have black smoke coming out of exhaust when starting up engine.its a diesel van?

Question

any one know what wronge. plus when turn engine off still runs for two seconds.

Answer 1

Black smoke from a diesel on start up is somewhat normal, as for the not shutting down when you turn it off, 2 seconds is not too bad, however it will need to be tuned up and have the compression checked, and see if your timing needs to be adjusted. Also see if you have too much oil in the engine.

Answer 2

A puff of black smoke at start-up is harmless. Constant black smoke says you have a restricted air stream, or maybe an injector not atomizing properly, or it is over fueling. ***White smoke means low compression and blue smoke is burning oil for the benefit of others who responded with incorrect diagnosis.

Running a few seconds after shutdown, not a problem, it takes a sec or 2 for the fuel shut off solenoid to stop the fuel flow. If it fails to stop the fuel flow THAT is a problem. You may either shut off the fuel or air to stop the engine.

In the old days the 2 cycle Detroit Diesels used an "emergency stop" flap to shut off the air flow when shutting off the fuel flow was ineffective due to a stuck injector or binding rack, then the engine becomes a "run away". Loosening a fuel filter or crimping the fuel supply line can accomplish the same things.

Occasionally a diesel may start and run backwards, creating a problem of its own- and a mad dash for the exit door by the unexperienced and sometimes the experienced but cutting off the return line again stops that. Sometimes oil is picked up in the air stream and becomes anotehr fuel source. Ether or gas fumes may also cause a problem if picked up in the air stream. But these are not concerns of this question, just remembrances of an old mechanic.

Answer 3

Check the air cleaner have injectors checked or exchange ones fitted the running after you switch it off could be the fuel injector pump the black smoke is cause by a excess fuel on the cold start that is on the injector they operate the cold starting they give excess fuel on starting from cold causing black smoke but should not black smoke after about 20 seconds of running once engine reaches normal running temp no black smoke should be coming from exhaust if it is has diesel fuel injection garage look at it if not right will fail Mot

Answer 4

I don't think it's the gasket - that would be a different colour of smoke (blue? white) and you would notice water in the oil (check under the oil filler cap for margarine-like stuff). All the rest is fair enough - change filters and check the glow plugs - cheap, quick and essential anyway. Don't waste time, just do it.

Diesel engines (which don't need sparks) can only be shut down by shutting off the fuel supply so maybe whatever does that is a bit dodgy, or maybe it just burns what's left dribbling from the line after the fuel pump shuts off.

These things could be related - is there a solenoid that shuts off the fuel flow that isn't working? If so, you could end up with unburnt fuel in the cylinders after switching off. This fuel will burn (badly, with insufficient oxygen) the next time you start up, which is guaranteed to produce black smoke.

Answer 5

Please god don't be female!!! Diesels DOOOOO Smoke when they start up..... have you ever noticed trucks with the little smoke stack on top that billow out black smoke! Don't worry... let the engine tick over for a couple of minutes and it'l clear. Diesels do not run like petrol driven cars... if you are having more than a couple of minutes smoking... take it back to the garage and ask them to check the timing!

PS. Im a female mechanic!!!!

Answer 6

I just asked my husband and he said black smoke is quite normal for a diesel.
If the van doesn't feel safe when driving , pop to the garage for a check.

Answer 7

i own a repair shop,,and most of whats happening to it sort of normal for a diesel engine to do,especially the black smoke when it starts up,,as long as it doesn't remain smoking its ok,and the 2 second run that could be a dirty injector causing it,,but i doubt it,,some of them don't die as soon as you cut the key off,,it takes that long for the fuel pump to stop working on it,,good luck,i hope this help,s.,,,PS,,lol diesel,s dont have ignition systems on them,,i thought everyone knew that.

Answer 8

it runs for a few seconds because it is called pinking..your rev counter needs adjusting and the black smoke could be you need to change your oil and oil filter or you may have trouble with your head gasket very expensive to repair. and also diesel engines produce more smoke than an unleaded car or van. i recommend taking it to a garage...hope this help.

Answer 9

Black smoke is usually diesel, but could be an ignition problem.
If it still runs for two seconds after you turn off the ignition, then it is an ignition problem.

Check it out with your mechanic.

Answer 10

It's a build up of carbon. If it's an oldish van. It's normall. if it is a lot of black think smoke. Could be the rings. Take to any machanic. And just asks. I'm sure he want bike?