VS motor/elec/fuel/spark problem

[Siggers86]

Howdy Folks,

let me start from the beginning, my VS has done about 400k and the bottom end has packed it in, so got a new motor from the wreckers and they promise me it was out of a going VS ute...

Upon trying to get it to the workshop, I had allot of problems starting it, as if it was a low battery and hard to turn the motor over, it went for about 5 mins then stopped again and couldn't get it going again as it wouldn't turn over fast enough.

SO I put the "new motor" in including the wiring loom it came with, patched everything in and done up every bolt etc... After gettin it towed there...

Went to turn it over, and its just turns over and over, spray a bit of start ya bastard down the guts of it, fires up a bit...

Now the fuel pump doesn't do its pre 3 second thing on the ignition... but it comes on after you try and turn it over and put the key back to ignition, so I hard wired it in for testing purposes, still no go, had a mate check injector pulse and spark, he said it has some spark, but no injector pulse, so I changed out the crank angle sensor (as he suggested), I also changed the plugs and the coil packs.

I thought maybe the fuel reg wasn't working so I partially blocked the return hose to try and build some pressure up...

So I tried to check the engine codes but noticed no engine light upon turning the ignition on and when the wires are bridged... I did accidently cross over some of the others ones on there as I forgot which one it was...

I have also changed the computer out too, swapped around the relays and checked all fuses, still nothing...

Im about to test all voltages to the computer to check what they read, but from what I can tell, with no engine light means no computer power???

I seriously am about to loose it, if I already haven't got some screws loose, any ideas and suggestions would be fantastic...

[hako]

Sounds to me like the immobiliser is still on and preventing the car from starting. Check that the red flashing LED below the radio goes out when you try to start - if it stays on it means the immobiliser is on - the way to overcome that is to leave the ignition on for about an hour till the immobiliser is turned off and then start the car....you will only have one chance and then you have to wait another hour till it turns off again. Also you need a very good battery to start a Commodore...half flat and it will crank but the electronics won't work and the car won't start.

[Siggers86]

Yes the light doesn't flash, and yes after installing the new motor, a brand new battery was used and a jumper pack at the same time and turns over great...

[Brett_jjj]

Id be checking all the wiring connections in the engine bay.There could be just a bad connection somewhere.Especially around the DFI module.

[db_notso]

check the fuse for the engine computer before you lose it
is there poer at the computer?
if its the same motor as your last car you should be using your old computer as it is linked to your immobiliser system in other computers
if the engine light isnt on that mean that circuit isnt responding likely to be a power issue with the ecu
check ALL fuses relays (are installed and have power)
e.g. ecm fuse main relay etc etc
after these are okay and you have an engine light which means the ecu is working then you can look further into the problem

[Siggers86]

This was changed out with the new coil packs, plug is in A1 condition as well, but that wouldn't explain no injector pulse or no engine light...

[db_notso]

the engine light should be on on ignition on,..... see above!~

[Siggers86]

As stated all fuses have been checked and are in in good condition, tomorrow i will be beginning to check all voltages etc...

[Brett_jjj]

A bad electrical connection could easily cause no injector pulse or no engine light.Especially if its in the part of the loom or its connectors that supplies power to the ECU.

[Siggers86]

Well I guess its just down to checking to see if the ECU has power etc... There is nothing else it could be? All other dash lights come on, oil pressure, abs etc...

