Help, 4.6 Thor Cutting Out when warm

Guys and Girls

Any help on this would be grateful

I drove for about 5 miles to Tesco with no issues, did a little shop and when I came out my beauty wouldn't start. It was turning over but not firing.

Now I do have an AG LPG system fitted and my first thought was this, so I popped the bonnet and took out the fuses for this but no difference.

So whilst I was checking fuses it obviously cooled down. I tried it and it started first turn of the key. With not understanding why it started I sat there waiting for it to warm up and as it was getting to temperature it cut out.

Time for the RAC :-(

After 20mins of him basically doing the same as me his decision was the LPG system. So on the back of a truck it went.

When I got it home I completely disconnected the lpg this was to disconnect from the battery, disconnect the 2 LPG ECU's, disconnect the 2 connectors from the vaporiser, unclip the switch in the car. And the car wouldn't start. so connected them back up 1 by 1. Once the switch inside was connected and the battery and ECU's but not the Vaporiser it started so I let it get warm and you guessed it, it conked out. So let it cool and then connected the vaporiser back up and again started her and again started first time until she was getting warm and again conked out.

I'm now lost, in my view its either the LPG system or the coil packs or the fuel pump.

Any advice will be great as it is useless at the moment :-(

Cheers
Phil

The last one like that was the crank sensor.

Is that an easy replacement? Looks like it could be a needle in a hay stack :-(

Is there anyway of testing the crank sensor?

Crank sensor failure when hot is common on other makes of car. It's a particular favourite on my other car a Vauxhall Omega.

Jelleyman said:

Is there anyway of testing the crank sensor?

Click to expand...

Diagnostics live data.

hi , check that the sensor on the end of the two wires going to the vaporiser , " usually a large round aluminium pot" also has a 6ml rubber pipe going to it as well ...make sure sensor hasn't come out also that the rubber pipe hasn't come off or got a split in it ...and obviously you have lpg in the tank !!!!!! if you want p.m. me and will give you my no to call cheers mozz

Guys the plot thickens,

I connected my PC up today to see if there was A code and there was 9 :-(

Codes were

201 injector circuit/open cyl 1
202 injector circuit/open cyl 2
203 injector circuit/open cyl 3
204 injector circuit/open cyl 4
205 injector circuit/open cyl 5
206 injector circuit/open cyl 6
207 injector circuit/open cyl 7
208 injector circuit/open cyl 8
1230 - this was coming up as manufacture specific code

Any help on this guys would be great. I'm gathering this will not be the LPG system now?

Cheers

Now its cooled checked it and no codes so i'm now thinking these codes were caused whilst the RAC bloke was testing fuses and relays. Could this be correct?

does anyone have any ideas, or advice on tracing it?

Be careful here. Most multipoint LPG kits work by interrupting the signals to the injectors. It maybe because the RAC man disconnected the LPG loom but it may also be just a phantom codes as the LPG takes control of the fuelling sides of things. You need to clear the codes. Get it running and switch to LPG and see if the codes come back. You may well end up just chasing your tail looking for the cure for these faults when really this side of things is ok and it's just hic up. I had a similar thing where when the engine switched to LPG it took control of the lambdas.

doz said:

Be careful here. Most multipoint LPG kits work by interrupting the signals to the injectors. It maybe because the RAC man disconnected the LPG loom but it may also be just a phantom codes as the LPG takes control of the fuelling sides of things. You need to clear the codes. Get it running and switch to LPG and see if the codes come back. You may well end up just chasing your tail looking for the cure for these faults when really this side of things is ok and it's just hic up. I had a similar thing where when the engine switched to LPG it took control of the lambdas.

Click to expand...

Whilst true, most Multipoint LPG systems interrupt the injector signal, but feedback to the engine ECU a 'fake' injector 'response' so the ECU doesn't fault out and throw the MIL/CEL lamp on in a hissy!

well I have ordered a new crank shaft sensor which is due tomorrow. Hopefully it will be the fix but I have to start somewhere. This could be expensive lol

I once had identical symptoms- was the crank position sensor although mine is petrol only.

If it won't start, its unlikely to be the LPG as it should always start on petrol, if the engine is warm there will normally be a 30sec delay before the LPG kicks in.

Most likely the crank as others have said, but I had the exact same problem on an MG v6 which turned out to be the cam position sensor. Oddly, it was about £150 from MG, but exactly the same thing is on the gaylanders, and the LR dealer sold it for £25!!! Go figure! (that's a 2.5 v6 though, I think the cam position sensors on the RR are about £180 from memory, which is a dodgy memory!!!)

Good news it was the crank sensor. Fitted the new one this morning and been running around most of the day. Looks like it was a coincidence with the LPG and it was a red herring. Thanks for all the help guys - Datatek gets the award for first time diagnoses lol