Jeep running rough; black smoke from tailpipe; dying occasionally

Hi there:
Black smoke is caused by excess fuel that has entered the cylinder area and cannot be burned completely. Another term for excess fuel is "running rich." Poor fuel mileage is also a common complaint when black smoke comes out of the tailpipe. Black smoke out the tailpipe is the least cause for alarm. Excess fuel will usually effect engine performance, reduce fuel economy, and produce a fuel odor.

How did the fuel get into the cylinder in the first place? Some of the causes of excess fuel are a carburetor that is out of adjustment, a faulty fuel pump, a leaky fuel injector, or a faulty engine computer or computer sensor. If black smoke is present, check the engine oil as in the white smoke example to make sure excess fuel has not contaminated it. Do not start the engine if a heavy, raw fuel smell can be detected in the engine oil. Call your mechanic and advise him of what you have found.

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signs of a bad fuel pressure regulator-- the vehicle will run rough, the engine will not start ( usually in the mornings,) many times engine starts but stalls shortly after starting. a bad regulator can result in fouled plugs. replacement is only cure. 1- black soot on plugs-2-black smoke from tailpipe-3- running rough-4- stalling, good-day! repost if need be.

white smoke.Blown HEAD GASKET/CYLINDER HEAD. BLUE SMOKE/BLACK MAJOR ENGINE PROBLEMS/ring ,valves LOtsa luck

when was the last time you gave it a tune up that is what is needing

check the O2 sensors in the exhaust manifold with a automotive meter not a code reader ,then trade it in for a diesel manual version as these are impressive but 4.7 litre gas guzler at our petrol prices about 10 dollars a gallon in the -uk and around 7/8 dollars here in spain this vehicle you couldnt give away here

Rather then actual pressures, it is better that all cylinders be within the same ballpark of each other. If 5 cylinders are around 180 lbs. of pressure and one cylinder is 140, that would indicate a problem. Perhaps you could take you vehicle to one of the major auto parts stores and have them check to see if there are stored trouble codes which might indicate whether the O2 sensor is the problem before replacing it. This is usually a free service.

Black smoke coming out of the tailpipe is a sign that your engine is flooding. Also makes it run rough.

if you are getting fire to the plgs its not the cranksaft sensor...if you arent getting fire you need to replace it they are simple to replace on the jeeps. took my son 5 minutes to change one out

Sounds like it could be a bad map sensor.
Black smoke?

What color smoke out of the tailpipe ? Black - running rich , too much fuel or not enough air . Blue smoke - burning oil , piston rings valve seales , white smoke could be two different thing's - coolant in the cylinders or fuel going stright through the cylinder out the tailpipe . No combustion .
Check engine light on ? Have you replaced plugs an plug wires ,air filter , any engine sensors - TPS - MAP - MAF etc.... How many miles on the vehicle ? 1988 model - engine worn out ?