ben5141

I've got an issue with my 95 STI V2 555 producing black smoke especially from cold with I'm told by people that have the misfortune of following me a strong smell of petrol. It's running standard apart from a decat down pipe & 3" exhaust system & a H&S uppipe. Any ideas of where I should be looking to try & sort this? It's running standard 4 plug ECU that can't be re-mapped.

nowellyboy

iTrader: (2)

Check your intercooler hoses for splits mate, it could be causing the car to overfuel with all the air/fuel mixtures being all over the shop. When I took my car for mapping I saw black smoke exiting the exhaust during the mapping process due to a split intercooler pipe, they replaced it carried on then the smoke issue disappeared. Just a thought mate.
Hope you get it sorted.

RedScoob

Has it always done this? It's possible that the mods are not compatible with the standard ECU.

ben5141

I'm changing the clutch next week so will give all the pipe's from the intercooler a good check over. Yeah, it always seem's to have a run rich but seems to have got worse recently.

PeeVee

iTrader: (1)

Fitting a De-Cat DP & modified Up-Pipe would not cause the standard ECU fitted to a VerII Sti to over fuel to the point of smoking.. There is a fundamental problem somewhere with either a sensor or the pipework...

Does you engine management light ever come on?.. Have you carried out a check to see if there are any fault codes stored in the ECU? You can do this yourself by following the instructions here ( http://www.scoobypedia.co.uk/index.p...eadingECUCodes ) If you carry out this check and find various codes logged in the memory, you would do well to follow the instructions and manually clear the memory, go for a drive and see what code/codes return, as these will be current faults and not ones stored from a previous problem.

Is black smoke the only problem you have?... Does she run fine apart from that?

Over fueling can be caused by various things, but before you start spending money on sensors etc, you first need to check that the air intake pipe leading from the air flow meter to the turbo & then on from there to the intercooler & on to the inlet manifold are correctly fitted and free from air leaks...

If there are no air leaks then the chances are that you have a faulty sensor somewhere.. The favorites would be one of the following: Airflow Meter, Lambda Sensor or Coolant Temp Sensor as they are the ones that have a direct affect on how much fuel the ECU "decides" to inject into the engine at any given time (if one of these goes down then the system fail safe is to inject too much fuel, as injecting too little is dangerous to the engine). The other major sensors fitted, (cam, crank & knock sensors) have a direct effect on the ignition timing & would not cause your smoking problem, so you can disregard these.

The only other reason I can think of for over fueling would be a leak on one of the internal injector seals, allowing un metered fuel to by pass the injector straight into the cylinder, but unless you have disturbed these recently this is very unlikely .

ben5141

Wow Pee Vee, thanks for going to the trouble of writing that very detailed thread. The car does run rough when cold but runs very nicely when warm (does pop & bang a bit from 1st - 2nd & 2nd - 3rd). I have quite recently had the engine out (twice), changed the HG's once as it was mixing oil & water & again when this didn't fix it, changed bottom ends over with another I had that I knew was O.K & this fixed the issue. Having said all this I didn't mess with the injectors although obviously I had to remove the Inlet manifold. The car did have these issue's before the HG issue's before & It's continued, I did notice a split in the inlet turbo hose which feeds the airfilter (best way I could describe it) thought I'd fixed it with a jubilee clip but it could well be still leaking so I'll source a decent replacement & give it a try whilst checking all the other pipes for leaks. Thanks again. P.S, it's not running any fault codes, I reset them the other day when I had to replace a faulty knock sensor.

360ste

iTrader: (1)

As said check for any leaks between the turbo and cylinder heads. If the leak is in the pipework before the turbo then this would cause a weak mixture not a weak mixture. Only after the turbo will you get air leaking out from the inlet track as the air is above atmospheric pressure. If the injectors are dirty internally then this could be stopping the injectors sealing properly so allowing fuel to leak pass. Also if the injectors are dirty this can cause the spray pattern from the injector to be more of a jet than a spray resulting in poor combustion.

Andy Stevens

Your ECU can be remapped.

www.enduringsolutions.com/InfoSheet.pdf