'98 AWD - odd idle/running issues after engine out service

[V50M66]

So, finished up the engine out service on my '98 V70 AWD to replace rear main seal, steering rack, cam seals, radiator, Japanifold, and 16T upgrade. Everything seemed great, but now I'm running into some odd issues with running and idling. Take it for a drive, and it runs fine cold (and when driving normally when up to temp). Pulling into my driveway, the car starts idling weird, misfiring, and occasionally just shuts itself off completely.

Coolant temp live graph seems just fine. Doesn't have to be all the way up to temp to stumble it appears, but the coolant temp reading stays the same (within a degree C) when it stumbles. So that seems to rule that out.

Did live data of crank sensor and everything seemed fine - RPM tracked well, with no random dips.

Initially thought it was the MAF sensor, but it also seems that it also stumbles with the MAF unplugged. Tried cleaning it with that CRC MAF cleaner, but nothing changed.

Tried live data on the MAF and didn't see anything out of the ordinary.

No codes have shown up in the computer, aside from the two SAI codes (because I removed all the SAI stuff when I did the engine out service), as well as a MAF communication code from unplugging it. Any chance the SAI delete has anything to do with this?

Seems like it's more unhappy at idle. IAC maybe? Anyone have a good way to test them?

Any other ideas as to what this could be? Kind of at a loss

Pictures of the engine out service to give you something to look at:

IMG_5568.JPEG (373.31 KiB) Viewed 306 times

IMG_5546.JPEG (429.99 KiB) Viewed 306 times

[scot850]

Have you looked at fuel delivery? Fuel pump pressure and fuel pump relay may act up once they get warm.

Neil.

[V50M66]

After a bunch of diagnostic tests that all proved inconclusive at best, the car has started running perfectly with no hiccups. Nothing has been changed that would impact this, so I'm kind of confused. Apparently this kind of thing sometimes happens after extended battery disconnects or engine swaps, so I'm going to have someone daily drive it to make sure it's actually fixed before I take it out of AAA range.

[scot850]

You can get all sorts of weird issues. I have heard stories of the car not starting as it had lost the grounding from the engine to the trans after the engine or trans had been removed. Solution was adding a ground wire between the 2. Certainly a weird issue.

Glad that the issue resolved itself, but I understand your concern not knowing how/why it happened!

Neil

[abscate]

Seems like it's more unhappy at idle. IAC maybe? Anyone have a good way to test them?

Pull it off and clean thoroughly. Ignore the sneers and catcalls from the 1999- with sexy Italian model ETBs.

[V50M66]

Seems like it's more unhappy at idle. IAC maybe? Anyone have a good way to test them?

Pull it off and clean thoroughly. Ignore the sneers and catcalls from the 1999- with sexy Italian model ETBs.

Yep, did this. It was pretty nasty and sticky, and cleaned up nicely, but didn't seem to help.

But now I have codes - misfire on 1, 3, 5, and a new EVAP code. But it threw these after it started running fine again. Think I might be dealing with multiple problems at once