Is200 Se 1999 Lpg Misfire, Codes Engine Light Trc

[mista_khan]

Hi

ive owned a is200 already converted on lpg professionally for around 8 months.

Ive noticed from start that it had a slight misfire on idle when on lpg, now I can notice there is a slight misfire on idle on petrol and when its on lpg the misfire is a lot more on idle and now even has affected the gears too, so when in gear on lpg it is misfiring, it also misfires as I slow down and revs bounces between 500 to 800 revs etc. Also when on lpg in idle the cat rattles due to the misfire and revs bounce between 600 and 800.

on Monday gone the engine management light came on and trc was flashing constantly, went off on Tuesday.

I got abit concerned and ordered a obd2 code reader, read the codes today and had the following:

P0300

P0301

P0302

P0304

P0306

P0172

any ideas what it could be, that's hell a lot of codes, misfire never bothered me before but now its gone worse and I am getting bothered, I was told by the guy who I bought it off it misses abit on lpg, but now its just going a lot worse.

[ColinBarber]

Random misfire seemingly across all the cylinders and an engine lean error. Looks like a fuelling issue. That could just be a single injector or two playing up, as they tend to throw up errors across multiple cylinders and not just the one they fuel, but worth getting the fuel pressure checked too.

Before you had this current issue the poor idle when cold on lpg is quite common, normally it is suggested that the engine is warmed up on petrol and then switch over to gas.

[mista_khan]

hi

yes correct and I always turn on lpg when car Is on quarter of its temp gauge or half way between fully cold and warm,

could it be that the injectors are clogged up due to lpg and could do with injector cleaner in the fuel tank?

wondering if anyone else has a is200 on lpg with similar issues?

[mista_khan]

lights have come on again, engine light flashed few times and now is on, and trc is on and off, engines rough again, gonna try removing Battery for 5 mins, clear all codes, then see which ones come back up, in the mean time going to get the spark plugs out and see what condition they are, if they are black, burnt etc ill replace them too

[mista_khan]

update,

ive checked all the plugs, all 6 are in good condition and are denso iridium, but I think I found my problem.

second plug from the driver side of the engine when taken out had oil around it , indicating to me some sort of leak, spoke to my friend he said clean the plug and clean the inside where the plug goes into the engine with just a cloth , then put the plug back in screw it tight and see how it goes and check it tomorrow.

my father tells me its a serious issue and could be piston rings?

what do you guys think ? and if it doesn't get fixed how much would I be looking at to getting it fixed i.e. changing cylinder or what ever part needed?

thanks for your help

[steve2006]

Given the problem occurs on both petrol and LPG it would appear to be spark related as this is the only common thing to both fuels as each have their own separate injection systems.

As you have removed and found a problem with one plug I would first see how it goes now,piston rings are unlikely but there have been cases of valve damage running on LPG.

[mista_khan]

okay bud, my dad scared the crap out of me as I know lexus isn't cheap and I know the cars a real gem except this one issue and its a 99 model :).

ill check the sparks again tomorrow but as you've stated, I think its worth while me getting the lpg serviced again as its does misfire only on lpg.

so tomorrow I will get the lpg serviced anyway hopefully it might help but if I find oil is on the spark plug again tomorrow, what would be my next move?

cheers buddy

[mista_khan]

guys need some advice , found the problem.

done a reader and cleared codes, after 2 days only code on there is a : p0302

ive been to two lpg specialist garages in Birmingham, one said my cylinders need replacing and my lpg system is crap, second said my lpg system is fine but its my injectors, both said between 200- 250 tops for 6 brand new cylinders plus labour.

today morning driving it on petrol car lost power for good few minutes, wouldn't go over 5 or 10 mph, which is another sign of cylinders going?

so question is do I replace all 6 cylinders ? as 3 are on one side and 3 on another or do I just get the set replaced where cylinder 2 is according to the code I have?

[mista_khan]

Hi

quick update,

lpg misfire has been fixed, it was the gas injector pipes, but I still have the other issue on petrol, happens mostly when engine is kind of cold, when I accelerate on petrol it holds back and gets stuck on 10mph, doesn't go up no matter how much I floor it,

ive been told it could be a throttle body, and they are fairly cheap to replace but question is could it be anything else causing this?

and would a faulty throttle body come up on obd2 code readers as there are no codes ever since I have had the lpg misfire fixed?

