83 K5 Blazer LS swap issue

[iamtherealJayy]

So I swapped my 1983 Chevrolet K5 blazer with a 5.3/4L60e, working on it every other weekend it took longer than I wanted but I finally got around to the first start, and it runs poorly. I noticed the intake manifold had a broken nipple for a vacuum port so I swapped it with a spare I had. No change. I did have code po122, ecu was giving no voltage what so ever, no biggy swapped a spare ecu I had, still no better. Only other codes it shows is po200 and po650. I’m at a loss.

 

[Hunter79764]

I'd check your grounds for the ECM, there's a few of them, and with 3 sorta unrelated codes, that's where I'd start.

 

[consti2tion]

Are you running a factory modified harness or aftermarket harness?

 

[Camar068]

I'd check your grounds for the ECM, there's a few of them, and with 3 sorta unrelated codes, that's where I'd start.

@iamtherealJayy yup, disconnect the battery, then put your meter on ohms. Then put a lead on the negative battery cable, and test EVERY ground connector on the ECM connector. After that check all your wires to the throttle.

The p0650 is an issue with the bulb/indicator you have wired for the check engine light.....ignore that one....no biggie. Fix that later.

Post results and we'll go from there.