Black Smoke

You have to get someone to check the electronics for you.

Incorrect sensors, connection, CPU or settings will play some funny tricks on you.

You would normally also have to drive around before the ¨computer¨ can recalibrate and fine tune your car.

I just had my battery replaced on a Camry and I had to drive 23km before it was running smoothly again.

If that car has the 6 cylinder engine, check for a vacuum leak at the intake manifold gasket #1 runner. Spray a bit of carb cleaner or water at the number 1 runner while the engine is running. If the car stumbles a bit then the gasket is leaking, common problem.

This leaking un-metered air will be sensed by the O2 sensor and will in turn cause the fuel injection computer to add fuel resulting in a rich running car.

Good luck

I followed your advice and quite enjoyed myself. I am pretty convinced there is no suction anywhere which is good to know Thank You

Really no "adjustments" to be made; you need to have a proper diagnosis made by a qualified technician.

What can this consist of? well...

On board computer system: codes, complete data scan and analysis, good wiring, good sensors and output devices (O2 sensor, mass airflow, temp, etc), proper charging system operation, ensure proper inputs to, and outputs from the ECM.

Fuel system: proper fuel pressure, correct and good fuel filter, proper control of fuel injectors (relates to ECM), good injectors (no leaking injectors, for example).

Ignition: Proper timing, all parts good, correct input/output voltages.

General engine mechanical condition: vacuum leaks, proper EGR (if equipped) overall good engine condition.

Lots to check, but a good shop should have a proper menu to work from for diagnosis.

Your other post regarding voltage issues with your car radio suggest there may be a voltage issue that is also affecting your engine computer and or sensors.

Better have your alternator checked.

There is a list dealing only with volvo cars that may have useful answers.

Its called Bricks.

Try this site it has an online repair manuel .

http://www.vcoa.org/700-900-faq/960_90Info.html#960SparkPlugRemoval

http://www.vcoa.org/700-900-faq/FAQSummary1.html

Your references are very usefull. Thank you

Sounds like it's over-fueling, last time I had this problem on a car it turned out to be a faulty temperature sensor, cheap & easy to replace but, as suggested in the earlier posts, it took the diagnostic kit to find it.

Lets see, you bought a car that smokes like a chimney and has a stereo that shuts down in 10 seconds or so... You didn't buy a Volvo, you bought a lemon.

If posts 4 and 5 don't get you on the right track, I would suggest that you get an inexpensive computer trouble code reader. The computer does a decent job of keeping an eye on itself.Take advantage of that. Just in case, have you checked your air filter?

Where did the car come from? It may have been adjusted for high altitude.

A rich condition can be caused by a dirty mass airflow sensor. It thinks the volume of air is greater than actual, then tells the computer to feed more fuel. However when this happens the pre catalyst O2 sensor will pick-up the unburned hydrocarbons and tell the computer to lean out. This contradicting information should let the computer know that something isn't right and a code will be thrown.

However not all vehicles have a pre catalyst O2 sensor. The ones that don't will not likely throw a code if the MAF is dirty. In this case, the rich condition will kill the catalyst. An engine running really rich will cause your converter to turn a nice glowing orange. Hope nothing combustible is nearby if that happens.

Sounds right to me

Clean the MAF situated in the intake would be a good start I dont think that a Volvo of this age has very sophisticated engine management system. Then you could check out the rest.

Many of these posts are helpful, and yes, there may be multiple factors, or multiple factors with one cause. You don't "adjust" the fuel injection, because the array of sensors in your vehicle should be doing that automatically.

Basics-

Black smoke is indicative of raw unburned fuel.

Grey / blue smoke-oil

You can ohm out whatever you like, but I am assuming your ignition system is working properly, right ? And assuming you do not have a faulty ECM you must check all relevant components for failure.

If a computer (these days there are many computers in cars) in a car gets any faulty reading usually voltage drops, or increased resistance in a circuit, it will tell the engine to compensate. But beware because certain systems are DEPENDENT ON EACH OTHER.

A faulty mass air flow sensor can mess with the mixture for example, but it can only make calculations based on temperature and barometric pressure. The volume (or density I should say) of air changes in climate and elevation, so this is a good example of why they are dependent. If one of these are faulty, you have different reactions from other sensors all the way down to the O2 sensor.

Your O2 sensor is the last defense, which analyzes the exhaust and tells the engine to compensate for either rich or lean fuel air mixture. Many times I have seen them go but sometimes they are just responding to other problems. It also depends if you have a heated O2 sensor, they go less often. And don't forget, you may have TWO O2 sensors !!

IT IS PROBABLE that with your fuel saturation now, your oxygen sensor has enough residue to interfere with its proper functionality.

Engines perform due to the symbiotic relationships of its electrical components, and it is usually one or the other that leads to total failure but always look to the components that involve fuel mixture, and above all, check ALL of your vacuum connections, from your canister, to your exhaust gas recirculation valve, Positive crankcase ventilation, etc.

I would be checking the following for sure:

All vacuum lines, Mass Air Flow, MAP sensor, O2 sensor, EGR valve, and PCV. If I think of something else I will let you know.

Thamk You Gentlemen for your advise

The car is a one owner, 15 year old, 100,000 km with body and interior like new. (Owner works for a bank and gets given a new car each 4 years) Been parked up for most of the past 10 years and all the electrical connections are badly corroded. So far I have solved all problems by putting new connectors everywhere.

Your interest and advice is much appreciated

Cornelius

NAPA markets a product called contact enhancer.

It is designed to improve the performance of any electrical connection. The product is not cheap. but it goes far. The part # is CE1. Good luck.

Change air filter

Its the O2 sensor.