v5 sti starting then dying after about 2 seconds of running

[scoobygt]

haha good on ya fellas!

[Guest]

 Eight dollar']

[quote name='Eight dollar said:

ecu use\'s cam/crank and coolant temp to start engien - all other sensors are ignored

AFM is used once engine is started , so your problem could well be that - can you fit a test unit

easiest way to see is to get it put on scan tool and do a data read out - the reason should be pretty clear

/quote]

There you go Logcall - diagnostics by actually knowing how the system operates !

Doesnt always throw a code though bro.

I have to wonder if theres something else on the circuit that throws the afm out of wack it just seems uncanny that I chewed through so many and changing to a new one fixed the problem for 1-3 months.

[log1call]

 Eight dollar']

[quote name='Eight dollar said:

ecu use\'s cam/crank and coolant temp to start engien - all other sensors are ignored

AFM is used once engine is started , so your problem could well be that - can you fit a test unit

easiest way to see is to get it put on scan tool and do a data read out - the reason should be pretty clear

/quote]

There you go Logcall - diagnostics by actually knowing how the system operates !

Yeah good thanks.

That\'s not actually a diagnosis though, but no matter.

And I do know how the system operates thanks... It\'s my job.

[Eight_dollar]

umm yes it is - why

because if the engine fires and runs for s few sec\'s everytime

It confirms that it has spark - it has fuel ! and is dying when the ECU add\'s AFM readings

Reason AFM is ignored at crank, is that airflow is too low to get stable readings ! - but hey you already knew that

Honestly dude - stop being the know it all, accept that some here actually know potentially the same or maybe more than you !

You dont actually know just who some of the members here are ............. Some have 30+yrs with factory training, Prodrive exp, etc

Just accept that everyone (including you) can have an opinion

(ps) the thumb over a fuel line test is nothing short of "russian roulette"

[log1call]

Ha, yeah, ok.

I\'m a duffus.

I agree that if you are stupid enough to squirt petrol about, it can be dangerous. Thing is, I didn\'t actually think anyone would be that stupid.

I always assume that the people asking the questions are probably amateurs, keen amateurs with a few clues. I assume that they probably don\'t have all the workshop equipment, but that they are reasonably intelligent and competent.

And... making an educated guess, is not a diagnosis.

[loner]

I think all the under 25 years olds should just shut up and stop being spoilt brats... we all know you young guys have value too... so stop crying for attention on the interweb and go do some work.

[tebbyj]

 loner said:

I think all the under 25 years olds should just shut up and stop being spoilt brats... we all know you young guys have value too... so stop crying for attention on the interweb and go do some work.

Thats not very nice :\'(

But I see your point....

[Guest]

 loner said:

I think all the under 25 years olds should just shut up and stop being spoilt brats... we all know you young guys have value too... so stop crying for attention on the interweb and go do some work.

Funny coming from the 6yo.

Can only dream of being spoilt. Ive worked for everything I have I havent got rich parents if thats pointed at me. Maturity isnt judged in years its more of a fuktardometer system imo. Sorry just have to ask were you loren on the old system/at one point? I multi task phone/CS at the same time doesnt hinder my work at all.

[Marky]

I THINK IT MIGHT BE THE AIRFLOW METER TRY THAT LOLS

[Eight_dollar]

diagnosis over the www is difficult at best, and some explanations of faults can lead to wild goose chase\'s

As is the explanations of how to check / test and repair

LOG - isnt any electronic diagnosis and educated guess until the problem is solved - going thru a logical repair sequence

diagnosis for this fault could have been AFM, wiring, interference issue, ecu or even a blocked exhaust

Easiest place to start and most common cause is AFM - not the loom , ecu , or exhaust

[log1call]

Well Eightdollar, after following all the subaru or any manufacturer\'s books right through, when every component including the wiring has been checked, we often find they say to fit a "known good unit". Generally that\'s only in the case of ecus though.. most other components there are specific tests for, and paths to follow to arrive at the conclusion that you should check that component.

That said, once cars have been modified, or played around with, then it rapidly becomes a guess.

I\'m a mechanic, I don\'t get paid for guesses that aren\'t right, or that are only half the fault, the victim of some other component failing... I have to be methodical, systematic, and careful, whether the car is modified or not, whether I know it\'s history or not, whether the fault seems obvious or not. I always start in much the same way.. In the long run, over time, experience tells us that is the surest way.

And we know how many thousands of dollars get wasted in here fitting parts on a guess...

[Guest]

I find it hell scary that you are such an awesome mech and you test fuel pressure with your thumb.

Because this is a subaru club swapping parts in is relatively easy but def not the best way of checking things over. Agreed if you buy parts to swap in it gets very expensive very fast if you can borrow then more power to you.

[loner]

leave it evowrx... you sound like a pc gimp...

[Eight_dollar]

 log1call said:

Well Eightdollar, after following all the subaru or any manufacturer\'s books right through, when every component including the wiring has been checked, we often find they say to fit a "known good unit". Generally that\'s only in the case of ecus though.. most other components there are specific tests for, and paths to follow to arrive at the conclusion that you should check that component.

That said, once cars have been modified, or played around with, then it rapidly becomes a guess.

I\'m a mechanic, I don\'t get paid for guesses that aren\'t right, or that are only half the fault, the victim of some other component failing... I have to be methodical, systematic, and careful, whether the car is modified or not, whether I know it\'s history or not, whether the fault seems obvious or not. I always start in much the same way.. In the long run, over time, experience tells us that is the surest way.

And we know how many thousands of dollars get wasted in here fitting parts on a guess...

The OP fault was fairly clear when you know how the ecu works to fire and run the engine

I agree that many here unfortunatly waste $$ buy doing "BLANKET diagnostic" ie start replacing parts and dont stop replacing parts until they have fixed it

I use my experience to save people $$ - being logical, systematic and having product knowledge

There are many shortcuts tho once you fully understand the Subaru systems