Missing / Flat on boost .. - Page 12 - Perth-WRX.com

BLUES · #**111** 22-01-2009, 01:24 PM

Quote:

Originally Posted by RichX

I would like to ditch the AFM completely, but going an Autronic and tuned on MAP is an excercise which will cost me a few thousand

Not really - buy a second hand SM4 for $1500-$1700 and you may "lose" a few hundred (if that) when you sell it in future. You are only paying for a new tune.

gmastah · #**112** 22-01-2009, 02:25 PM

A second hand autronics will suffice and a tune depending on your requirements could be anywhere between 700-1200 including installation of the ECU...I suppose what you want from your ECU will also determine which style of ECU you could go for..

Pimpreza · #**113** 22-01-2009, 02:39 PM

If you go to SuperCrap they have a rack with different length earth straps in black, they are extremely good quality with about a 1/4" core, I'm pretty sure they will let you take a few out to see which ones fit length wise, 2 should suffice.......Battery to intake, intake to strut tower.
You'll pay through the ass if you buy a dedicated kit.

Rossco · #**114** 22-01-2009, 05:22 PM

RICH:

The voltage you see on the scan tool is at the ECU (inside the car), the ecu is earthed through the chassis (which uses a different earthing path) and is irrelivent to engine sensor earthing (through the block).

The Voltage droop we're talking about is throught the engine block, subarus are renown for poor engine earthing.

A simple piece 4ga (6mm) wire will do to test the earth issue if it exists in you case. Simply run it from under a bolt on the manifold (i.e a vacuum hose support) to the negative (-) battery terminal and see if those codes re-appear.

It's a $0 dollar fix if it resolves your issue.

Rossco · #**115** 22-01-2009, 05:25 PM

Quote:

Originally Posted by Pimpreza

Battery to intake, intake to strut tower.

Why add extra load to an already poor (8mm bolt) earth path by earthing to the strut tower?

Just earth directly to the battery. No harm no foul, but this is the simplest way.

Pimpreza · #**116** 22-01-2009, 07:07 PM

Quote:

Originally Posted by LegacyRS

Why add extra load to an already poor (8mm bolt) earth path by earthing to the strut tower?

Just earth directly to the battery. No harm no foul, but this is the simplest way.

It's the thickness of a small washer, gives the motor good earth to body as it's fairly isolated by rubber mounts everywhere.

RichX · #**117** 23-01-2009, 10:36 AM

Hey guys,

Intermittant idle problem has also now developed, rough idle at the lights on the way to work today, stalled on me. Fired it back up and WOT'd down the road and it felt really strong.

I am definitely getting an intermittant idle issue now, feels like it misses on idle and stutters there too, sometimes stalling - Which hasn't happened before.

Doing the earths this weekend! But this is sounding more and more like AFM and/or associated wiring/earthing? I guess there is a remote chance one or more of the coilpacks is still stuffed though.

No CELs/Codes on the ECU after the stall.

We see how it fairs after the earthing this weekend.

Strubaru · #**118** 23-01-2009, 10:39 AM

not sure if you've had the gearbox out but there is an earth strap that goes from the box to the pitch mount under the tmic, this may have been left off when your gearbox was reinstalled, just an idea

RichX · #**119** 23-01-2009, 10:47 AM

Gearbox never removed afaik.

If it's still playing up after the addtional earths i need more verbose logging to find out what's going on. And as it's intermittant it will have to sit in a workshop, driven daily to log the fault.

I AM going to beat this

Strubaru · #**120** 23-01-2009, 10:49 AM

so you've cleaned all the contacts inside the plugs on afm, idle valve, coilpacks etc with contact spray?

its just gonna be a process of ilimination, good luck with it mate