Won’t idle after rebuild

Hey there,
I bought a 1999 GT roller. I have since put in an engine and trans. The engine is a non-PI block with trick flow heads and trick flow cams. The intake manifold is all stock with stock injectors.

I can’t get it to idle right now. It starts but then just falls and dies. The only way I can get it to idle even a little bit is to unplug the Maf.

I pulled the log and it looks like the short term fuel trims are at 42% on both banks. I assume that the engine is flooding and that’s why it won’t idle.

My question is what causes the short term fuel trim’s to be that high. I have long tube headers, and the O2 sensors appear to be reading lean. I don’t see how they could be lean with all that fuel in there.

I’m about to start ripping apart the top part and takeoff the intake manifold and check everything there but I would appreciate any ideas.

I had 24 pound injectors in before putting the stock back in. I did get a tune from Bama Performance but that tune was for the 24 pound injectors. Could this all just be because of the tune?

I just went back to a stock tune and it does the same thing. I can only get it to somewhat idle with the Maf unplugged.

Thanks so much.

I am an idiot. I put two gaskets on the intake manifold by mistake. I used a flat gasket for the trick flow heads, as well as putting on the stock style dorman intake manifold, which has gaskets on the runners. So I’m sure that that’s my issue.

Shuttleman83 said:

How much was your "roller"?

Click to expand...

I spent $1000. It came with a built tear end and a maximum Motorsport a k member kit.

Apparently it was a turbo race car before it was parted out. It only has 61k miles on it.

Shuttleman83 said:

Was it wrecked?

Click to expand...

Nope. It was stolen in 2015 but recovered.