ANOTHER engine warning light issue. a bit different to others here

[slowandlow]

i recently bought a vt v6 on dual fuel. it came with the issue of the engine warning light coming on when running on petrol. it takes about 5 minutes to come on, and will go off if i switch over to lpg, or turn the car off then on again on petrol. i got the entire lpg system overhualed, and the motor and tranny was cactused, so i got a local wreckers to put a used motor and trans in. when i first got it back i took it for a 40 minute drive on petrol, and the engine warning light didnt come on at all. (such a nice feeling ) . the next day i drove it on lpg, and it did a big backfire. i plugged in the vacc hoses that blew off, and the airbox lid etc. then when i went to drive on petrol, and, the engine warning light came on again, same as before (after about 5 minutes). another sympton i noticed, is that when i first start on petrol and the warning light isnt on yet, there is a minor stumble at idle in drive, and as soon as the engine warning light comes on again, it idles much better (almost perfectly). it doesnt have to be cold to do any of this. if i turn the car off when its warm to reset the warning light, it happens the same way as when it was cold. im wondering if the idle learn proceedure has been done properly, and/or if this would have anything to do with the warning light, as it does seem to be an idle problem. hopefully someone out there has come across this before, any advice would be appreciated. for now i guess i can try the idle learn proceedure.

oh, i did actually take the car to a repco mechanic when it had the buggered engine in it and asked him to tell me what the warning light was about. he told me he tested it and couldnt find any fualt, and just to ignore it . i think he FOBBED me off on that one, which is strange, his other work he did for me was good i thought.

anyway, hopefully uze can help on this. cheers :thumbsup:

p.s. i changed the spark plug gap from 1.5 to 0.9 to stop the LPG backfires. i dont think this is the cause of the warning light either though, as it comes on at either spark plug gap

p.s.s if it makes any difference, its non-ABS

 

[slowandlow]

either disconnecting the battery or doing the 40 minute idle learn proceedure seems to have fixed it. i drove around for an hour today on petrol, and no warning light came on. the final test i suppose is after i use LPG, then try petrol again. fingers crossed. if it doesnt come back, i suppose it shows how important the idle learning proceedure can be after disconnecting the battery.

 

[slowandlow]

FIXED case closed!! ive thoroughly tested on lpg and petrol now, and the light behaves itself and stays OFF. i really think it was the idle learn, remembering this is a dual fuel vehicle. i think a thread needs starting to find out if idle learn is bull, or not.

 

[slowandlow]

did i say case closed?
seems my car had a new years resolution....... to f##k me over with the engine light. the prick of a thing is back.
talk about instant depression. it felt really good to think it was gone. oh well
looks like im going to have a first go at checking the fault codes, and go from there.
so embarressing huh... it went a bit further before it happened this time. skitzo bloody thing.
at least theres only a certain amount of things it could be i suppose, due to having the entire motor and trans replaced, so shouldnt be anything there.
im guessing at the maf sensor, pcm, or o2 sensors now though, as they seem to be the most relevant bits still in the car from original.
i wont blow my own bugle so fast next time
(insert appropriate swear words here)

 

[slowandlow]

finally, got the codes, 36, 44, 48, 76, and 92. put in an o2 sensor, a new low speed fan relay. now the engine light doesnt come on (really this time). i still have one code left still coming on, code 36. says in manual, could be a vaccumm leak, the IAC valve, or pcm. am getting the injectors cleaned and new o-rings, cos they such air in, and hopefully that clears the 36 (only cos i know the injectors are definately sucking, may as well start there.) if not i have the other possibilties ready to check out. mostly im pissed at that poo faced repco guy in hallam. what a great guy he is...... NOT!!!!!! (can anyone tell me why some mechanics act this way??? is it just if they dont like the look of you, or are some just pirates in disguise. i know there are some really good ones though too. some, stain the reputation of all unfortunately it seems)
i will post on the final code when i get rid of the fricking thing. i sooooo cant wait.

p.s. still i would appreciate any further suggestions on my code 36 if anyones out there........ HELLO???? anyone there?

 

[ravi_rajput2000]

I have the same problem

Hey mate....I have the same problem with my VT commodore which I bought around Six months ago from a F*****g Leb....(no offence but the guy lived upto the reputation lebs have) by selling me this piece of crap. he didn't even tell me that he had changed the engine and put in a different sppdo which shows around 150 k. i dont know what the real KM are....anyways...the warning light comes on after 5-7 minutes of driving on petrol....I am not sure buy maybe it does come on in the gas mode aswell....I am looking to sell the car now and want to fix this issue before i do it..so do you thing i should change the O2 sensors to start with??? I am not looking to spend a fortune on it....

 

[slowandlow]

i would change those first. holden gave me a pretty good price on them. it wasnt their first price.
he told me their list price on the phone, and i said" ooouucch", so he said " hmm, i can do a fair bit better than that actually".
the price he came up with was nearly half the first price

 

[slowandlow]

you should be able to find out the real klm's by calling the registration branch and asking what the previously registered klms where. if you find its wrong, and did want to change it to a speedo that is closer to the mark, just make sure it comes from a car with the same amount of airbags. otherwise, you will need to go to holden to reprogram it to your srs module (it will cause an airbag light)