98 mitzi l200 2.8 l eng 4M40

Grey / white smoke is steam which means you are burning water.

White smoke, steam
Blue smoke, oil
Black smoke, rich fuel

With diagnostics failed, probably time to scrap it.

what smokes. we are blind here.
you must stay.

1: end of tail pipe smokes
2: or, with hood up the exhaust manifold smokes due to oil we dropped there. (common on much service)
and what color is it.?
from where.?
tail pipe can do 3 colors
white goes away fast ,called steam.
white stays way too long called burned oil smoke,
and black (unburned fuel) and smells like gas..

what color is the smoke? Blue tint would be fuel black is oil white is water. It sounds like the head gasket is blown to me. Pull the oil dipstick if it milky or theres milky under the radiator cap then its a head problem.

Be sure that smoke isn't steam . It makes a difference. If it smokes all the time the piston rings are worn out. If it smokes only after idling then stops soon after accelerating then the valve stem seals are worn out. If it turns out that that white smoke is really steam then the engine is burning water. A bad head gasket is usually the culprit.

Heavy white smoke is unburned fuel/poor combustion/defective injector/low cylinder compression/ pump timing off, on a diesel.

all engines do cold. its water vapor and or the hot exhaust, causing the air, to change dew point, (looks like steam)
on the white smoke smells like burned oil , it is, and is slow to dissipate like steam, (see moms tea pot , and steam fast dissipation?)

if it is oil , its most likely bad valve guides and seals, or both.
if a compression leak down test passes, its not rings, (mostly)

Black smoke is excess carbon, blue smoke is oil burning, white smoke is water/steam. Is your coolant level ok?

I would check you're fuel and return lines.ford sells a kit with all new hosesand fittings

http://www.delicaclub.com/load.php?id=20

Install the egr mod, will stop it smoking in no time
Delica owner...

first question is it smoke or steam ? if if ligers in the air behind you as you drive with little dissipation or if its steam it will dissapear more quickly . either way , head gasket is first . once saw a car do that excessive engine oil put in by owner . giant flumes of white smoke . if you ever want a true smoke scren to get away then adding about 2 to 4 quarts of oil extra . man it is something to see