Gen4 ls3 swap falls on its face while accelerating

[Eddtheman]

Just got my swap kinda driving.

this is an ebay engine(2010 GS ls3) that supposedly has a cam. I can see that it has dual valve springs and pushrods that are 7.35"s, no idea what lifters. I know it needs a tune but I still need to break in the clutch and figure out a few things. I had to raise the idle or else it would missfire at idle. It stumbles and falls on its face while accelerating.

Also for some reason once the oil temp reaches 100f it will start reading -4f for some reason.

Im very new to hptuners and not sure what to be looking at in the logs, I'll attach a log and was hoping you guys could let me know if there is something glaringlee obvious i'm missing.

Thanks.


edit: attached the tune as well, It is a brand new ecu

[gtstorey]

and the tune.

[LS ROB]

Post your tune as well so some of the more experienced guys can have a look. Looks like alot of weird happenings going on. bouncing in and out of closed loop - knock- trims showing rich, but o2 voltage don't match what the trims say.

[Eddtheman]

alright I attached the tune as well. It is a brand new ecu I just upped the idle so it wouldnt miss and stumble as much at idle. I have heard some people need to do a crank relearn. Do you think that could be a possibility?

[Alvin]

Since this is a swap.> Have you checked fuel pressure while it feels like it's falling on it's face?

[edcmat-l1]

alright I attached the tune as well. It is a brand new ecu I just upped the idle so it wouldnt miss and stumble as much at idle. I have heard some people need to do a crank relearn. Do you think that could be a possibility?

Crank relearn has nothing to do with it running rough.

[Eddtheman]

Just went out and tested this by placing my phone camera watching the fuel gauge. When falling on it's face it bounces from 57ish to 50.

https://jmp.sh/s/NqQS4KufxAlyVjwRKsLD

[Alvin]

that doesn't look great to be honest. I'd continue to watch it... especially under a heavier load.

It sounds like you got a miss other than that.. have you done the simple things? Wires/ plugs.. if you do a log with a wide open throttle pull I could narrow down which side it might be on.

[Eddtheman]

Most that have done the swap say the fueling is fine for the stock 376 although my fuel pump has 187k miles if it has never been changed(i'm the 3rd owner) But since this has a cam and such I might need to upgrade the fuel line.

I tested the resistance on the wires, all read 840 besides one reading 700. It had ngk tr7ix gapped to .028 when I got the engine. I put in some ngk tr5ix at .040 and didn't notice a difference. The engine has 44k miles. Ill try and get a WOT pull tonight or tomorrow. It also bucks sometimes when not falling face first so I'll see what I can do.

[Eddtheman]

alright did a WOT. it didn't really accelerate at all. here is the log.wot51624.hpl

[Alvin]

Something is wrong with the map sensor. It's reading about a 1/4 of what it should. The tune file is setup for a stock map sensor. Is that what you have?

It should read near 100kpa with the key on engine off

[edcmat-l1]

Wow that thing makes ALOT of vacuum LOL

[Eddtheman]

Just took a look at the part number. Ac Delco 12592525. Comes up as a supercharger map sensor. Not sure why the prev owner would have used that one.

[Alvin]

Change the map sensor values to 312.5 -11.25

[edcmat-l1]

Red label LSA/LS9

[Eddtheman]

Alright I changed the linear and offset characteristics to the values you suggested but it's still doing the same thing. Are there any other values that need to be changed?

[Alvin]

that doesn't look great to be honest. I'd continue to watch it... especially under a heavier load.

It sounds like you got a miss other than that.. have you done the simple things? Wires/ plugs.. if you do a log with a wide open throttle pull I could narrow down which side it might be on.

[Eddtheman]

I redid it as write entire instead of calibration but now it won't start at all. It's reading 85 kpa with just key on. In utah I'm at about 4400ft elevation.

It previously being boosted might explain the tr7ix gapped to .028.

I'm going to pull an injector and see if it's stock or not.

[edcmat-l1]

Kpa sounds about right for your elevation. If someone previously tuned it for the MAP being off, you'll have to undo what they did.

[Eddtheman]

It is currently just the stock tune they sent me when I ordered the ecu, besides the current changes to the idle and now map sensor