I have a 1991 mitsibishi mighty max and it blows thick white smoke when I start it, why does it do that. It runs good though.

The problem may be a cam/crank position sensor that is causing this. Check that the cam shaft is turning ( broken timing belt/chain)

Hi, I own an 86 Mighty Max truck myself. Is there anyway you can get the code number for the engine light coming on. It could be many things that cause this problem. Fuel filter, EGR, Clogged Catalyst, Sparkplug Misfire, Cracked Distributor Cap, the list goes on. It needs to be determined if the problem is fuel or electrical related to help diagnose the problem.

If it is doing this only when you rev the engine after it has been idling a while, it is probably smoke from burning oil. A new set of valve stem seals will probably work wonders in reducing the smoke. Stopping the oil consumption will not only help it to pass a smog test but will also help to keep from damaging your engine and your catalytic converters. 110,000 miles is just barely broke-in for a Mitsubishi engine. However, the seals are probably cracked and broken due to the AGE of the vehicle.

two possible causes -one -the ignition module ---two -the crank sensor but this you can test but the module you cannot just change it and see and i think that this will be your problem

OIl coming up the dipstick indicates a build up of pressure in the crankcase... change the PCV valve
White smoke in the exhaust indicates water and the smell is most likely antifreeze.. Blown head gasket

This is not good. White smoke is usually coolant, but the deposits on the plugs indicates oil related issue. Major exploritory surgery is in your future.

Start with a leak down test, and based on the results of that, your next step will be more clear.

Sorry for the bad news, but you already knew that, with the smoke report.

White smoke during acceleration is usually the result of a "blown" head gasket. Antifreeze getting into the cylinder is the cause of the white smoke. Check the coolant level, if it's low you have the problem.

Check to make sure the PCV Valve is working...when you remove it from valve cover and shake it...you should hear ball inside rattling, and even though it's running ok, you might need new piston oil rings and/or valve job. In the mean time you could try products for "stop oil burning", or change your oil to a heavier weight...if you're using 10w30/40 try 20w50 and see if that helps.

could be coolant temp sensor

Does not have adjustable valves . It has hydrolic valve lasher's . they are spring loaded ( i believe ) . I just replaced them in mine . valve giude seal's where worn out causing it to smoke realy bad ( looked like a mosqito truck ) and the valves where ticking , due to the hydrolic valve lash adjuster's being worn out . They are about $ 8 - 10 buck's each at advance .