supercharged Vt v6 wont start

[B28]

Changed a motor in a supercharged vt v6, and now it wont start. The starter wont crank at all unless we bridge the relay pins. Tried another relay and was still the same. If we bridge the starter and get it to crank, the engine still wont run. It lets out a small backfire while trying to start it sometimes. There is good spark and fuel injectors are fine, also ecu was working fine with the old engine?
Any ideas? ? ?

 

[delcowizzid]

Did you swap engine harnesses series 1 and 2 vt have a few wiring differences at the 3 plugs by the firewall

 

[2O4TS]

Hey Delcowizzid, are you able to elaborate on your post above?

It's just to eliminate possible issues as I just dropped an 'L67' in to my car today and I'm going to be using the loom that came with the top end, mainly because of the fact it has Calais/Statesman plugs on the transmission inhibitor switch which will make the PRND321 dash lights work and frankly both my original loom and this one are heat welded to the sockets on the inhibitor switch. Unfortunately I don't know exactly what the L67 loom is from. Well my assumption is VS/VT/WH as it has the plugs to suit the ECU from those models.

And just to complicate things, I'm not exactly sure what model the body loom is out of. It's a Statesman loom I was given and I fitted that and a Statesman interior years ago with no issues whatsoever then or since.

So... being that the Stato loom worked with my L36 do you think it would be fair to assume that this L67 loom with the same ECU plugs as my original engine will be compatible with the Stato body loom I've been using the last few years?

I never anticipate things going smoothly. There's a Murphy in my ancestry somewhere for sure so if (when?) this thing is doing my head in cos it won't start (to be fair not an issue I've had with an engine build since my first as a teenager but, you know... that Murphy thing) it would be advantageous to know if this is a possible cause. Appreciate any info.

 

[Lex]

Is this a fresh install (l67, old motor was the l36)?
What have you changed? pcm with the memcal l67 tune or just the memcal?
If just the memcal, should be ok? If pcm, did you link the pcm to bcm?
Rereading your original post, sounds like you are using the new motors pcm?
If thats what you have done, put the original pcm back in with the l67 memcal.