why is my damn car not going (again!)

[zarnah]

will have a look in the morning but as said its not the ecu at fault as have tried several spare good ecus I have and no change, so unless its getting no power it wont be the ecu but will check for power in tommorow. Anyone got the pin-out diagram they can post up?

[4ORGD]

iv also got a similar problem.the other night i was driving a 1993 f/l vz legacy wagon and it was raining as i took of at the lights on a up hill the front wheels skided and the car suddenly shut off,its dosent crank but tries to.its done close to 200km would anyone no what that problem is

[Guest]

inertia switch? I remeber under hard jandle in my old rover the vibration from the acceleration caused the swith to be set off and then it wouldnt spark or prime the fuel pump. thats just a stab in the dark , but worth checking as its free to reset.lol

[Guest]

oh and the car also died without warning too. just like yours.

[zarnah]

inertia switch? where do i find that and how do you reset it?

[Guest]

Your timing belt could have jumped some teeth if the guy that did your cambelt didn't replace the tensoiner, this fault won't bring up any fault codes and should be easy to pick up if you can remove the front covers. The second generation hydraulic tensioners are crap.

[zarnah]

still doesnt explain why the fuel pump doesnt fire up and the ignition isnt sparking.... have checked though and belt seems fine. interested in finding out about this inertia switch...??

[Guest]

Check the power supply to the fuel pump if its not working.

[zarnah]

ok will check that tommorow, it isnt getting spark either the car has been sitting for three days and have tried to start it numerous times, and fuel pressure guage is still reading 43psi (about what it should be reading) so the fuel system is still primed, obviously injectors are not working when I try to start car or the fuel system would lose its prime

[Flash]

From memory (10 years ago) The ignition relay supplys power to the ignition system and fuel pump, this was an orange relay mounted high up under the dash on the drivers side- this used to give problems. you can bridge it out & then try starting the car. it might be mounted under your bonnet on your car any way wont take long to find.

-Relays get old and burn out & on older cars pre-canbus there will be no fault codes.

-but first you need to check battery voltage-no volts nothing will go

-are the terminals tight?

-Alternators can die & then this will kill your battery.

-Always check fuses as well because it might be that simple.

-If you say no spark & fuel no fault codes. That meens it has to be a fault common to both. You always need to keep it simple & check you powers & earths first.

Also make sure all the plug connections are correctly fitted.

[log1call]

The fuel pump only gets power if the ecu tells the fuel pump relay to turn on. The relay has it's own fuse and power supply.

The ecu has some power(two I think)wires that have power all the time the battery is connected. The ecu uses those two powers to turn on the main relay. The main relay has two sets of contacts and it feeds more power to the ecu and to the ignition or injectors... I can't remember which and can't be bothered looking it up at the moment. The main relay has it's own power feed and fuse.

You can ignore, in fact you must ignore, the no fuel pump and no injector/ignition untill you know the power supply side of the circuits are working.

[Guest]

have you checked plug that's under the back seat on drivers syd?

[zarnah]

ok well checked the fuel pump today and one of the wires feeding it has power to it yet the pump isnt going, I presume because the fuel system is already primed? still dont know why I have no spark?

[log1call]

How did you check that?

The fuel pump isn't meant to have power to it normally. It only gets power for about two seconds then it's turned off again. Are you sure you had power? Perhaps the relay is stuck on?

[zarnah]

I'd say it was power to the fuel level sender as it was only one wire

[log1call]

You need to get the workshop manual, and more specificaly the pin-out diagram for your exact model and check that there is twelve volts to all the pins there are meant to be powered.

There might be a manual here... http://www.main.experiencetherave.com/subaru_manual_scans/FSM_Scans/

or here... http://www.northursalia.com/modifications/misc/wiring/wiring.html

But you need to check they are exactly the same, right down to the colour of the wires and even the colour of ecu's plugs.

[Guest]

Ring an auto sparky. theyll know where to find the switch , to reset them you just push the button on the top of it. im pretty sure thats what will be causing you these problems aye.

[Koom]

Here's an ECU pinout that has the Early RS ECU pinouts on it.

Just ignore the colours as I did that for doing single turbo conversions on BG5a's.

Make sure you use the pinouts in the bordered boxes as those are the BC5 ones.

[log1call]

Well done Koom. There you go Matty, now you need to sus out a diagram of which plug and pin is which. It looks like that has five powers into the ecu.

[4ORGD]

was that in a subaru matty? i found a forum saying subarus dont have inertia switches only fords? cheers

[Guest dynofiend]

Can I be a bit basic here, and say that it might be easier, rather than checking ECU pin outs, to just test all the obvious stuff. I mean, in theory, if the engine has fuel, spark, and compression, then it will run. It obviously doesnt have all of these at the moment, so find out which ones it does have. Pop out your fuel line and check it has fuel coming through it from the pump. Check your spark plugs are sparking. Do a compression check.

I think youve said you have no spark. Well check what causes that, first coil pack power supply, second any immboilser you have fitted, third your crank sensor (assuming the car has one [not too familiar with subs at the moment!). Once youve ruled out all those basic things (my suspicion is with your alarm/immobiliser btw) then its time to get detailed with the multitester

[log1call]

The trouble there is that you need to check that the signals are getting all the way through to the ecu, so you end up under the dash looking at the ecu anyway, and, since in this case all the symptoms point to no power at the ecu, it's the first place to go to and the first thing to check is for power. You do use a digital meter to check the power but that is the same tool you use to check the sensors anyway, so the technical expertise/difficulty is no greater.

[log1call]

Have a look here....

http://cid-4ca3c3459aaa7f7f.skydrive.live.com/browse.aspx/.Public?uc=1

there are some good tips and advice from subaru in a pdf document called "Diagnostic Aids For".

[dubbedup]

Zarnah what was this problem and how did you fix it

(apologies for reviving an old thread)

[zarnah]

It ended up that the imobiliser had set off so thats why it had no spark, the problem that had started it all was that when i set up my split rails i made some pushlock fittings up that just bolted to the end of my fuel rails with an o-ring sandwiched in between to seal them, after pulling the whole damn engine to bits i discovered one of the o-rings had popped into the fuel rail causing a nice big blockage! Thus leading to me trying to start it so much the imobiliser went off too, lol