[cander24]

if its the same motor as your last car you should be using your old computer as it is linked to your immobiliser system in other computers

Not in a vs. The BCM and PCM are not code linked so the PCM can be swapped with another vs BCM without a problem. VATS do exist in a VS electrical system, but as long as your security light is out then you should have an injector pulse. (when the light flashes the PCM cuts power to injector pulse).
How did you confirm you have injector pulse? Just because you have constant power to each red injector wire at 'ignition' doesn't mean you have a pulse. The pulse comes from the other coloured wire at each injector which switches to earth to complete the momentary circuit. You need to check for this with a 'noid lite' as the pulse it too quick to check with anything else. A noid lite is basically a small light globe that you plug into the injector socket and with the engine cranking/running will flash the light with each pulse. Hope that helps

[cander24]

Something else to check. Are you certain your fuel lines are correct at the firewall? The hard line on the firewall and the flexible hose to the fuel rail should be easily identified as there shoule be a matching white band on the return line. If this band is missing, the return line is on the drivers side fuel rail with the pressure reg.
Since you've been cranking for so long its unlikely to be your problem, but air in the lines since they've been disconnected won't help your case. Disconnect the supply hose from the firewall and then slip over another random piece of flexible hose into a bottle. Then have someone turn on the ignition to prime the pump. As it wont be able to built up pressure due to the disconnected line it will keep pumping as long as the ignition is on. Id do this for maybe a few hundred millilitres then connect back up. This will help remove air in the lines.
Also, did you plug in all of the plugs at the PCM? Apart from the two pink and one blue plug that plug direct into the PCM, just a bit further away from these plugs in the same engine harness will be another white/straw coloured plug that connects to a loom running under your dash. Amongst other things, this plug provides constant and ignition power to the PCM as well as one of the earth's.
Also check for a good connection with the two plugs located on the drivers side behind the strut tower. Once again, amongst other things two of the wires here are part of the circuitry for the fuel pump prime controlled off the PCM (green wire with white trace from memory) and injector pulse. Good Luck!

[Siggers86]

How did you confirm you have injector pulse? Just because you have constant power to each red injector wire at 'ignition' doesn't mean you have a pulse. The pulse comes from the other coloured wire at each injector which switches to earth to complete the momentary circuit. You need to check for this with a 'noid lite' as the pulse it too quick to check with anything else. A noid lite is basically a small light globe that you plug into the injector socket and with the engine cranking/running will flash the light with each pulse. Hope that helps

I said I didn't have injector pulse, and yep I did check with a noid light.

omething else to check. Are you certain your fuel lines are correct at the firewall?

Yes I am 110% positive they are the right way, and I have primed the fuel around the injector rail and out through the fuel reg.

Also, did you plug in all of the plugs at the PCM? Apart from the two pink and one blue plug that plug direct into the PCM, just a bit further away from these plugs in the same engine harness will be another white/straw coloured plug that connects to a loom running under your dash. Amongst other things, this plug provides constant and ignition power to the PCM as well as one of the earth's.

Tell me more about this, I didn't see anything in the wiring diagram I have... There is a few plugs up there I am not sure what they are, as I didn't unplug this old harness my mate wasn't much help in remembering what he unplugged...

lso check for a good connection with the two plugs located on the drivers side behind the strut tower. Once again, amongst other things two of the wires here are part of the circuitry for the fuel pump prime controlled off the PCM (green wire with white trace from memory) and injector pulse.

From memory they are orange and green? they have about 10 prongs in each, I have checked them, they come out right next the the throttle cable?

[cander24]

Ah, ok I misread and thought you did have a pulse.
Ok the plug I am referring to is about 1cm x 4cm (end on) from memory and is like an opaque/straw colour with about 8 wires. Go to your PCM and follow the wiring back to the inside side of the firewall. Between the PCM plugs and the firewall there is only one plug in this harness. If it's not already been plugged in then you should find the other half to this plug somewhere here under the dash. Im at work so I dont have any of my diagrams handy, but from memory this will already be plugged in as some of the other functions you've mentioned are working.
And yes the other ones are located next to the throttle cable. Will the pump prime on 'ignition' now when controlled off the PCM? As I said I dont have a diagram handy at the moment, but im thinking now green with white trace is injector pulse signal and either purple or pink for fuel pump. It's definately purple for the pump where it runs inside the cabin, but I think it may be pink in the engine bay wiring. I remember that both wires im referring to are on the one plug and in opposite corners of it.