engine wont start VT V6

[mada Vt]

i have a problem, yesterday my car was running rough, on start it would rev as high as 2000 then drop back to normal revs after about 60 secs then the engine light would appear. I took it for a drive and i had little power.I did an error code check and got code 23 which is the air temp sensor. As i have a clean air filter i changed the sensor but that made no change at all and i still had the same error code even after clearing it. I decided to leave the battery disconnected over night. Connected it back up this morning check for errors and all i got is code 12 which means all is ok there. But now it wont start at all. Fuel pump is working. Any suggestions.
cheers

[mada Vt]

tested coil packs and crank angle sensor and they are all good, next any 1 ?

[acarmody]

Check the Air Flow Meter. First check that the plug is in properly and than try swapping it out for another.

If you give it a bit of juice will it stay consistent or will it still die?

[mada Vt]

it wont even fire up since i disconnected the battery so i cant check that. I have flattened my battery again trying to start it. It be something stupid once i find it. I did notice the last time i cranked it it almost went but stopped and i got a glimpse of a puff of smoke over the other side of the throttle body, i suspected the injector harness, checked all around there nothing is loose, nothing smelt like it burnt. My motor is clean as so its easy to see if anything isnt sitting right, loose connection, leaks etc. Motor is normally perfect except for this electrical thing thats pissing me off.

[mada Vt]

HELP NEEDED TO SOLVE THIS ONE> PROBLEM JUMPING ALL OVER THE SHOP !
i was up for a major service so before continuing i decided to change plugs leads etc to narrow every thing down, left the battery disconnected for a day; im confident its not the pump as i replaced not long ago and cleaned the tank, i have pressure gauge on th fuel rail. Tested all electics for volts and ohms and none have failed.

@4221 i tested and all is good. After i cleared the error code and retested and rerun the test all i got was 12 took it for a drive still ran crap did another diagnostic test and got error 72; (VSS). my car ran like this is what is wrong as it lacks power and doesnt want to rev or shift up gear hard. Im chasing my tail with this issue.Any1 got an idea on what going on. A ECU change maybe ?
i forgot to mention that when the motor fired up again the same symptoms was there, rev around 2000-2500 for about 60 sec then dropped to normal then the engine light came on. the only difference was i got error 72.... is this consistant with error code 72 or 23

i disconnected the vss plug sprayed contact cleaner, cleared the error codes again and now its running sweet

now my patience is being tested, it is now stuck in limp mode with no error codes. wtf!

the situation is now at, i have only driven th car on test runs,the prob has jumped to tranny with no error codes and seems to be in limp mode. Now i have lost 3rd and drive gear th rest i can manually shift. Put scan tool over it no error codes or even a history other than a fault with the abs and keys that had been coded previous. In diagnostics everything is running to spec. When diagnosing the tranny the solenoids couldnt be turned on or off. Strange one considering there is no fault codes at all.The motor is running perfect now. Is this because of an internal tranny prob that has made my electrics go spastic to prevent me from doing damage to the tranny. ? The auto elec that did the scan said maybe the tranny fluid needs replacing and the filter, however the fluid isnt brown or smells burnt but i have lost gears and it is way off from where i started with error code 23

some one stop me chasing my tail. by the way holden are clueless to the prob

[db_notso]

correct me but is this info correct where is 72? for a vt v6?? vss is normally vehicle speed signal yes?

[db_notso]

i am not sure if bridging will give you transmission codes or just engine codes.... maybe one in the transmission

if there are no codes and only manual select available is either mechanical fault in gearing of box OR trans ecu is dead in which case should be code like
no coms to auto stored in the engie ecu

as a disconnected solenoid wiring SHOULD set a code for open circuit IN the auto computer

[mada Vt]

correct is the vss

[db_notso]

so code 24? how did you get 72?
24 is the sensor for auto trans output speed
Error code 24: Vehicle speed sensor (VSS).
usually it requires a new sensor or the plug is disconnected
either of which would set a dtc in the auto transmission
and as in that link speedo drops out intermittantly low power as takes off in second i noticed a few times too

[mada Vt]

i didnt just bridge to get error codes but to my knowelege bridging will give all codes that are stored.... i had a sparky come over and he a did full diagnostic with scan tool and all electrics are fine, no errors on the trans . ECU is fine otherwise there would not be any communication to the ECU with the diagnostic computer. Its like something is telling my car not to function.

[mada Vt]

i never said code 24, code 23 which is the air temp sensor in the air box, not sure where you got your code list from. I think its vn - vp that code list.... VT - VY are the same. Code 72 is the vss. which explains power intermitant in the harness.

[db_notso]

okay then. so cleaning the vss plug and clearing codes and it came good
for a short drive

did any lights come on now abs for e.g.
an abs code is sometimes only present while the fault has occured in that ignition cycle

[mada Vt]

yep came good for a short while, engine purring like it should but now a glitch suddenly appeared with the auto. Very frustrating. I have had no problems with the auto. i ge my normal reds to start and when its fired the cluster is normal. No engine light is on. ABS is all good. Still no error codes.

[db_notso]

so now there is only a fault with the selection of gears in drive?
can you manualy select first gear and have normal acceleration?
same with reverse? (does reverse work normally)
does the enging idle much lower when in drive?