V6 Alloytec data using OBDII / Tech2 ?

[FnomnaVZ]

Hi all, I have an Op-Com for the wife's Vectra problems, and I got one of these Chinese "ELM327" OBDII interfaces for my VZ (CAN OBDII protocol : ISO 15765-4 CAN (11 bit ID, 500 kbaud))
About US$20 delivered in less than 2 weeks.

Diagnostic Code Reader CAN-BUS Car interface OBD2: eBay Motors (item 150435278968 end time Jul-18-10 04:50:53 PDT)

Just testing the free software that works ok and I'm looking at the data. One thing I see is the intake air temp is showing around 100F (38C). Is this usual? (Outside air is only about 19C).
See data in .txt file (used wOBD log export) the column is the one that starts with 114.8.

[torana355]

Im not 100% sure but i think it measures the airs temp once it is in the intake manifold which heats the air up. That is why Manifold insulators are meant to give more power ect.

[FnomnaVZ]

That would make sense.
Although I thought I saw somewhere that the IA temp sensor was with the MAF - I could be wrong?

[torana355]

That would make sense.
Although I thought I saw somewhere that the IA temp sensor was with the MAF - I could be wrong?

Im not exactly sure hey. If it is being measured at the MAF then 38c does sound high.

[2005vzute]

im pretty sure intake temperatures can vary between 30 and 60 degrees going past the valves, could it be engine bay heat heating up the intake pipes, manifold heat, or heat from valves and internal parts...it's gunna vary untill you know where it's pickin up temperature from

[FnomnaVZ]

Good point. I'll check the reading again in the morning when there's no chance of anything in there being warm.
If it's still saying 35 deg, is there a procedure for testing the intake air temp sensor?

Also, what range of voltages are the oxygen sensors meant to show when running closed loop?

[2005vzute]

smart idea fnomnavz, if it's still reading 38 degree heat on a 19 degree cold day with a cold engine, somethings wrong haha

[FnomnaVZ]

Just did another session from cold, then started the car and idled until it had warmed up a bit.
(See .txt for all temps)
Outside temp 14C
Coolant temp 51.8F = 11C
Intake Air temp 64.4F = 17.8C

So I guess they're close enough.
What would be the symptoms of bad intake air temp sensor data? Roughness, jerky gear changes?

[FnomnaVZ]

Attached chart and Excel of temps as it warms up.

[danja]

I always thought the IAT sensor was in the airbox?? Certainly was on the Ecotec.

[FnomnaVZ]

I remember my VT was more like this
http://www.installuniversity.com/lsx...r_locators.jpg
3 wires for the MAF, 2 for the IAT

But the Alloytec has just one plug with 5 wires, so I guess they're combined instead.

[diysv6]

Hi FnomnaVZ
I have been thinking about a diagnostic OBD device but never had the confidence to buy one of them, as the available information seemed very poor/scarce when related to the Alloytech 190 donk and the modifications done by Holden Australia.
The unit you cross referenced to eBay, does it have data available for all the column headings in your data downloads?
eg Fuel pressure, Manifold air Presure, vehicle speed, Ignition Advance etc?
Does it deliver any trouble codes suited to the 190kw motor?
Does it give any data about the other computers (eg. auto transmission etc.) which talk to the engine management system?
Many thanks for your help

[FnomnaVZ]

FIrstly, for $25 I think it's useful anyway.

The one I have, using the wOBD software, has all that data, except for
- Fuel Pressure(kPaG)
- Manifold Air Pressure(psi)
O2 sensor data there are 2 : "O2 Sensor 1-1 Voltage(v)" and "O2 Sensor 1-5 Voltage(v)"

I'll have to check with the other software.
I guess it gives all the trouble codes. Haven't had one yet.
I haven't seen any data from other computer modules (auto, ABS etc) so I'd say no to that. It's not like the OpCom I have for the Vectra.