[steve2006]

I would have thought if the TB was faulty it would affect both fuels not just petrol same for the MAF.

If you switch to LPG does the car then perform normally?

[mista_khan]

@steve2006

that's correct, on lpg cars smooth and no power loss like that on petrol , give or take happens only on petrol when engines warming up on first start in the day, really confused myself on what it can be?

[mista_khan]

okay update

today engine light has come on with code on as P0175 and code pending again is p0175, reading up on it it means RICH BANK ONE MIXTURE?

but can someone break it down what that means and what could possibly cause this?

[steve2006]

Something common to both petrol and heat related ... the CTS (Coolant temperature sensor) is worth checking.

If it is giving false readings or has a poor connection it may be telling the ECU that the engine is cold and therefore the ECU will overfuel (choke) the engine.

[mista_khan]

sounds like a good start buddy,

where is it located? and is it available from euro parts or only from main dealers if it needs replacing?

also my coolant doesn't have any anti freeze in it at the minute, will be getting it done this week.

[mista_khan]

okay update,

car is still rough, after clearing codes, its gone back to engine light on and trc flashing and following codes:

P0302 and P0300 pending?

P0302 is cylinder 2 misfire, I checked all 6 spark plugs, and the second one from driver side of the engine had oil on it, most likely the culprit and which is leaking,

question is do I need to replace all 3 cylinders on that side or just cylinder 2 ? and am I correct in saying cylinder 2 is the 2 one from the driver side ?

[ColinBarber]

Cylinder 1 is the front of the engine, nearest the timing belt/pulleys, with 6 at the back nearest the transmission.

[mista_khan]

so im correct in saying cylinder 2 is the second one from the front of the engine? so its not the one with the oily spark plug then?

and am I correct in saying cylinder misfire is due to the cylinder and not the injector?

[ColinBarber]

Yes, cylinder 2 is second from front. Cylinder misfire could be caused by spark plug, coil pack or fuel injector and the cylinder reported isn't always to cylinder causing the problem, especially when an injector is causing the problem in which case you sometimes see multiple cylinder error codes being triggered by a single injector fault.

[mista_khan]

okay cleared codes, swapped coil packs from cylinder 1 to 2 and 2 to 1, keeping the wires the same, just swapped the coil packs that go into the spark plugs,

ive driven it around 7 miles on petrol, no lights, no misfire, and the power loss is only minimal, but on lpg I can smell gas in the car which means maybe injector leak, going to drive it on petrol for next few days, if no more lights come on, going to get the lpg system checked after.

question is how has the error gone away on cylinder 2 just by swapping coil packs?

[mista_khan]

error Is back on cylinder 2, ive got 2 brand new coil packs at home, so will be changing coil pack on number 2, iridium spark plugs been in the car for 2 years or less so cant be sparks?

and also how can I test coil pack to see if its good or bad?

whats the standard resistance on the is200 coil packs/

[ColinBarber]

You cannot measure the resistance of the IS200 coil packs. They have a built in electronic igniter so you cannot measure the actual coil from the terminal connections. The only way to test according to the repair manual is to replace with another to see if that resolves the issue.

[mista_khan]

okay mate, got two brand new coil packs off eBay, will swap tomorrow to see a difference, if that isn't the cause to the misfire in cylinder 2, can it be spark plugs or the injectors itself?

[ColinBarber]

Yes it could be a plug or a fuel injector. Easiest would be to swap plugs around to see if the fault moves before going near the fuel injectors as you will need to replace the o-rings when you remove them otherwise you will probably get a leak.

The fuel injector resistance should be between 13.4 and 14.2 ohms at 20 deg C, which you can check without having to remove them, however they can still leak or be partially blocked even if the coil resistance is fine so you cannot just rely on that test.

[mista_khan]

Hi

collected car of the lpg guy today, his fixed the leak and the engine code, but the misfire is still present, his told me lpg system is fine and the misfire is definitely there on petrol too so its the engine related.

His told me I should replace spark plugs to standard copper core ones as they work better with lpg cars, can anyone recommend me standard copper core spark plugs or tell me what is the spark plug number for lexus is200 so I can check them up?

also ive swapped coil pack 2 which was always coming up on cylinder 2 misfire, hopefully this might help.

[ColinBarber]

what make/model of plugs are currently being used?