TBI 454 to TBI 350 head scratcher code 43

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someotherguy

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Not if you buy from the parts stores, at least for the ICMs. That's why I'm curious what's in there.
Wasn't talking about ICM's, was talking about knock sensors. We have no information on what application the 350 engine came from. OP's 1993 1 ton would have a 4L80E or an NV4500; the 350 could have come from a truck with either of those, OR an NV3500, 4L60E. So he's got a 50/50 chance of having the correct knock sensor as the transmission type dictates the sensor part # and even the application notes get a little sketchy.

OP - Ohm reading isn't a good indicator as you would expect them to ohm out the same if good. Good doesn't mean correct part # though.

Richard
 

Adam Courtney

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Wasn't talking about ICM's, was talking about knock sensors. We have no information on what application the 350 engine came from. OP's 1993 1 ton would have a 4L80E or an NV4500; the 350 could have come from a truck with either of those, OR an NV3500, 4L60E. So he's got a 50/50 chance of having the correct knock sensor as the transmission type dictates the sensor part # and even the application notes get a little sketchy.

OP - Ohm reading isn't a good indicator as you would expect them to ohm out the same if good. Good doesn't mean correct part # though.

Richard
What application should I be getting a knock sensor for? The 93 is a 5-speed manual NV 4500 truck. As for what the 350 donor engine is, I have no way to know. The ECM in the truck currently is a 01227747.

As I said before, I pulled the same part number ECM out of my 88, it runs and drives exactly the same as the one I have currently with the same trouble code. I disconnected the blue wire from the knock sensor and the electronic spark control module and tested its resistance which was minimal. Meaning that wire is good. Also check the brown wire at the electronic control module had good ground and good 12 volt power with the key on with the red wire on the module. I think my hang up is between the escm and the ECM. If I knew where to pin in the yellow wire coming off the ESCM, I would run a wire directly from there to the ECM wherever it needs to go
 

Schurkey

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I don't know about earlier model years (TBI), but my '97 Vortec 7.4 uses TWO knock sensors.

If your ECM is expecting signal from two sensors, but there's only one installed, that could be generating a code.
 

PlayingWithTBI

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The Vin K (5.7L) 7747 uses 1 Knock Sensor located near the starter. Here's a wiring diagram from an 88. Edit: pin B7 on the ECM connector is where your yellow wire goes.

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PlayingWithTBI

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Here's your wiring connectors. "B" is in connector "C2" - lower left, HTH

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