mbd sti2

iTrader: (2)

where to start, one week ago going home after work car cut out and would not start again left it an hour and it starts fine a week on and it happens again this is what happens.
Driving along in traffic at say 30mph 4th gear about 2500rpm and the rev counter drops to 0 all ignition lights come on car will crank but not fire,
next time it did it 3000rpm 40mph 4th gear rev counter drops to 0 i leave it in gear coasting clutch out (so on the over-run) and still no rev reading so you start to think cam or crank sensors (either or) but i have no fault codes, so i then think fuel pump so tonight i had my dad drive the car at 30mph in 4th gear and i unpluged the fuel pump yes the engine dies but in gear rolling the rev counter does not drop until you de-press the clutch and then the gear box is not turning the engine so the engine stops.
I have tried a cam and crank sensor of another sti v2 and same things happen its a very random fault it can go a week with no trouble or a day has any one got a clue

car is an sti v2 wagon esl live re-map 18 months ago fmic induction kit full de-cat exhaust so its basic known upgrades on a good sti wagon

but i have no fault codes at all but if i pull cam or crank sensors when its running it stalls rpm drops to 0 instant but then i get a fault code depending which one i pulled

make sense ? welcome to my world

Splitpin

There are a number of faults (or combinations of faults) that might cause what you're experiencing. First thing I'd be tempted to check is whether the power supply to the ECU is reliable.

mbd sti2

iTrader: (2)

very true i wish it would just stop and not re-start it would make it so much easier to find i will be disconecting ecu soon and testing the feeds and earths also going to put a 12v load (using a head lamp bulb) through the cam and crank sensor wiring to see if i have any poor wiring joints or damage its a hard fault to find

Biggs

iTrader: (14)

Had the same problem in my my99, turned out to be the number 10 fuse (behind the coim tray) was loose

mbd sti2

iTrader: (2)

worth a look Biggs cheers for chiping in all advise is welcome

Splitpin

Whoa there a second! Firstly don't use a headlamp bulb to check sensor wiring continuity. Knowing Subaru, the gauge of the cable and connections they've used will be sufficiently weedy, you'll melt something if you send 6+ amps through them! Only half joking too!

A headlamp bulb bears no relation to the very low currents you'd normally get running through these lines. 'Sides, as things stand, everything you know suggests that the cam and crank sensor inputs are good - if they weren't, as you've found out by unplugging them, you'd get a CEL when the engine cut.

Bigg's suggestion is a good one to follow up, as would be checking whichever relay on your car is responsible for the ECU supply. Ignition switch might be worth a look too. Sticking a multimeter into the ECU +12v and ECU ground and driving around a bit would also be a worthwhile experiment - watching for fluctuations in the voltage, especially if it starts to splutter or stall.

Bob Rawle

Could be a dry joint problem on the esl pcb, to check that unplug the ecu and open the case. Looking in at the ecu with the connector facing you will see the esl piggyback rear left, just to its right in the rear right corner you will see a zero ohm link thats been cut, carefully join that back by soldering, note do not use a high temperature tip for this.

Plug back in and drive. Be wary cos if you have significant mods you are now back on the std ecu mapping but it will show up a fault on the esl pcb beacause if its now fine then the fault is that and its probably a dry solder joint from what you have said.

cheers

bob

mbd sti2

iTrader: (2)

bump