Jamie_B

On the Apexi commander display which sensor is the MAF shown as? I'm hoping its the one shown as bst1(1.35V) and not AF-1(0.8V).

Any help would be appreciated as I'm trying to find out why it's running rich

Thanks,

Jamie

Jolly Green Monster

iTrader: (4)

It is easier to look under the Monitor - airflow and it will be displayed in Mv.

Should be something like 1100 on idle although varies.

You haven't by chance gone into the settings - airflow and moved up or down looking at the different intake options have you? it will automatically choose the one you leave it on, you don;t need to press next to select it.. this will make it very rich if you choose a higher option number than you have fitted etc.. ie. standard intake and you select 2.

Simon

Jamie_B

Thanks Simon, I'll check it later. I haven't been near the settings since it was mapped so nothing should have changed. I've just had a new STI9 short motor fitted,unless that has changed something?

Jamie

Jolly Green Monster

iTrader: (4)

It was mapped on the previous motor??

I think the short motor from sti9 will alter the squish area depending on head gaskets used.

Jamie_B

Its currently reading 820mV on idle, does this sound like my mafs gone?

banny sti

iTrader: (68)

That sounds about right, because thats what my car reads on idle too and it is running spot on

ZEN Performance

bst1 is the factory map sensor
bst2 is boost control kit map sensor (reads 0 unless fitted)
02-1 is lambda
AF-1 is Air Flow meter ie MAF sensor

Jay m A

iTrader: (2)

Paul, (or anyone)

can you explain how the PFC sees bst1 and bst2? Is it via the same input, (and you have to configure it) or is there another loom for bst2.

I have a my93-96 PFC and am using a MY97 MAP sensor. It is under-reading the boost (1.4 bar on the boost gauge = 0.9kg/cm2 on the PFC). Is there any way of getting the PFC to read it correctly?

I can't get my head round the Apexi MAP sensor allowing boost over 1.1 on the early ones, if the OE MAP max's at 5v for 1.1 bar - how does the apexi MAP get around this, and can I do the same with the MY97 MAP I have?

hope that makes sense

Jamie_B

I think I'll take it easy until Andy maps it in August. Especially as on the dyno the other day I had a det reading of 56 on the power Fc, it still made 289bhp with 260 ft/lbs of torque.

ZEN Performance

The PowerFC will fuel cut at 0.25 bar above the target boost if the boost control kit is turned on. If the boost control kit is turned off it will not do a thing.

The BST2 is for the boost control kit map sensor, it plugs in with it's own loom to the 3 pin socket on the side of the case.

Best thing you can do is put the original map sensor back in IMHO.

Paul

Jay m A

iTrader: (2)

Many thanks.

So could I try plugging the MY97 into the BST2 port? If so how would I tell the PFC to use BST2, is it via the commander or a simple case of leaving the OE loom for the MAP sensor unplugged.

I read somewhere that an under-read MAP has a poor effect on closed loop fuelling, if so, what is it?

Lastly, if I plug the OE MAP back in to BST1, will I still be able to get 1.4 bar? I am using a Dawes to do this at present.

uber thanks

Jolly Green Monster

iTrader: (4)

>>Lastly, if I plug the OE MAP back in to BST1, will I still be able to get 1.4 bar? I am >>using a Dawes to do this at present.
Assuming was mapped for that or going to be then yes.
There is a warning that switches the cel on when you get to the max of the MAP sensor but I cannot get mine to come on.. lol I assume this is at 5volts but the OE sensor is not quite reaching this on my own car, despite me running upto 1.5bar, so although the sensor tops out at 1.2bar reading it is not at the full voltage range at that point iyswim.
You will need to set boost target to greater than 1.1bar (1.4bar) in the PFC even though you are not using it to control the boost as it will switch the CEL on if it is still at a low number like 1bar as MAP will probably read to 1.2bar and switch the CEL on due to over boost, it will not boost cut as you are controlling the boost with the dawes so the PFC cannot alter it.

Plugging the MY97 sensor into the BST2 socket might work but it is unlikely to be configured in the same way, and the same voltage = the same boost that it is expecting, but it might be nearer than the current situation.

