Troubleshooting: Engine cutting out when cold

[carrot]

Hi all!

I've got a bit of a strange problem with my 2000 V6 prado on LPG. Sometimes the engine suddenly cuts out while I'm driving. I usually wait about 15 seconds, then crank the engine over for about 6-8 seconds before it starts again.

It always happens in the morning, as I'm slowing down approaching the first stop after leaving my driveway (about 150m), on the first trip of the day. I don't recall this happening under any other circumstances. I'm off the accelerator, onto the brakes, revs drop below 1000rpm, then I hear a few solenoids clicking and I roll silently to a stop. I think it is more likely to occur when I'm in a rush

It happened about 3 times last year, spaced out through the year. This year it happened maybe 10 times, and there was one week when it happened almost every day.

And no, I haven't done anything about it. I guess at first it happened so infrequently and randomly that I just hoped the problem would go away.

Any ideas?

[simkell]

on petrol or gas, or both?

[carrot]

On gas. I'm always driving on gas.

[howsie]

Is it only on cold mornings. Feel the condensor for the gas system it should be at minimum warm if its cold is say you have a partially blocked heater hose.

[carrot]

Ok thanks! I'll try starting the car on the driveway and seeing how long the condenser takes to warm. I would have thought it would take a km or two to start warming up... How quickly should it warm?

[howsie]

It should warm up within a minute or two. I should also mention a ba falcon I had had the same issue with the auto trans if I drove it nicely it was fine but as soon as i gave it some or put it in manual mode if within the first 5 mins of driving on a cold start it would stall the car as a safe guard against damage to the gearbox.

[Nat84]

it maybe the throttle body the air by pass valve on it

[carrot]

it maybe the throttle body the air by pass valve on it

Hmmm... Could you elaborate on that?

I monitored the warming up this morning. It took about three minutes of idling for the condenser to start to feel warmer.

[tas80]

I had very similar symptoms on my old 80 series, it would very occasionally cut out while coasting into roundabouts or traffic lights, eventually I tracked the problem down to the Fuel lock Control relay, this looks a lot like a normal driving light relay, it takes a a signal from the ignition coil to sense the engine is running which energises the relay, the relay is then the one that controls whether your gas solenoids are open or closed. It seemed that occasionally when coasting into lights the relay would think that the engine had stopped so it would then close the gas solenoids which of course stalled the engine, cost about $50 to replace.

[stilivn]

I had very similar symptoms on my old 80 series, it would very occasionally cut out while coasting into roundabouts or traffic lights, eventually I tracked the problem down to the Fuel lock Control relay, this looks a lot like a normal driving light relay, it takes a a signal from the ignition coil to sense the engine is running which energises the relay, the relay is then the one that controls whether your gas solenoids are open or closed. It seemed that occasionally when coasting into lights the relay would think that the engine had stopped so it would then close the gas solenoids which of course stalled the engine, cost about $50 to replace.

That sounds exactly like what my 80 is doing, only it is every time i put the clutch in unless i give the right foot a tap. Would only do it under heavy acceleration then stopping like at top of hill to start with.
How did you test it was this relay or did you just start replacing things and get lucky.