3400 not running right.

[siKKa]

hey guys, i did a 3400 swap to my 1994 Z24 this past winter, it idled fine in the shop after the swap, i ripped it for the first time today it was good, its fast, but its not running right. at low RPM under load it misses and bogs and hesitates, i got a code 45 (too rich) and swapped out the ECM with one my cuzin gave me, it came from a 93 vert 3400, apparently, it was tuned for the multec1 and heated o2 (im not running a heated o2) i went for another rip and it was a bit better, but still doing the same thing. i cleaned and re gapped the plugs, i've narrowed this down to fuel (im pretty sure) i cant for life of me remember what fuel rail i used. but its the same one i ran when i had the engine in my corsica and it ran perfect... i cant see the fuel lines being reversed, big to big, small to small. after idleing with the 2nd ecm for about 10 min, it throws code 45 again (too rich) anyone else have any ideas?

[3400-95-Modified]

What injectors are you running and what is the ECM setup for?

[siKKa]

stated in the post. Multec1 and multec1.

[SappySE107]

What injectors are you running, 3400 or 3.1? What is the computer tuned for, 3.1 or 3400? Both can be multec 1.

[3400-95-Modified]

Yeah I was referring to flow numbers and then the flow setting in the ECM... As Ben stated that can differ a good amount, 19lb/hr 3400 injectors came in multec 1 form.

[1988GTU]

You see if the o2 is responding correctly in the scanner? Might have a bad coil.

[siKKa]

yep yep o2 is brand new. injectors are 3400 multec1... i was talking to my cousin tonight and he thinks he may have given me the wrong ecm... im just going to order sappeySE107s chip. im pretty sure its a tune issue, i didnt touch a thing, i pulled it out of my corsica, changed the timing cover and mounts and dropped it right into the cav... the engine moved 3 feet lol... and like i said, it ran flawlessly in the corsica... so, my money is on the tune.