pcmhacking.net

Hi All,
First of all this is my first post so go easy if its already here... not too familiar with all the lingo yet until i delve into it.

I have a 2003 HSV Clubsport VY2 with a Harrop HTV1900 ontop the engine. the car seams to run perfectly except every now and again i get a check engine light. i had this issue once when i first got it back from tuning. they checked out the PCM and told me it went lean or something of this nature. They wanted to replace the O2 sensors which they did. but sure enough it did it again under similar conditions. seems to happen at high speed under continuous labour of engine. most recently it did it whilst in 6th gear at approx 140km/h for a sustained period. i was suprised at this as usually it doesnt happen until approx 240 km/h. There is no hesitation or anything except for the fact i pull my foot off straight away due to the warning light. my first thought is fuel pump not big enough.

i have a bluetooth and usb scantool obd2 scanner. using torque pro or the OBDwiz windows software the PCM tells me there is no stored or outstanding faults. The Check engine on lcd only stays on for approx 10 seconds. then all is fine again.

I would like to log and scan whilst using it next. i dont use it often so its easy to have all the gear in the car as its only a toy i use here and there... apparently i need to get tuner pro and some .adx files to get some info. can anyone help me with this.

just ask if you need to know more. Thanks in advance.

get it scanned with a tech2 or other such scan tool, ive had some pcms not show any faults using an elm, but on a different scantool it showed a oil pressure sensor fault. its possible you are losing oil pressure at sustained high rpm and load and may have that or a similar code, which is known to not show on a lot of elm apps.

Thanks Jayme, So ELM is really a load of rubbish then when it comes to this? ill see the guy who did it first up and try to get the code out of him. ill also see if anything with oil comes up. is there a code for low fuel rail pressure? im suspect about this as i forgot to mention it did it once going around a tight right handed hairpin that is rather steep up a hill under load. hope this may give you more information.
Cheers again.

Nothing wrong with the ELM but it can only do general codes unless you have better software. Some free software will show specific code numbers and you have to google for info. See if Tazzi's software can do it.

hey again, So i took your advice and ran tazzies software. sure enough it picked it up perfectly. i have 2 stored codes. 1X p0101 and 1X p0102. both to do with AFM. one was a wierd one like bad connection so ill test that but the other looks like out of frequency. what is the Maximum air those things can measure. i want to log it on the road and see if it goes close to it. may need to go mafless with supercharger. Also i previously had the AFM replaced as there was a chunk missing from mine. the mechanic did i swap with me. is SS and Clubsport the same AFM? im assumung so as this kinda lines up with previous comments from the people who tuned it.

Thanks for the help so far.

Seeing it's got a map sensor & would need to be replaced to 2 or 3 bar for supercharger I'm surprised the MAF sensor is still there, normally you'd tune mafless & removed the maf sensor & assoc. codes!

I have never seen a blown ls1 retain the maf... even the factory ones (At least the factory supercharged VE maloo I saw) are run mafless off the showroom floor...

Interesting. Ok... I'll get rid of it... Works perfectly for the most part. I don't recall seeing anything in the installation manual from harrop about removing it. Cheers for all the help. At least it's all a minor problem... Cheers guys.

who tuned it? normally your tuner will recommend a 2 bar sensor and remove the maf before tuning it.

I agree, people mostly do remove the maf when tuning, although its not absolutely necessary depending how much boost your runing. In this case it sounds like its generally working but your maf is struggling to meter the air. Its probably topping out and metering less air than is really going in to the engine so the computer is delivering less fuel and you are getting error codes on both the maf and the initial diagnosis of a lean condition.

Probably the car was fine and when you swapped the mafs the new one has slightly less top end tolerance or other minor differences from the previous one so at max torque for just long enough your just far enough out to get a DTC. Your options would be to obtain another maf and see how you go or probably replace the tune with an aftermarket tune set up for map and a 2 or 3 bar map sensor while removing the maf. If you attempt to replace the maf be aware that there are forgeries in the market which work poorly, and have no chance of handling the boost. Do your best to avoid shady sources and stay genuine. If you only remove the maf with no tune changes you'll have trouble.