scoootie5@work

I have had this problem 4 years ago and it seemed to sort itself out but now the problem is back. I hope someone can help.

Impreza MY94 WRXRA
Link ECU so no MAF or Lambda

I have been using the car all weekend with no problems at all, but when I tried to use it tonight the problem started.
I started the car it it fired up fine but I could hear some slight misfiring.
I then drove down the road and it jerked and popped out the exhaust, got to the end of the junction and it stalled. Tried to restart but would not idle it kept misfiring and stalling.
I ended up holding the throttle on with it still misfiring about 4000rpm and turned around and went back home with it popping and banging and kangerooing down the road.

Now the engines hot it will not idle but does have a few seconds where it runs fine. And I have even driven it down the road and it pulls ok when quite a bit of throttle is used.
But then it runs on 2 cylinders for a while and then clears for a second.

My first thoughts are fuel blockage or intermittent weak spark.
My FSE valve shows 3.5bar fuel pressure and I have checked all the connections under the bonnet and checked all hoses are connected.
I will pull the plugs out over the weekend and check over it properly.
No smoke or knocking noises

Any initial thoughts or anyone had the same problem???
What electrical parts can I check, do these cars have an ignitor controller?

Thanks

Scott

mr_D

iTrader: (12)

coil maybe? or leads if its not the plugs?

happydude303

iTrader: (1)

yeah id go with the coil leads and plugs renew the lot, I had this and that is what it was been fine since, if the plugs are 4 years old they well need a change and if its the original coil pack and leads change then to

scoootie5@work

I will change the plugs, but the coil packs were changed 5 years ago.
If it is the coil packs it would be wierd hat 2 go together and sometimes both work together.
What controls the coilpacks is it the ecu or is there a control box of somekind?

How long are Platinum plugs supposed to last?

Thanks
Scott

mr_D

iTrader: (12)

things is mate. i know you said coil was replaced 5years ago but thats not to say that it hasnt gone again. start with plugs first, do you now how to test the plugs to see if they are working? cos if you do try this. if you get a weak spark you could tray the plug in another lead and see what you get, if it works fine then its either the lead or the coil. put a different lead on it and see what that gives you

happydude303

iTrader: (1)

yeah and spark plugs if your car is standard and ruining the standard plugs i would change them every two years but ive been told if the car is tuned and you have the ngk 7 in there once a year at least

scoootie5@work

Right,

Today I fitted new plugs and tried swapping over the coilpacks with another set I had from a while back which caused problems at full wot. But I knew worked starting and running
They made no difference.

Went even further and checked...

Idle control valve
Main relay
Checked over all wiring for shorts and damaged wires
Checked earth and power to ECU
Disconnected my turbo timer
Continuity and voltage to injectors, coilpacks
Plugs are giving plenty of spark
And loads of fuel going in, maybe too much killing spark

Sometimes it starts fine and then dies after 2 seconds, never the same amount of time
When it starts you can keep it running by holding the throttle open but you can here it missing now and again, but as soon and you let it idle it dies.
Another times it will not start and it pops out the exhaust and sometimes bangs (backfire) when it struggles and dies.

I am now thinking either cam/crank sensor as these have never been changed
Did a resistance test on them and it showed 2.00 ohms at 20k, workshop manual says they should be 950-1250 ohms ??
Or injectors stuck, blocked or faulty (550cc) but why 3 cylinders sometimes and 2 othertimes
Or possibly ECU, Ignitor, FSE FPR

Does anyone have a working Cam/Crank sensor laying around
Or know how much one is?

Thanks
Scott