stock VX L67 log wanted please

[firebug]

Hi guys,

The O2 sensors are immediately after the primary collectors. Yes system is 2.5" with only one muffler.

[Holden202T]

we tried running it without the o2's connected, no difference

[vlt304]

a dumb question but do you have good voltage to the injectors? if there is a voltage drop they will deliver less fuel.

[0081]

Did you happen to change the plugs and fit some with a different gap?
I noticed my afr's changed quite a bit when i fitted new plugs with a smaller gap

[yoda69]

If the intake tube around the maf has changed may be causing problems.
Air needs to have a clean shot before and after it like factory setup.
Can also be upset if it is moved too close to throttle body as at low throttle inputs air is sucked past where the throttle butterfly is and may not go evenly through the maf which basically measures flow where the heated resistor is.

[The1]

I know its a silly question. Maf installed in the wrong direction?

yeah we checked the maf, its got the arrow pointing towards the TB ....

i've compared alot of sensors to logs posted and most things look right, ie. same rpm, maf hz and cyl air numbers and g/s etc at the same points.

the only thing possibly is jayme said the o2's were pulsing, this was with the ignition on and engine not running..... not sure if thats normal or not ...

i did also notice this motor has a fair bit less timing at idle, but if anything i would say less timing would make it richer .....

im going to try a bog stock original with just vats removed and see how that goes, and check a few bits and pieces and see what comes from it.

If it's an Auto timing at idle will be different to park and drive, in Drive you should have the timing you specify in the table.

Idle AFR will also vary, if in park will goto open loop after 10seconds, if in drive it will remain in closed loop idle. So leave it in Park and see what happens to AFR's after 10 seconds. If they return to normal targets then o2's would be stuffed if they dont meet the target still then somethings out, airleak etc

[Holden202T]

we've only ever had it in park so far!

pipe from maf to throttle body is 100% stock, the pipe into the air box is different though....

would I not be correct though in thinking that if comparing to another car, g/s, cylair, and maf hz are all pretty much the same, wouldn't that mean its not an air flow difference ....

the other thing that doesn't seem to make sense is the inj pulse time is bigger than the stocker times I've looked at, that should mean its going to be richer ?

makes me wonder if we disconnect the maf wires and see if it runs better !!

[yoda69]

Would tend to agree that if all maf readings are about the same shouldn't be that.
Only other 2 things I can think of are:
1. Carbon Canister Purge, but fuelling should still be adjusted by O2 sensors and I believe is only used when running stoich afr
2. Dual speed fuel pump, used to run low speed at idle. If anything this should have made it run rich, not lean.

Given it's only ad idle, it does sound like a small air leak somewhere.

[Holden202T]

yeah canister purge is not connected to the canister, so need to check that, but i did cover the hose and it wasn't sucking any air at the time, so not sure ....

it does have different inlet pipe and pod type filter so i'll check this as well to see if theres anything there

[vs ss]

Has the little vacuum pipe under the throttle body come off?
Is the brake booster ok?