pcmhacking.net

Perhaps not the cause of the tune issue, but if you have the standard PCV hose arrangement, wouldn’t the fresh air connection that goes from the RH rocker cover to the throttle body pressurise the sump once the blower starts to make some manifold pressure? Or have you changed this connection to be upstream of the blower intake?

Yeah mate I have that hose going to the intake side of the blower next to the air filter.

Hey all, still chasing this surge at idle. Can anyone tell me what diode I need to remove from the ecu after adding a wideband? I have a vs auto ecu and is different to the pic in the FAQ thread

vscapricetim wrote:Hey all, still chasing this surge at idle. Can anyone tell me what diode I need to remove from the ecu after adding a wideband? I have a vs auto ecu and is different to the pic in the FAQ thread

Hey mate, are you still after this info? I have a VR V8 which is 424 ecu, is your ecu number the same?
It's a resistor, and not a diode if I remember rightly.

Hey all,

Finally getting back into the caprice again...
Yeah is it deuce and I found the one to remove, cheers

The problem I'm having now is in open loop once up to temp of over 70c I run about 13.5 afr. After it warms up a bit more its pretty good. Once I've been driving for half hr or more and getting some heatsoak into it it'll go up to 15.5 to 16 afr. Wot and on boost is still OK at 11.5.

I've tried altering the inverse temp table a little but as someone had previously mentioned the only way I can get it to stay right is by lowering the numbers for 68, 80, 92 and 104c to 10c but then my wot areas are rich.

Engine coolant varies from 89c to 97c with twin au thermos.
Mat varies from say 80c (sitting in traffic or idling for ages) to low 60c high 50c through an intercooler and about 10psi at 5600rpm.

When it's good charge temp is about 70 to 75.

Does anyone have an idea of any other setting that maybe affecting this? I've tried everything I know of

Cheers
Tim

The coolant contribution table. Dylan is the most experienced person on here in relation to tuning that table and hopefully can chime in. There is a bit of a back and forth in tuning it.

Cheers vlad01

I did look at that but seemed a bit out of my league haha

Also the hot restart goes really lean up to 19afr

Are your dead times correct for the injectors? That needs to be right first. Then it sounds like your VE might be lean and overcompensated for in warmup tables. I'd be tempted to tune VE at operating temp, then turn down the cold enrichment to bring the colder temp operating back in to line.

My opening times for 60lb seimens are

Volts ms
4.8 3.89
6.4 3.62
8.0 3.11
9.6 2.24
11.2 1.10
12.8 1.01
14.4 0.70
16.0 0 52

I've tried changing ve while at the temp and it doesn't seem to make a difference, the only thing that does is bringing the inverse table to 10c. Even bringing them all down to 50c made no difference