The car is running ruff when at idle, driving along and you can see wifs of black smoke. Come around a corner and it back fired and left a huge black cloud. Reved the car when I got home and again it back fired and a nother huge black cloud. There is no problem with boost, I can't see or hear any leaks in the cooler pipers or cooler. It also used 1/4 tank for 25km. I'm hoping it just needs a good tune. What do you guys think....Thanx

I had the same problem, check your oxygen sensor - mine was doin last year, on a trip to perth... i had to drive back with it doin that (sitting about 160 made the car drive smooth, it was a 1500km trip) another thing to check is your leads... mine started doin it again last december, and it was that my coil lead had corroded away... replaced that, and was good again... so yeah, check your oxygen senser, and coil lead - let us know how u go.

The sole purpose of the oxygen sensor is to check the amount the oxygen in the exhaust for the cat converter to do it's job at maximum efficiency... the car will not sputter and spill black smoke and **** if not present , matter of fact , it might idle even better as the ecu does not tell the injectors to go : lean/rich lean/rich lean/rich ... I bet my money again on afm ; it is exactly what has happened to me and another 3 cars I have fixed with the same problem . cheers

The following symptoms will help tip you off to a failed oxygen sensor: Surging and/or hesitation Decline in fuel economy Unacceptable exhaust emissions Premature failure of the catalytic converter You will need the following equipment: A handheld volt meter (digital VOM) A propane enrichment device An oxygen sensor socket The manufacturer's vehicle specific test instructions. It should take less than 10 minutes to perform a diagnostic check on most vehicles. 1. Verify the basic engine parameters, per the manufacturer's specifications for the following: timing, integrity of the electrical system (supply voltage), fuel delivery mixture performance and internal mechanical considerations. 2. Treat the rich mixture performance as follows: a. Disconnect the sensor lead to the control unit. b. Run the engine at 2500 rpm. c. Artificially enrich the fuel mixture by directing propane into the intake until the engine speed drops by 200 rpm. Or, if you're working on a vehicle with electronic fuel injection, you can remove and plug the vacuum line to the fuel pressure regulator. d. If the voltmeter rapidly reads .9 volts, then the oxygen sensor is correctly sensing a rich mixture. But, if the voltmeter responds sluggishly, or if it stays below .8 volts, then the sensor should be replaced. 3. Test the lean mixture performance as follows: a. Induce a small vacuum leak. b. If the voltmeter rapidly drops to .2 volts or below in less than a second, then the oxygen sensor is correctly measuring the lean mixture. But, if the voltmeter responds sluggishly, or if it stays above .2 volts, then the sensor should be replaced. 4. Test dynamic performance as follows: a. Reconnect the sensor lead. b. Set the mixture to specification. c. Run the engine at 1500 rpm. d. The sensor output should fluctuate around .5 volts. If it doesn't, replace the sensor. Diagnosis When performing diagnostic work on your customer's vehicle to determine the cause of a driveability problem or perhaps the reason for failing an emissions test, take the opportunity to check the operation of the oxygen sensor for proper functioning. Recalling that an oxygen sensor will influence the air fuel mixture preparation only when it has reached proper operating temperature (at least 350oC), it is essential to first ensure that the engine and sensor are warm enough to allow operation in a "closed loop" condition. It may take as long as 2 1/2 minutes after cold start for proper exhaust temperature to be reached (somewhat shorter for heated-type oxygen sensors). To check the performance of the oxygen sensor, run the vehicle engine at about 2000 rpm (or at normal cruise when working with a dynamometer) to ensure that the sensor remains hot throughout the test procedure. Do not remove or disconnect the sensor lead in order to test it as this will eliminate the "closed loop" signal to the electronic control unit and result in a non-cycling voltage condition. Using a correct electrical impedance test device as found with a laboratory type oscilloscope, connect your test leads so as to read voltage from the signal wire to the electronic control unit. With vehicles that use a heated oxygen sensor (three or four wire), it may be necessary to bridge the connector leads and tap into the signal wire with an appropriate test probe at the connector plug in order to obtain the signal. The oscilloscope will allow you to read the electrical response pattern of the oxygen sensor to changing exhaust gas oxygen content as a measure of its performance. Before proceeding, be sure that you are using the correct measurement scale for your specific equipment as specified by the test equipment manufacturer. (Invariably, this will be a low voltage scale.) A properly functioning oxygen sensor will exhibit a rapidly fluctuating voltage signal alternating between approximately .2 and .8 volts in response to varying residual oxygen content in the exhaust stream. Look to your scope's time reference line for a desired lean-to-rich and rich-to-lean time of less than 300 milliseconds. A response time greater than 300ms. means that the sensor should be replaced. It is important to recall that these values are valid only when checking a sensor operating in "closed loop" in a hot exhaust stream (350o-8OOoC). Sensor age degree of contamination, mixture setting, and exhaust temperature all have an effect on response time. Without this rapid electrical response to changing exhaust composition, the control unit cannot accurately correct the fuel mixture. A sluggish sensor is either contaminated or beyond its intended service life and must be replaced. Additionally, check vehicle manufacturers' service recommendations and suggest replacement of the oxygen sensor at specified intervals. Oxygen Sensor Installation Tools In cases where installation position is difficult to access, Bosch recommends using the following tools: OTC 7189 Oxygen Sensor Wrench OR Snap-On 56150 Oxygen Sensor Wrench (Crowfoot type).

wow thanks for the replies guys. I cleaned the o2 sencor, sprayed the AFM conections with CRC. It made no difference. Put $30 of fuel in and the car is running great. However I'm now back to just over 1/4 tank and the fu*ken think is playin up again. Some original photos have not been recovered yet.

mate, what fuel do you put in your car? have you also done a self diagnostic's with the ECU?

get some new injectors dude, bet the pintles in urs a F.U.C.K.E.D and they leak like dirty little hoes. prolly solve all ur problems. Peace yall

lol exchaser had a similar problem with the cas, started idling very low, blowing black smoke, tried to give it some revs and it just backfired. i figured it was the cas not reporting the correct timing to the computer and so it was running poor. i replaced it and it fixed the problem Let us know!

i'm suprised no one has mentioned the fuel pressure regulator yet... when they go, i've heard that sometimes it dumps fuel in straight through the vacuum feed to the plenum. either way check your fuel pressure. it's running mega rich to blow black smoke.

Quote: Originally Posted by Some Bored Dude mate, what fuel do you put in your car? have you also done a self diagnostic's with the ECU? Yeah I use premium, I'll have to save so this thing can go into a turbo specilist and get fixed once and for all. CAS should be fine as it was replaced 4-5 months ago. Natho where do I find the vacuum feed? Enjectors would not be good, as cost is around $600-$700 to replace em, arnt they?