as though it holds pretty well, but I would like to make it a little more secure, as I'm sure that that is the wiring that controls the injectors.
Does anyone know if that tan colored receptacle removes from the throttle body easily? If not, any suggestions to making it more secure and snug?
I shut the hood and told my wife to not drive the car, and am hoping you all can give me some idea of what to do to fix this mess that I've caused.
Thanks so much in advance!:grrrrrr:
 

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Folks, as I was tightening up my new EGR valve on the 1990 GMC Suburban (with a 5.7L 350 engine) my wrench slipped, and I cracked a black plastic pipe leading to the fuel injector from some bracket behind the EGR valve. I couldn't figure out how it attached to the fuel injector, nor how it attached at the other end either, so I went out to AutoZone and purchased a small piece of hose, which I thought I could use to bridge the two broken pieces. As it turns out, the hose has just a smidgen too large ID, and it slipped over the pipe pretty easily. I put things back together, and within a few seconds the Check Engine light came on, so I shut it off.
Does anyone know what this black pipe does? It has an Outer Diameter of 1/4".
While messing things up, I also managed to break the little clip thingy that holds the wiring harness into the Injector housing. Let me explain; there is a tan colored plastic female piece coming out of the injector, and there is a wiring harness with 4 cylindrical tubes that plugs into the tan colored plastic female piece. On top of the tan colored receptacle was a little nub, that the wiring harness sort of clipped to. Now I can insert the wiring harness, and looks as though it holds pretty well, but I would like to make it a little more secure, as I'm sure that that is the wiring that controls the injectors.
Does anyone know if that tan colored receptacle removes from the throttle body easily? If not, any suggestions to making it more secure and snug?
I shut the hood and told my wife to not drive the car, and am hoping you all can give me some idea of what to do to fix this mess that I've caused.
Thanks so much in advance!:grrrrrr:
Put down the tools and step AWAY from the vehicle... :lol:
If I have this much trouble doing something to mine and nothing seems to go right, I just take it to the dealership and cut my losses.
 

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You said your check engine light was on, what was the code? If you don't know how to check it, find the ALDL connector below the dash and take a paper clip or a piece of wire and insert one end into terminals A and the other end into terminal B. Turn the key to the on position (don't start it) and watch the check engine light. It will flash some codes for you. It will start with code 12 (one blink, pause, two blinks). It will flash each code 3 times and then move on to the next code. It will start over at code 12 when it has gone thru the entire list of problem codes. Find out what the code is (or post it up here and someone can help decode it for you) and see if you can figure out what caused it.

Here is a diagram of the ALDL connector and it shows where terminals A and B are.

 
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Discussion Starter · #4 ·
Thanks so much, folks, for your replies and advice. I thought I'd share how I resolved these issues. First of all, the electrical plug to the fuel injector is not tan, but black. It looked tan last night by the fluorescent light, but as I worked on it tonight, it is definitely black.
I called the dealer today, and he had never heard of the black tue. I did look it up in my technical manual (real OEM engine manual) and found out that the black tube was the MAP vacuum tube which some how measures vacuum at the manifold and that is somehow fed into the computer The dealer told me that the part was available (only one in the entire city of Houston) but he couldn't tell me how it connected to the fuel injector, as he had no idea. I thanked him, but told him that if I don't know how to connect it, it would do me no good. By the time I got home from the office, I had concocted the idea to take some heat shrink tubing, place it around the broken joint in the tube, and shrink it with a heat gun. When I got to working on things, I remembered that I had a piece of hose that I always carried around in the back of my old 1983 Mercedes 300D, which might just fit over the broken tube.
Sure enough, I cut off ~2" of the plastic hose, fitted half of it onto one side of the broken tube, then inserted the other side into the other end of the plastic hose. A very tight fit! I fired up the car, and NO CHECK ENGINE LIGHT!:party:
About the electrical connection to the injectors - I looked at the connection today, and it fits into the Injectors very tightly, so I think I will leave well enough alone. I will definitely check both of these items periodically, but I think we're good to go now! Thanks so much again for the advice, and hopefully this will help some one in the future who happens to break that little black tube!
 
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