Hi, i was randomly driving my 2000 Impreza 2.0 turbo AWD the other day when it just randomly cut out. I pulled over and tried to restart. it sometimes starts and sometimes doesnt. When it does start iit refuses to rev up, wont idle and sounds really really rough coughing and spluttering and popping. I changed the plugs, changed the fuel filter, made sure fuel is coming out the filter when cranking and priming, but still it wont run right if at all. Tried 3 different maf sensors all the same situation, changed the TCS still the same. Smoke tested all ok. When i spray carb/injec cleaner into the filter it runs alot better, so its almost as if the engine is being starved of fuel. Really lost for what to do next. Any ideas?
Thanks

 

Any CEL codes?
Coil pack?
FPR?
ICV?
Battery?
Earth lead?
Just a few things to consider.

 

No CEL codes, ive got spark on all 4 plugs, and wouldnt spraying carb cleaner in filter make no diff if it was the coil pack. Idle control valve has been change for a known working one. I still have standard Fuel pressure regulator on the car....is there a way of checking them... i will try source a known working one to replace and see if this makes a difference. Battery is good, holds charge and a good voltage. Have had a set of jumpleads on the engine and to soild ground points to check in case it was poor earth... still the same. Really am lost as to what to try next. Ive had the pump out to clean the bag/filter and to make sure all fuel lines are clear.

 

Have a look at the 8 pin multi plug under the bench seat on the drivers side normally white. They are prone to break up and give the symptoms you have indicated. The connector is under the rear seat on the drivers side, and is commonly covered with a thin black foam piece so it doesn't rattle, move around. Typically it's near the front of the back seat sill.

I know, it happened to me.

Or the coil pack breaking down when it gets warm.

 

I will check for the plug tomorrow when im back at the workshop. Fingers crossed it will be that as im at wits end with it. Car cant get up to temp as wont run just coughs and splutters

 

FPR can be checked with a fuel pressure gauge.
Injectors are another thing you could check,maybe one is stuck open?

 

Thanks how do i check injectors? I think a friend of mine has a tool to check fuel pressure.... what should it be? Thanks

 

3bar on idle with vac pipe off ns around 2bar with it on. Have looked to see if the vac pipe is connected ok?
Injector pulse can be checked with a decent meter.
I would check on fuel pressure 1st

 

Will check tomorrow. Thanks for your help so far.

 

more basic possiblity is the alarm could be faulty - if the car is being accidently immobilised by a faulty alarm it will mis/run out of fuel/stutter etc.

 

Similar thing happened to me a few years back and ended up being the immobiliser

 

Hi, is there a way of by passing the alarm/imob? I looked under the rear seat and only 2 plugs, both for fuel pump and sender. Gonna get pressure read on fuel rail.

 

Take the plugs apart and check the pins, they tend to corrode.

 

All seem clean and fine to me. anyone know someone thats good with these cars in the West Sussex area Pref near to BN post codes

 

Quick update, just checked cambelt thats all spot on still. going to check fuel pressure next

 

Keeping it simple,

1. Is the fuel pumpo priming, can you hear it when you turn on the ignition?
2. Take the pipe of the inlet to see if you have flow with the ignition on, put the pipe end in a jar to prevent fires .
3. Do you have flow out of the filter, take the out pipe off, ignition on etc etc.

 

Yes the pump is priming and spits out plenty of fuel from where it should go into the inlet, when cranking its the same, plenty of fuel coming out, ive taken the return off and again plenty of fuel coming out.

 

Couple of other things you can check,both have given me similar problems on my old terzo.
Fuel filler neck had corroded and was letting water into the petrol tank,easy to visually check,mine got to the point when cornering it spluttered and cut out,also left a nice puddle behind when filling up.
Also the white electrical connecting block to the fuel pump on top of the tank can be prone to melt/short out.

 

I have put £20 worth of shell v power in as tank was near empty. had the pump out the tank to clean the bag filer and plug all seemed good to me.

 

And when you can get it started up and running do you hear the pump running constantly and not cutting out? If pump was giving up or an electrical problem then you would hear the pump stop for a second or two.

 

Pump is constant when and if it starts, if it does start it is really rough and wont idle, the second you touch the throttle in the slightest it just kills it. Is there a fuel cut off switch on a classic at all???

 

Not a switch but immobiliser does cut fuel pump

 

Pump is working though so cant be imob. Is there a way of uploading videos to this site? i have a couple of vids of what its doing

 

Just uploading the vids to youtube i will copy and paste the links when uploaded

 

 

mine sounded like that for a day after I washed my engine - had to spray WD40 into the injector connectors to try and flush the water out. Been grand since, could be worth checking?

 

Just has all the plugs off the injectors one by one... had three off at one time and it sounded the same.... its running on one injector. Ive checked for fulse with a noid light (led bulb) and all are pulsing...its just not putting the fuel into the cylinders i guess.... ive had one of the non running injectors out and powered it up and its clicking so guessing its working. could 3 randomly have become blocked? Its the last injector before the return that is working in the engine if that matters

 

if you swap the working one to another spot does it still sound the same with the others disconnected?

 

I did try that and it didnt really wanna start at all or do anything just a cough every now and then. Im so confused

 

Earthing.

Given the age I'd check all earthing again, including engine earthing, for corrosion.