Engine backfiring?

[Slinky]

ok ive done the following mods and just stated the 95' z26 and it seems to be backfiring alot,
I realize there is VERY LITTLE back pressure, ive done an obd2 swap but havent tuned yet,
is it just because it needs a tune?
I let it idle for about 5mins and shut it off because the backfiring seemed to get worse, should i let it idle longer?

-3400 Block
-3500 Ported and Polished Upper Intake
-3500 Ported and Polished Lower Intake
-3500 Ported and Polished Heads
-Phenolic 3/8" Plenum Spacers
-L36 Injectors
-LX5 65mm Throttle Body
-Motor Oil/Trans Oil Cooler
-Cold Air Intake
-180* T-Stat
-Equal Length V6 Headers
-FULL 2.5" Exhaust
-High Flow Cat
-Magnaflow XLTurbo Dual Tip Stainless Muffler
-8.2mm Taylor ThunderVolt Wires
-160amp High Output Alternator
-6061 Aluminum Overdrive Alternator Pulley
-4 Awg BIG 3 Rewire
-NGK Iridium Plugs
-EGR Delete
-ABS Delete

[Slinky]

was a misfire, mixed up plug wires, please delete this thread

[Barry]

I think im gonna sticky this just to embarrass you! everyone point and laugh!!!


Haha just kidding man, I did the same things many times.

[3X00-Modified]

Nevermind the L36 Injectors on a Untuned ECU... You can't run it that way your drowning the engine, it thinks they are 17lbhr injectors so it's compensating like crazy and probably at the limit already.

[MY91GT(Z)]

we all do it ill admit i have even forgot to hook up a spark plug wire once

[ifixalot]

Way back, I tuned a friends car, an Olds V-8, I had a Chevy V-8, I put his new wires on his distributor same as I would for my Chevy, the car wouldn't start. It took me awhile to figure out that an Olds distributor runs backward from a Chevy distributor. Duh!

[Slinky]

Nevermind the L36 Injectors on a Untuned ECU... You can't run it that way your drowning the engine, it thinks they are 17lbhr injectors so it's compensating like crazy and probably at the limit already.

they were supposidly from a 3400 dohc i believe

[DTMAce]

Still, till you tune the tables for fuel delivery, you are going to be wasting mega gas and running rich. But congrats on getting it going.

(This is why we need to be able to have a "miser" button. Pre-programmed mode to allow you to run the engine leaner (while still safe) so you can get good MPG. lol)