[VR V6] code 33, MAP sensor high voltage & missfiring

[nathanVY]

hey everyone,

just replaced my leads and plugs today, still misses! can anyone tell me what the gap should be for my car? and what to do about the MAP sensor/ any other ideas?


thanks

 

[Brett_jjj]

Plug gap should be 1.5 mm.Try resetting the ECU by disconnecting the battery for a couple of minutes.This will clear the error code.Go for a drive (15 20 minutes) and see if the error returns.It might be a one off error which can sometimes happen,if your lucky.You could also try borrowing a coil from a mates car and swap it with each of your 3 coils one at a time, just to make sure its not one of the coils causing the misfire.I would replace the 3 at the same time,especially if they have the cylinder numbers on them,which means they are the original coils.If you do have to replace them,try to buy genuine holden ones.

 

[Fenners]

yeh plug gap and coils is a good place to start, also make sure that the vacuum line is still connected to the engine and map sensor.

 

[Fenners]

also if the vacuum line is off it can give ruff idle which could be a mistaken as a misfire.

 

[nathanVY]

i did the coil pack switch thing with a new coil pack, all of them check out ok. no difference to idle with the new one in. ill check plug gaps, can someone explain where the vacuum/map sensor is? maybe some pics with highlights?

EDIT: did the ECU reset too, ive yet to check the error codes again.
EDIT2: just checked error codes and the code 33 doesn't seem to be coming up now, just got 12 for ages. still missfiring/idling rough.

 

[nathanVY]

what's the best way to gap the plugs at 1.5mm, we did gap them but I have a feeling it was too big.
what can I use that is exactly 1.5mm so we know for sure?

 

[VS_Pete]

Set of Feeler gauge supercheap mate.

 

[nathanVY]

thanks ill look into that. can someone tell me how to/where the vaccum hose is that goes in the MAP?

 

[Cheap6]

thanks ill look into that. can someone tell me how to/where the vaccum hose is that goes in the MAP?

Easiest to start at the MAP sensor and follow the hose back. If it's not connected then look for the nipple, which will be on the elbow into the inlet manifold just downstream of the throttle body.

The MAP sensor is mounted on the firewall, LHS of the ngine bay. Green plug with three electrical pins in it.

 

[nathanVY]

thanks just checked and its all connected. would a video/audio recording of what it sounds like at different revs help? is this a serious problem that could get worse on long drives?