454 TBI Swap, idle issues, no voltage to check engine light

Please help!
I recently swapped in a 454 TBI from a 1992 GMC Suburban into my 86 GMC pickup. I was able to get the entire motor, wiring harness, and
computer from the donor Suburban. The motor starts, but has a high idle. I was hoping to pull the trouble codes from the computer, but there is no power to the check engine light. Even when the truck key in in the ACC position, all lights come on except the check engine light. I identified the pin at the computer which is the check engine light lead and there is no voltage at this point. I have never seen the check engine light come on in the truck and it is connected properly (I was able to get my hands on a engine electrical book from the local dealership). Why would the computer not be sending power to the check engine light?
Any help would be greatly appreciated as I am at my wits end with this project!!
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In article
snipped-for-privacy@gmail.com wrote:

The computer does not "send" power to the check engine light. Power to the check engine light comes from the 'gauges' fuse, same as all the other warning lights in the cluster. The computer switches the ground side of the check engine lamp when it is desired to be illuminated.
Study the wiring diagram again, you'll see where the ground side of the check engine light branches off to the ALDL, a useful place to start some diagnostics.

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aarcuda69062 wrote:

High idle likely would not show a code on an OBDI system.
However high idle on an EFI system is probably a disconnected or broken vacuum line. The extra air isn't metered and causes a high idle.
--
Steve W.

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The problem does not seem to be a vacuum leak, that was the first thing i checked. One bit of information that may help is that I removed the TBI and cleaned the entire unit with brake cleaner, replaced the gaskets and re-installed prior to having the idle issue...any ideas???
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wrote:

The problem does not seem to be a vacuum leak, that was the first thing i checked. One bit of information that may help is that I removed the TBI and cleaned the entire unit with brake cleaner, replaced the gaskets and re-installed prior to having the idle issue...any ideas???
If you remove that tbi and replace the PROPER gasket PROPERLY, your problem should be solved! Lemme know. sam
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snipped-for-privacy@gmail.com wrote:

Most brake cleaners are NOT plastic safe. There are a few chunks of plastic in there that may have been damaged.
Could also have damaged the gaskets depending on the cleaner.
--
Steve W.

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Using your advice, I hooked up a test light with the ground to the "check engine" pin at the computer and the positive to a general hot wire, nothing... :(
Anything I may be missing?
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In article
snipped-for-privacy@gmail.com wrote:

If you supply 12 volts to the same place two different ways, wouldn't that be the expected result?

Understanding how the circuit works.
The ECM switches the CE light to ground at pin A6 ECM pin A6 should be 12 volts if the ECM is -NOT- commanding the CE light on. The 12 volts is coming from the gauges fuse thru the CE bulb filament. Applying 12 volts to pin A6 accomplishes nothing other than applying 12 volts to the other side of the CE light bulb.
What happens if you jumper pin A6 to ground (KOEO) with a jumper wire? Does the CE light illuminate?
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