right bit of a long story so bare with me... my power steering pipe union stripped the thread out my steering rack, so ive paid a mate, who's a mobile mechanic to remove the rack, helicoil the thread and refit it, as ive been workin abroad, when ive come back ive had to re-fit the intercooler as i had removed it when diagnosing where all my PAS fluid had gone.

now, the engine ran before i fitted the intercooler as it had to be ran up to check the repair had worked, i use the term 'ran' very losely as the MAF wasn't connected.

after i had refitted the intercooler, it was only running on 1 cyilnder (i know this cause i disconnected 3 coil packs the engine tone didnt change, untill i disconnected the last one, at which point it stalled)

i removed a spark plug and placed it in a coil pack, againsted the inlet manifold, and i had no spark, so i checked the coilpack's live and it was ok.

i then swapped my ecu with an old 1 i had lying around at which point the engine wouldn't fire at all, so i swapped it back and it still wont fire on any cylinders

am i right in thinking that ecu uses the crank sensor signal to decide when to fire the coils, and if the sensor fails, the ecu wont fire the coils at all?

bit confused by this as nothing had been off apart from the steering rack.

any one got any sugestions?

 

First things first - what type and MY is this car? Bit of a messy situation there, there's a possibility of multiple faults, and the random factor of the third party mechanic getting you to where you are. Anyway...

You're correct in thinking that the crank (and cam) pos sensor is instrumental in the timing and initiation of the spark. However, the other part of that is that's also central in the duration and timing of fuel injection too. If you lose the position input, as well as no spark, you lose FI. So, the quickest way to crosscheck this suspicion is to look at the plugs.

If they're dry after a start attempt, you can concentrate on the position sensors. If they're wet, work backwards from the coilpack to igniter (if you have a 97-8) and then to the ECU outputs.

 

damn, yeah i ment to say what model etc i have, its a 95 V2 wrx with 4 coil packs, the plug was dry black when i removed it, if that helps?

 

just done a bit of research, is the cam & crank sensor the same type of sensor? so could i swap them see if that makes and diference? or does the ecu need a signal off both before it decides to fire the coils/injectors?

makes sense that it was running on 1 cylinder to start with (maybe 1 sensor had failed) and now it wont fire at all, maybe both sensor's have failed

cheapest place to buy the sensor? about £80 for 1 off ebay

 

I have both of the sensors ( there not the same) £40 for the pair sent by next day courier sir

 

ah right, are these new or used? for a V2 95 wrx?

 

hi mate,

it sounds like your crank and cam sensor is at fault,

but if you have an early loom your crank and cam sensor will plug in at the bulk head seperatly or is it just one connector

plugs are dry as earlys dont fuel when theres no spark

if they plug in seperatly swap them over

 

There off my 95 MY classic.......which I broke.... was running perfectly . I put the engine into a 93 shell which uses a different engine wiring loom and crank and cam sensors hense there for sale....... and this site is so slow I better leave a number you can call if you want them.... 07920 842263 .or my E mail ...... mike_mcdermott@btinternet.com

 

i think its a later loom as there's only 1 connector by the bulk head (above gearbox but below intercooler)

thanx for the advice.

 

i'm working away for the next 3 weeks mate, so ill give you a bell when i get back