VN series 1 wont fire-up

[v6lux]

Hey guys, I have a Lux (LPG powered) which had a VR V6 installed. The engine died and I thought a free rebuilt VN V6 S1 engine would be a good swap into the Lux.

I know the VR anti theft system stops the injectors from operating, no problem as it is straight gas and ran fine for 14 years.

Now I got the VN S1 bolted in place, I can't get spark! Does the VN S1 Auto EXEC sedan ECU have an anti theft system too and if so, how does it work?

There is a pink wire to ECU - A6 I'm thinking this may have something to do with it. I forget why I connected the pink wire there to the Vr loom.

Perhaps I'm missing something????

Thanks in advance if someone knows how I can get this running on straight gas!

[Dayvo]

Check for error codes and see what you come up with.

[v6lux]

Check for error codes and see what you come up with.

NOPE, that is not the right answer! Thanks mate for your suggestion. Error codes will be later.

I did get it sorted after 2 bourbon and colas.

I don't have the ECU plugged in. I studied the diagram a bit longer after posting and found there is 2 pink wires, I forgot to mention they are on the pass side in a plug near the ECU.

According to the diagram, the DF module get positive independently from the ECU. I got my meter out and found one of the pink wires is the positive for the DF module. I hooked it to positive and got spark and connected the gas and it fired-up in limp mode without the ECU.

YIPEEEEE!

Now just have to wire it properly and work out the silly S1 coolant system!

[Cheap6]

Glad to hear that you have got it running. A6 is indeed the wire that is cut by the VN (Calais and VQ) anti-theft module.

If you have been (and are, albeit temporarily) running without the the ECM/PCM active you will have been running with fixed 10 degree BTDC ignition timing. Expect a radical improvement in economy and performance with an active ECM . Running the timing without light load advance i.e. retarded, will be/have been hard on the exhaust valves too.

[v6lux]

You guys are great!

If you have been (and are, albeit temporarily) running without the the ECM/PCM active you will have been running with fixed 10 degree BTDC ignition timing. Expect a radical improvement in economy and performance with an active ECM .

Idle was set at an aggressive RPM.
Thanks for the info on the default timing!

Running the timing without light load advance i.e. retarded, will be/have been hard on the exhaust valves too.

Thanks too, I never knew that.


I got a question on the S1 coolant water system heater and header tank pipework. I figure I can just run the heater hoses as normal, ditch the header tank because I have a radiator cap and the question is -
Which way is the water supposed to flow in the small T pipe front of inlet manifold and Is it OK if I join the 2 water pipes (with metal tube in smaller pipe) that were going to the front of the header tank as there is an extra outlet to deal with?

[v6lux]

Check for error codes and see what you come up with.

Just tried to do the error code thing with a light from the VN dash (bridged wires diag plug, ignition on) - NO flashes.

I got this thing running in limp mode, but it's not a good thing - revs too high. No tacho, no cooling fan control, backfires out exhaust on shut-down!

I have 12v to lamp, but no earth control from ECU (A5) for error codes. I have proven earths to ECU pins. Is there some earth needed, not shown in the diagrams?

[Cheap6]

I have D6,A12,D10,D1 and D3 as the earths.

A6 is the signal to the ECM that the ignition is on - C16 and B1 are constant power for the ECM.

If the three power wires and the earths are connected you should get the error codes i.e. with A9 connected to earth, A5 should be earthed by the ECM in the fault code sequences - regardless of anything else being connected or not.

[NPreston]

I am in the process of fitting a series 1 into a VC Commodore and to eliminate the plastic pressurised header tank you will need as you already have a radiator with pressure cap to which you will need to add a 9mm tube to the header tank as high up and close to the radiator cap for the crossover pipe from the inlet manifold. Also block off the outlet from the heater pipe that originally went to the header tank.

[v6lux]

you will need to add a 9mm tube to the header tank as high up and close to the radiator cap for the crossover pipe from the inlet manifold. Also block off the outlet from the heater pipe that originally went to the header tank.

Thanks for that. Is this something that is urgent if I'm driving around doing test runs?

[NPreston]

Don't know. You may get hot spots if there is an airlock. I think that the crossover pipe is a bleed valve of sorts.

[v6lux]

You may get hot spots if there is an airlock.

I thought the same thing last night and first job this morning was to rectify it. My top hose is joined with a brass tube, so I drilled a hole and modified a brass threaded barb with an angle grinder and got it silver soldered to make a junction

There is now hot water flowing through it.

Just have to sort out a terminator for the bigger hose a bit better that a spark plug.(see pictures)

All that is really left to do is tidy-up the wires and get the ECU to work. still no check light on ignition "on" - eng not running. Reading through the GMH manual, it points to an earth missing, but all connector pins are earthed, so now it leads me to think the ECU is buggered, as the lamp works when I earth the globe to the case of the ECU!

[v6lux]

Piccy of how the conversion is going -

[NPreston]

I was a little more professional, I didn't use a spark plug. As my VC is for the track I cut the heater pipes, crimped them and welded them closed. Looking forward to how it will run as it is supposed to have a bit over 300 horsepower. I still have a fair bit to do as yet. Radiator should be here next week, then clutch, tailshaft and computer.

[v6lux]

I got it all sorted now.

ECU working and running smooth-as.

My mistake, I only connected 1 of the 2 pink wires, so A6 was getting 0V. (Dunce cap and less beer goggles for me!)