C for Chevelle

trying to get my '69 chevelle lq9 swap fired up today and got no spark. cranks hard but wont fire at all.. if it was an older set up i'd be able to figure it out, but w/ all this technology im confused

any tips for what to look for? might be very noooob, but any tips are helpful, even the most obvious

the_merv

iTrader: (88)

Possibly the Ignition Fuse for the Coil Packs..I'm pretty sure you got them plugged in so I am not goin to say that.

350SS

iTrader: (38)

Do you have VATS programmed out of the PCM?

C for Chevelle

sorry yeah, VATS is disconnected,,

mmdb

iTrader: (1)

Hook up a noid light and check to see if the ignitors are actually firing. If not you might not have a 12+ volt supply to the ignitors. I had this happen to me. Good luck.

C for Chevelle

on the connector for the coil pack, which wire gets a constant 12 volts? there's 4 wires there.

btw '04 lq9

C for Chevelle

do those kragen diagnostic things work on this engine? if so, i'll go down there, pick one up, and see what code it flashes me

Sandmann120

iTrader: (1)

This might sound kinda simple, but check the grounds on the back of the heads. There should be 3 on the driver's side head.

bczee

iTrader: (12)

Other than spark, how about fuel pressure ? All of the injectors connected to the correct injector and getting voltage ? All of the vacuum line connected or plugged ?

Double check all of the sensors (knock, temp, maf, map, etc)

C for Chevelle

guess i should check all those sensors again... ive been thinking that there was a ground wire coming off of the engine fuse panel before the install, but there isnt one there now.. does anyone know which stud to attach the ground wire to? or does it matter when i connect it on the fuse panel? theres a few studs and a threaded hole where i could connect it, just dont know which to connect to

eagleuh1

One threaded hole should be positive hooked to the battery positive. This energises all the constant battery + circuits on the UFB. You could hook the battery positive to a post thats on the underhood fuse box also. I used a continuity tester to find which ones all interconnect. Then you should have an ignition wire from your key to the underhood fuse box that trips the relay for all the ingnition on powered circuits. But you'll need to get power to your key circuit from the underhood fuse box for this to happen.I ran two wires from the UFB to the power distribution block on my fenderwell to do this. When you have all this, you should have power at the fuses for the injectors and the coils. I'm assuming you used the oem harness and underhood fuse box. Make sure it has all the fuses and relays you need for it to work also. Good luck with it. I guess if it's cranking though you've got power to the UFB. No ground wires go to posts or holes on the UFB.

jtune

I'm not sure if it pertains to the lq9 but I know in my case (04 LS1) the VATS was programmed out using HPTuners and that software had a bug. They released a patch in april, I believe, to fix the software. After I had mine reprogrammed (and the coil packs wired because I forgot about them) it fired right up.

Jerry

C for Chevelle

im stupid,, forgot to hook up the power to the fuse block,, got me a spark now!

eagleuh1

You using your old starter relay to crank the engine then?