More LS430 issues..

[Micholas]

So another week, another problem on my 2001 LPG converted LS430 (getting tiresome now). Sorry this is an essay but I wanted to capture as much info as possible.

Firstly the car sat for a few days at the airport car park as I went abroad, when I came back to it, it was as if the Battery was flat (it’s a genuine Toyota Battery that’s 18 months old, car does a lot of long drives). When I opened the bonnet to inspect I heard the ping of keyless entry as if it had come back to life. It then fired up with no issues and drove home fine. I shrugged it off and forgot about it.

On Thursday I took it to a garage to replace the rocker cover gaskets as they were haemorrhaging oil. Picked the car up and it drove home fine. 

Friday morning the same flat Battery issue, I wriggled the Battery cable this time and it fired up, but this time the car was very lumpy on idle and the EML was flashing. I drove it up the road but it was running like a sack of potato’s, so I took it home. Turned it off and on, and the EML was gone and it drove 30 miles to work fine.

Lunchtime the EML was flashing again, but again I drove it up the road pulled over wriggled the Battery cable, turned it off and on and it ran fine. However at the end of the day when I was going to drive home, the EML stayed on and the VSC lights came on. I couldn’t shake these off, no matter what I did. It was lumpy at cold, but drove home fine when warm. I don’t have a code reader so not sure what the EML was for.

When I got home I disconnected the Battery to reset the ECU, contact cleaned all the Battery terminals and put a trickle charger on the Battery over night. 

This morning the VSC lights had gone, but the EML was flashing and it was idling lumpy.. but once the engine warmed up the EML stopped flashing and it drove around the block fine. 

I’m thinking this is two separate issues and unrelated? The Battery issue, perhaps a faulting negative lead, or a dying Battery.. 

And then this cold start issue I have no idea. Maybe relating to something the mechanic did when changing the gaskets. You have to strip a lot to take the cam covers off! I took the engine cover off and couldn’t see anything left disconnected! 
 

Any ideas? Or just take it back to the garage. 

[lex - eleven]

No idea why it's happening but reading your initial first line - is it possible that it's something to do with the lpg system? Hope you get to the bottom of it quickly.

[Micholas]

This is one of the pains of owning an LPG car. Dealerships and regular mechanics don’t want to get involved, and the pool of garages that specialise in them are few and far between. My nearest is 3 hours away, and if I’m being honest they’re pretty rubbish. It took me a long time to find a garage that would do my rocker cover gaskets! Soon as they hear LPG they don’t want to know.
 

If I could go back I wouldn’t have bought an LPG car. 

[cruisermark]

How about Japex in Kings Langley?

[Micholas]

It’s 2.5 hours away.. but if my garage turn around and say they can’t do nothing, it’s LPG, they don’t have the diagnostic diagrams etc etc. then I’ll certainly give them a shout. 

[Micholas]

Anyone know why the VSC lights sometimes run in tangent with the EML? I’ve read a lot about LS430 owners having VSC lights come on when they have engine problems. The whole paper clip in the diagnostic socket scenario. 

It all took a turn for the worse later this morning. VSC and permanent EML back on. I’m leaving it this time so the garage can at least run the codes.. but I’m sure this is nothing to do with the VSC. Car actually drives fine after the initial 20 seconds of roughness when cold. 

[lex - eleven]

The engine light on my 2000 ls430 stayed on for 2 years without any running issues at all.

[Micholas]

15 minutes ago, lex - eleven said:

The engine light on my 2000 ls430 stayed on for 2 years without any running issues at all.

I’ve actually had the common P0171 EML for a year or so on mine. Never effected running at all and once cleared it doesn’t come back for a while. I last cleared it 2000 miles ago and it hadn’t returned. Not related to the current issue at all I’m sure. 

[lex - eleven]

Someone suggested to me the maf sensor could be faulty. I bought a cheap Chinese item from eBay and voila no engine light. About a year later the engine wouldn't rev up. Called the Rac and diagnosed the maf again. As I tend to not throw stuff away too quickly the original was still in the glovebox. I gave it to him, he fitted it, problem solved - albeit the engine light came on. Never bothered after that.

 

[cruisermark]

I've had EML in the past due to oxygen sensor

Other things it could be hole in exhaust (even a pinhole), loose or broken seal on petrol cap, loose / cracked intake pipe which would cause an imbalance in the air/fuel ratio.

In this case I would it has something to do with LPG side of things.

It might be worth investing an OBD code reader (blutooth type) - few members have mentioned Carista 

[Micholas]

Thanks chaps. I guess it’s all going to come down to what code it throws up. IF it’s the P0171 again, then yeah it’s going to be long trial and error of MAF, O2 sensors, fuel and air lines etc etc.. but I honestly can’t see a bank 1 fuel/air imbalance causing all this. When I fire it up, the engine is seriously lumpy and rough. Unless I’ve got a huge hole on my intake manifold or something. But then why would it run normally after 20-30 seconds? Bizarre.
 

Just praying it’s not the LPG system, as taking it all the way to the specialist and having to leave it for days will be a massive inconvenience I don’t need right now. 

[messi]

It wont have anything to do with the lpg system fitted. 

If it runs rough sometimes and engine light was flashing, that's a misfire and most probably a coilpack issue. I had an sc430 with the same problem, on mine it was the 1 coilpack and 1 oil control valve.

[Herbie]

13 minutes ago, Micholas said:

Just praying it’s not the LPG system,

It won't be.

However, if you want to check, just pull the fuses and make the LPG system inoperative so that the car has no choice but to run on the petrol system only. To be honest, the car thinks it's running on petrol anyway; it neither knows nor cares that the signals from the car ECU to the petrol injectors are being intercepted and diverted to the gas ECU and gas injectors.

[BigBoomer]

Never had LPG but don't most systems start on petrol then switch to LPG after 20-30 secs?

[Herbie]

2 minutes ago, BigBoomer said:

Never had LPG but don't most systems start on petrol then switch to LPG after 20-30 secs?

Yes, that's correct.

[ambermarine]

The engine running rough for a period before transiting to smooth is indicative of sensor issues in the exhaust.If the sensor heater is faulty the signal sent  to the ECU will be out of sync until the sensor heats up.

Try heating up the sensors with a gas torch before starting the engine from cold and this might show up the theory of bad sensors.

Do them individually upside and downside . 

[Micholas]

On 9/17/2022 at 4:54 PM, messi said:

It wont have anything to do with the lpg system fitted. 

If it runs rough sometimes and engine light was flashing, that's a misfire and most probably a coilpack issue. I had an sc430 with the same problem, on mine it was the 1 coilpack and 1 oil control valve.

Well it did turn out to be faulting coils! Cylinders 1 and 7! 
 

I know how sensitive coils can be.. so with the mechanic removing them for the rocker cover gaskets it must have knocked two of them out. I’ve just driven the car home from the garage and it’s fine. However the real test will be whether it’s fine tomorrow morning.. 

I’ve known many a car where you start replacing a couple of ignition coils and then before you know it you’re in for a full set. 
 

Fingers crossed mine isn’t one of them!