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1993 Chevrolet S10 2.8L v6
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Discussion Starter · #1 ·
Hey y'all! One of the fuel injector connectors on top of my carburetor is burnt and I think that may be causing problems with my very rough idle, terrible fuel economy, and hard start. Has anyone had any experience with something like this in the past and/or any tips to test/replace them without buying a new wiring harness? Thanks!
 

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98 2.2 Extended cab, 2001 V6 Extended cab Sport Suspension, 2001 V6 Extended Cab 4x4
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Go to your local auto part store and buy a new injector harness. You will have to cut and splice into your existing harness but it's not too hard. I prefer to solder the wires in this situation but crimps will work if you have a good crimp tool. I said good crimp tool not the ones that come in those packs hanging on pegs near the rest of the crimp connectors.

 

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1993 Chevrolet S10 2.8L v6
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Discussion Starter · #3 ·
Go to your local auto part store and buy a new injector harness. You will have to cut and splice into your existing harness but it's not too hard. I prefer to solder the wires in this situation but crimps will work if you have a good crimp tool. I said good crimp tool not the ones that come in those packs hanging on pegs near the rest of the crimp connectors.

I'll make sure to! I always solder and heat shrink when dealing with wiring just because it not only works better but looks better too. Do you think that the fuel injector connectors could cause these problems?
 

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98 2.2 Extended cab, 2001 V6 Extended cab Sport Suspension, 2001 V6 Extended Cab 4x4
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Oh how I hate the TBI engines! I would replace the connector if it is burnt no matter what. As for how well it runs, look at the injector's spray pattern, it should be a fine misty cone, not a wonky spray like a windex bottle spray. That being said, there are many things that can cause issues with the TBI engine to run like crap. First do you have any codes? 34 would really make it run like crap, that's the MAP sensor not being happy. In reality you would need to plug in a scanner and see what your live data says on the issue could be. I am working on one right now that has no codes but runs like crap. The LTFT show rich (pegged out at 138) and the O2 sensor shows lean. It has a bad misfire that causes my timing light to flutter outside the normal spark event. At this point I'm looking at low fuel pressure or a bad dizzy, or both.
 

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1993 Chevrolet S10 2.8L v6
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Discussion Starter · #5 ·
Oh how I hate the TBI engines! I would replace the connector if it is burnt no matter what. As for how well it runs, look at the injector's spray pattern, it should be a fine misty cone, not a wonky spray like a windex bottle spray. That being said, there are many things that can cause issues with the TBI engine to run like crap. First do you have any codes? 34 would really make it run like crap, that's the MAP sensor not being happy. In reality you would need to plug in a scanner and see what your live data says on the issue could be. I am working on one right now that has no codes but runs like crap. The LTFT show rich (pegged out at 138) and the O2 sensor shows lean. It has a bad misfire that causes my timing light to flutter outside the normal spark event. At this point I'm looking at low fuel pressure or a bad dizzy, or both.
I don't have an obd reader so I use the ol paperclip trick and have no codes other than the all clear, as for the spray pattern it does look misty on the outsides but does have a little windex stream looking portion in the middle. Could it also be the carb jets along with the injector connectors?

(Also I just wanna say thanks, when I had a previous problem with my truck about 2 months ago I also made a thread and you were one of the first to reply, thanks for being so responsive and helping people out.)
 

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98 2.2 Extended cab, 2001 V6 Extended cab Sport Suspension, 2001 V6 Extended Cab 4x4
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There is no carb jetting or anything like that with the TBI. It's a pretty simple system really but due to the primitive nature of the computer they are hard to work on. Metering is done via information from the MAP, Coolant temp, Throttle position and O2 sensor. There is also Tach data thrown in for fun... and timing!

If you are dripping or have an oddball center spray you have one of 3 problems. The first problem is the most expensive, which is the injector is done. A new injector (dont go remanned here) and a rebuild kit for the TB is about $150 all together. It is pretty easy to do, I just did one a couple weeks ago. Second the fuel pump is dying but not yet dead. Think of that old man that can still walk but takes 20 minutes to walk into the gas station to pay for fuel. He is still getting it done, just not very well. Or third, which kinda goes with #2 but could be a stand alone issue, is your fuel filter is clogged. It should be changed with your pump any way. Get a fuel pressure test set from your local auto part store's rental tools to test. TBI needs about 30-35 lbs to work properly if I remember right, but you may want to look up what it really is as my memory gets muddled from having to work on too many different rigs over the last 30 years.

So the odd spray pattern or drips can be from low pressure or bad injectors, and they will cause running issues. If you are ever in the market for a scanner that will do everything you need the Bosch OBD1300 (not a sponsor) will cover your truck and all OBD2 vehicles out there. It's what I use and I like it. Amazon has them for under $200 and it's worth the money to pick one up. Autel makes a similar unit, that I think runs the exact same software (the menus and screens look identical) but is a bit harder to locate. Usually the Autel comes from overseas, but costs a bit less. I would have to look up the model number if you are interested.
 

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1993 Chevrolet S10 2.8L v6
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Discussion Starter · #7 ·
There is no carb jetting or anything like that with the TBI. It's a pretty simple system really but due to the primitive nature of the computer they are hard to work on. Metering is done via information from the MAP, Coolant temp, Throttle position and O2 sensor. There is also Tach data thrown in for fun... and timing!

If you are dripping or have an oddball center spray you have one of 3 problems. The first problem is the most expensive, which is the injector is done. A new injector (dont go remanned here) and a rebuild kit for the TB is about $150 all together. It is pretty easy to do, I just did one a couple weeks ago. Second the fuel pump is dying but not yet dead. Think of that old man that can still walk but takes 20 minutes to walk into the gas station to pay for fuel. He is still getting it done, just not very well. Or third, which kinda goes with #2 but could be a stand alone issue, is your fuel filter is clogged. It should be changed with your pump any way. Get a fuel pressure test set from your local auto part store's rental tools to test. TBI needs about 30-35 lbs to work properly if I remember right, but you may want to look up what it really is as my memory gets muddled from having to work on too many different rigs over the last 30 years.

So the odd spray pattern or drips can be from low pressure or bad injectors, and they will cause running issues. If you are ever in the market for a scanner that will do everything you need the Bosch OBD1300 (not a sponsor) will cover your truck and all OBD2 vehicles out there. It's what I use and I like it. Amazon has them for under $200 and it's worth the money to pick one up. Autel makes a similar unit, that I think runs the exact same software (the menus and screens look identical) but is a bit harder to locate. Usually the Autel comes from overseas, but costs a bit less. I would have to look up the model number if you are interested.
Thanks for the help! I'll make sure to check out the injectors this weekend to see what needs to be done to them. As I'm a bit strapped for cash right now I don't think I'll be able to pick up an OBD scanner just yet, but when I do ill make sure to pick up the Bosch 1300.
 

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