Intermittent start problem VS V6

[Neile]

Here's one that's driving me nuts.
Code 47 keeps coming up for one thing.
Sometimes it won't fire on petrol but if I switch to LPG it will.
The Gregory's ECU voltages check out 5V @ D4 ignition on then 3V with the engine running. I've cleaned the ECU connectors and the earth connections are good (Gregory's again).
Latest is it will sometimes cut out (or big miss) when I hit a bump then fires up and keeps going.

Is my VS possessed by the devil........should I have it exorcised?

I read a suggestion about avoiding a cut out in a 3 lane roundabout, a mighty fine suggestion. I guess I'll just stay away from the bumpy ones for the time being

[Harvs82]

Here's one that's driving me nuts.
Code 47 keeps coming up for one thing.
Sometimes it won't fire on petrol but if I switch to LPG it will.
The Gregory's ECU voltages check out 5V @ D4 ignition on then 3V with the engine running. I've cleaned the ECU connectors and the earth connections are good (Gregory's again).
Latest is it will sometimes cut out (or big miss) when I hit a bump then fires up and keeps going.

Is my VS possessed by the devil........should I have it exorcised?

I read a suggestion about avoiding a cut out in a 3 lane roundabout, a mighty fine suggestion. I guess I'll just stay away from the bumpy ones for the time being

If its code 47, then I'm pretty sure its the good old Crank Angle Sensor (CAS) that is buggered, either that or the DFI module, where the coil packs sit on. Both are linked to each other, but 99% of the time its the CAS. Just out of interest, how many km on the car?

[Neile]

Harv82, Thanks for the reply.

The cars had around 300000 K's but the engine is new (reco) about 15 to 20000km. I imagine the CAS is from the old engine and certainly the DFI is.

The strange thing is why a bump should effect the CAS. Particularly a bump which is like a bar across the road, you know a ridge like the a bad join in the asphalt. Might be the DFI it has lots of wires and connections that could be loose?

I was leaning towards the CAS but the good book (code 47) was pointing to the ECU. Why would it start OK on gas, is it fuel????????/....aaaarrrgghh!!!!!!!

If the bugger would die, preferably in the driveway here at home, at least I would be able to find what the problem was.

One more is that it had a problem where it would start on petrol then cut out after a short idle. This isn't happening anymore. Looking at the electircal diagram and the oil pressure switch circuit. On start up the pump runs about 2 seconds to build pressure then drops out again, when the oil pressure rises, after the engine starts, the pressure switch brings the fuel pump back in and holds it in. I am thinking maybe the bumps were causing the fuel pump to drop out momentarily (if the switch is a dud)

thanks again Harvs82,

Neil.

[kopper69]

I would get the CAS done. Just so common its not worth mucking about with. DFI module does go, but no where near as common. More expensive too, unless you go second hand. If CAS didnt fix it, I would get a new DFI module with the coil packs off ebay or wreckers for around $75. Try that. Also check the connector on the side of the DFI module (wouldnt hurt to take it off, spray it with some contact cleaner and reconnect). I havent read a single post on here that fixed the error 47 with the ECU. Very rare to have problems there. CAS is a magnetic sensor and it very well could be failing with a tiny bump.

Im not sure if the gas uses the CAS signal, maybe that is why it will start on gas ok?

Oil pressure switch is cheap and easy to replace if you suspect it. Im fairly sure the car will run without it though. If the CAS doesnt fix it, you could always try the oil pressure switch.

Edit: Just went outside, disconnected oil pressure switch, car will start and run fine without it. I'm fairly certain its only when the normal system fails that the car will rely on powering the fuel pump through the oil pressure switch.

[Neile]

Thanks kopper69,

I've done the contact cleaning thing on all the connectors, DFI, Oil switch, Cam and Crank, including the plugs that connect to the ECU. It seems to be starting and running better but a 5 or 10km run brought up code 47 again.

CAS it is then guys, thanks for the help.

Neil.

[Neile]

Fitted a new CAS from Moparts in Croydon ($61.95) which I think was an OK price (looked at eBay worked out about the same) starting easy and no codes after 10km run that was bringing them up before.

Thanks for your help guys.

Neil.