Looking for TBI Expert Input

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Kilian

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Wisconsin
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K
Truck Year
1983
Truck Model
C2500 hopefully converting to K2500
Engine Size
350
Got an 87 350 TBI that I want to get running to use around the farm while working on my 83 project. I know little about TBI systems, so looking for some help with the current situation:

- Engine starts but idles rough.
- Runs better at faster speeds
- No check engine light
- New spark plugs (PO sent them along so I installed them)
- Both injectors seem to be spraying gas, engine smooths out a little when disconnecting one side or another.

Have a friend that has a scanner for seeing if there are any codes, not sure if all would trigger the check engine light.

Thoughts? I know it's not a lot of info but looking for some basic TBI things to look into. Thanks.
 

1985c20

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Torrington, CT
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Chuck
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1985
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C20
Engine Size
350
See if your buddy’s scanner can pull live data and check what the reported coolant temp is. My first guess would be your coolant temp sensor is bad showing a really cold value so your computer is dumping fuel to compensate. That’s why it runs a little better when you disconnect one fuel injector. TBI are pretty simple, it’s usually the coolant temp sensor, fuel pressure, or ignition when they stop running right.
 

gmbellew

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glen
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suburban 1500
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check the drivability and emissions manual in the reference library. it has a while section on things like this. I also like aldldroid and a Bluetooth OBD1 reader to see live data and help diagnose of your friends scanner can not see live data.
 

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