Hey, I have a 97 JDM WRX. Only mod is an exhaust, still have cats. My car starts and idles fine, but when driven black smoke comes out of the exhaust and the revs drop to about 1000rpm and will not got higher. My car has been at a Subaru dealer for a week now and they still can't figure it out.

I've replaced - plugs, MAF sensor, fuel pump and fuel filter.

Advice would be appreciated.

Thanks.

 

vaccum line split or not connected on manifold etc..

 

Thanks allot mate, I'll get that checked first thing tom...

 

I'll second what Simon says, check hoses from turbo to intercooler to manifold.

 

Does your engine light come on??

 

Thanks for the help, the check engine light does not come on. The turbo and intercooler hoses seem fine. The mechanics do not know what else it could be. I'm missing my scooby so much and it doesn't look like I'll even have it back for the weekend!

 

Split intercooler hose, coil packs goosed! Sounds like its running ritch hence the black smoke!

 

Thanks again,

I got Subaru to check the coil pack and the HT leads and they looked fine. They're checking all hoses today, so hopefully it'l be ready soon.

 

Got my car back today after Subaru having it for 10 days! Anyway, on the way home not even 500m down the road I had the same problem. They say it is not hoses, plugs, leads, coil, because it would not run properly the whole time which it doesn't!!! While driving the revs just drop and will not go up, if I try accelerate lots of black smoke comes out of the exhaust. Any other suggestions? I'm taking it to an X Subaru mechanic on Monday, hopefully he'l do better than Subaru!

 

Couldn't drive my car at all this weekend, but I managed to give it a good clean. I noticed a drop of oil where my car had been parked, so I checked under my car and found a leak. This is the first time the car has leaked. Could this leak be causing my power loss problems?

Thanks.

 

I picked my car up yesterday, after a few replaced/re-fitted parts and it worked fine untill 11:30 last night when the same problem started all over again.

When it went in the guy suggested it may be my head gasket and that I must check for oil leaks on a regular basis. They carried out the following:

- removed radiator & front covers
- Removed intercooler, cleaned blocked cooler, flushed & re-fitted
- Remove pulleys, cambelt etc...
- Remove and replace crankshaft (front) oil seal.
- Assemble cambelt & pulleys & set cam timing.
- Fill with coolent & bleed radiator.

The thing is if it were the head gasket, would the problem not happen the whole time I drive. If it happens, I turn the car off and restart it and its fine below boost. Boosting is out of the question.

 

ummmmm i am not sure if the head gasket can present that symptons.

If you said the CE light didnt flash maybe the ECU is bad. i have read that you have checked and replaced a lot of parts so, try to swap your ecu for another one that you are sure is ok.

Check if the Chek engine light flashes and if the problem continues.

the black smoke means too much rich A/F ratio. And it sounds to me an electronic problem.

Hope your car will be fine soon.

LG

 

I was wondering about the ECU as well for it to be behaving like this at such low revs something is very wrong but because it's black smoke not blue or white steam it hopefully won't be overly serious as black is caused by rich mix rather than knackered head gaskets/broken rings/piston etc.

I've had a similar thing before but it would still rev but just be gutless and it was caused by a split hose, but because yours won't rev at all I'd say there's an electronic issue like a wire fault or the ecu itself somehow. Just odd that there's no CEL....

 

have to agree with one of the posts above, sounds like electrics..hard to find faults if they are not there all the time thats the problem. deff getting to much fuel causing black smoke and engine to flood hence no power, revs drop

 

Thanks very much, appreciate the replies. Got it going in on Monday, so hopefully it’ll get sorted out soon. I’ll keep this thread updated.

 

Look at the obvious signs mate. Black smoke.... petrol doesnt burn with black smoke, you must be getting oil into cylinders or exhaust from somewhere. It would seem as you have tried everything that is easy, now try difficult stuff. Check cylinders for correct compression pressure and go from there.

 

Just to add something that may help but not sure if your car has a TPS, throttle position sensor but this may be goosed. If these fail the car is almost blind to how much throttle is being appiled and the fuelling will be all over the place.


AllanB

 

ECU temp sensor is worth looking at too, if its duff the ECU can think the engine is still cold bunging in loads of fuel and the wrong advance settings.

 

Hi again, I finally got my car back! It now runs alright, except for the fact that is sometimes mis-fires, usually when I'm cruising around 120kms per hr. and I push the accelerator flat. It does it once and is fine after that...? At high boost it also makes a bit of a humming sound (in the engine) then goes away, anyone know what this could be?

Its very strange that the car is going again as nothing else was done. The garage I sent it to connected a fuel pressure regulator and that seems to have sorted the black smoke and idling problem out.