BH5 idle staling issues

[thorpy]

Hi all

My wifes GTB is having some issues and hopefully someone on here might be able to give me some insight before i spend $$ at the mechanics.

When cold it idles very rough and almost stalls

when driving it will randomly cough and splutter and limit revs to about 1900rpm

also power light has been coming on sometimes.

none of this has bought up any CEL's

Have cleaned the AFM with no improvement.

Car is a 2000 GTB E-tune.

Thanks

Thorpy

[Guest the_return_of_the_jedi]

does it have a pod filter?

[thorpy]

Nope totally stock except a rear section bolt on exhaust

[subieboy]

Replace your AFM...

Or you could open it up and resolder all the joints...

[log1call]

You could check for small vacumm hoses off.

Perhaps change the fuel filter and spark plugs perhaps?

Depends how confident/able you are under the bonnet.

First thing is to do a standard tune-up which should do both those suggested things, then see what happens or what else is discovered under there.

[Guest]

Tends to be the AFM - just replace the afm insert so its relatively cheap

[log1call]

Well, there are ways to test the AFM.... if you would like to verify that before spending the money?

[suubyduuby]

 log1call said:

Well, there are ways to test the AFM.... if you would like to verify that before spending the money?

Yup, see instructions for AFM testing here:

http://www.tnndesign.com/cs/afm.pdf

(This is an extract from the Twin Turbo fault diagnosis PDF I have...)

[thorpy]

Well a bit of an update on this.

Took it to a subaru specialist - 2 Hours labour and unable to identify any faults no codes everything suposedly running normal , Cost $220

Replaced AFM , no change Cost $225

New ECU,everything fixed , drives like a dream , has never driven so good in 2 years we have owned it, trans , steering , acceleration , everything is 300% better Cost $100

[Guest the_return_of_the_jedi]

ecu ? weird...

maybe someone swapped the original out in the first place?

[keeweechris]

Hi Thorpy,

How'd you know it was the ecu? Was it just trial-error? Or are there signs that the ecu is dying?

And what dies in an ecu?

[subieboy]

 thorpy said:

Well a bit of an update on this.

Took it to a subaru specialist - 2 Hours labour and unable to identify any faults no codes everything suposedly running normal , Cost $220

Replaced AFM , no change Cost $225

New ECU,everything fixed , drives like a dream , has never driven so good in 2 years we have owned it, trans , steering , acceleration , everything is 300% better Cost $100

Had a quick thought did you jump start the car at some stage...

[Guest jakesternz]

 thorpy said:

Well a bit of an update on this.

Took it to a subaru specialist - 2 Hours labour and unable to identify any faults no codes everything suposedly running normal , Cost $220

Replaced AFM , no change Cost $225

New ECU,everything fixed , drives like a dream , has never driven so good in 2 years we have owned it, trans , steering , acceleration , everything is 300% better Cost $100

Great to see you fixed your issue. Where did u pick the ECU up from? 2nd hand or new?

I am having similar issues with idle having tried a number of things

(my car has been jump started. the dealer had to jump start it for me!)

[log1call]

If you are getting elusive, varying, intermittent codes, or no codes at all, and the car is a few years old....

Pull the ecu and have a look inside. Look for blown transistors(they can explode a piece out of the side of them), burnt resistors, cracked circuit boards, dry solder joints, leaking capacitors, water damage.

Use a magniying glass and inspect every component, circuit and joint.

It only takes a matter of minutes and given the number of things that can happen inside there, and the number of checks you could have to do to track it to there, it's best to do it earlier than later in the diagnostic process.

[Guest boostin]

The term "dry solder joints" always cracks me up. Are they meant to be wet??

[log1call]

Is that a serious question?

Dry solder joints is a reference to solder joints that have been moved or disturbed as the solder was cooling. They have a dull sometimes cracked look to them, not unlike dried out skin, mud etc.

Good solder joints are shiny and smooth.