The PFC is expecting the boost kit to be plugged into that.. I believe the AVCR map sensor and the boost kit are the same MAP sensor.

I have never had the need to purchase a boost kit yet as everyone uses a different form of boost control (dawes, AVCR, Hybrid etc) on the early car and any PFC I have fitted to one has involved fitting said boost control device or boost control was already fitted.

I have plugged the Apexi AVCR MAP sensor into the OE MAP wiring on my car and the plug coincidentally is the same but the wiring different or the voltage configuration different I haven't had time to estabilsh which yet.

I am intending purchasing a Sensor Harness when I place my next order of PFC's, later this month. The harness is part of the boost control kit and so will connect my AVCR map sensor into the PFC.. I just need to keep it wired into the AVCR as well on my car. Although it might be just as easy to use spade connectors onto the PFC socket.

At the end of the day it may well just be more straight forward to buy the boost control kit and sell you OE 3port to offset the cost.

As to under reading MAP sensor effecting closed loop - I can see it causing the ecu to remain in closed loop for longer.. the load won't be seen as much and so the ecu will remain in the lower load areas of the map for higher boost than it would normally.. so the closed loop could make it run leaner and det due to the boost being higher than it sees and it needing richer mixture than closed loop provides at that point.
Although the MAF reading will cause the ecu to see load but it will still be lower imho.
You can however turn closed loop off, obviously it needs to be mapped on the MY97 sensor is not already done.

You can turn the boost control kit on and off with the commander (etc, function select, boost control kit) but with it off it still reads the OE sensor from BST1, having not plugged a MAP sensor into BST2 I am assuming it would switch to this if there were a voltage on the socket.. but unsure until I try it on my car.

Simon

Jolly Green Monster

iTrader: (4)

Oh and I agree with Paul.. plug the oe map sensor back in.

ZEN Performance

Without the boost control kit actually fitted, you can't set the boost above 1 bar on the early PFC or it will throw and CEL. If you want the PFC to control the boost, the best way is to use the control kit. Although the later MAP sensor can sort of work, you need to make sure the duty is set quite accurately.

paul

Jay m A

iTrader: (2)

Thanks Simon and Paul

Time to play with it

Jamie_B

What reading does everyone else get?

banny sti

iTrader: (68)

i get a similar reading to yours on my car 97 sti v3, but i have a apexi dual funnel filter and that is the setting i have used on the commander.

Tone Loc

iTrader: (1)

Mine idles at about 1000mV

Tony.

Jamie_B

Thanks Tony,

I just wanted to get some sort of average before swapping the maf.

Andy.F

Simon

You are incorrect, the map sensor does not dictate whether the ECU runs closed loop or not. That is a completely different function within the ECU.

Andy

Jolly Green Monster

iTrader: (4)

Andy,

This was the only way I could see the under reading map sensor effecting closed loop.

The ecu only runs closed loop for certain areas of the map and the altered MAP reading would alter the areas of the tables the ecu used, therefore I was thinking the under reading MAP would therefore effect when the ecu went in and out of closed loop areas of the map iyswim?

I assumed it used MAP, TPS, MAF, to decide whether to use just the fuel values in the ecu tables or whether to alter them using the O2 sensor etc..

So if it doesn't use it, then how does it decide when to use closed or open loop?

No questioning you btw just interested in your opinion

Simon

Andy.F

The map sensor and TPS have zero input to the closed/open switch point.

This is dictated only by engine coolant temp, O2 sensor voltage (must have warmed up and exceeded 0.7v) and the 'trip' value in the fuel map.
The default for this is 1.047 ie table value of less than 1.047 and the ecu runs closed (subject to prevous qualifications) over this value and it runs open loop. This trip value is adjustable on FCDL (bet you were wondering what that bit was for )

Hope you find this helpful

Andy

ps - Remember me when you're rich and famous

Jolly Green Monster

iTrader: (4)

lol @ being Rich and Famous.. that would only happen if I SS* my prices..

Thanks Andy

* SS = Super Size