2006 civic si won’t start won’t connect to ecu

[Joeejara]

k24a2 block
k20z3 head
Supertech 12.5:1 pistons
Manley rods
Acl bearings
Brand new Honda rear main seal
Type s ported oil pump
Drag cartel 3.2 cams
Supertech full valve train
Brand new honda timing chain,tensioner,and guides
Cometic head gasket
Felpro valve cover gasket/gromets
Homdata thermal intake/tb gaskets
Ported amm fab z3 intake manifold with grams dbw throttle body
Hasport pass and rear mounts
Skunk2 3.5” cold air intake
Skunk2 alpha header
Hybrid racing shifter cables
Exedy stage 1 clutch
Exedy 7.5 lb flywheel
Nx fogger wet nitrous system with bottle warmer
10lb bottle
Flashpro tuner
Grams 1000cc injectors
DW 265 fuel pump (e85 compatible) has relay



200 miles on fresh build. Went to start the car one day after it started up and drove beautiful previous day. Went to start the car day after and didn’t want to crank so I jumped it and it fired up no issues. Let it warm up and drove it 10 mins in the rain down the street before dying at a light in neutral. Pulled over and it wouldn’t crank or do anything. So I walked to Walmart a mile down the road got a battery, swap it in and now the car cranks but won’t turn over, temp gauge lights up and goes dead. Connect the car to a labtop and flash pro doesn’t detect ecu. Went thru all the fuses and relays and all seem good as well as the ground wires. Not sure as to where to check next

[Spunkster]

If you unplug the oxygen sensors, does it work?

[Joeejara]

I’m 99% the tune doesn’t use an o2

[Spunkster]

Have you tried unplugging them?

[Joeejara]

I have not! But can try. The battery is dead at the moment but once it’s charged up I’ll try

[Joeejara]

No luck with unplugging the o2 sensor

[Spunkster]

So after you replaced the battery it went dead again right away?

[Joeejara]

Cranks but doesn’t turn over. Had my tuner come by and plug in his computer and he says it’s the ecu and that it’s fried

[Spunkster]

But did the new battery drain right away?

[Joeejara]

No the battery was sitting that’s all

[Spunkster]

Are you talking about the new battery you just put in?

[Joeejara]

It was new 3 months ago. Been dealing with family issues and the car was stored at a close friends. Finally getting some time to getting around to the car and figured see what the forums had to say

[Spunkster]

When you jumped it, did you connect the jumper wires incorrectly?

Did it ever run with the new battery?

[Joeejara]

I know it may be commonly overlooked but all connections were correct. I am a 3rd year electrical apprentice so I understand circuitry. Positive to positive negative to negative. Car started up after the jump no issues and drove 10 mins about after warming up. Died at a light in neutral on me. Hasn’t started back up since even with a new battery

[Joeejara]

I sourced an ecu local and was going to grab it later if he’s around and hope my tuner can come back out and program the key to the ecu and tune it again