Outer Limits 4x4 Board

Hi all, I have been a member of the forum for a while and offered some advice to people before on Gas setups since i owned one for 6 years and did all my own Gas work on her

I now have a Diesel patrol and know 3/5 of sweet FA about these engines apart from how they work.

When we got her i got my old man to rev the engine in the driveway to see if there was any access black smoke. When you rev it, nothing at all comes out of the exhaust at all.

When i was heading away camping to Woodpecker challenge i had a friend following me, asked him on the UHF when going up hill how much black smoke was comming out, he said if he didn't know i had a diesel from me telling him you would think it was a petrol engine, there was none, now i have heard you are supposed to have black smoke coming out, if i am getting none comming out does that mean i have a problem with the engine or its fuel/timing?

Black smoke means a rich mixture. Lack of black smoke means all the diesel is getting burnt in the combustion process efficiently. Diesel is the opposite of petrol, it runs hot when rich. But with diesels the more fuel you can get to burn, the more power. So a little black smoke usually means that the vehicle is close to in tune. Note i said a little!!!!, just a whisp, not a smoke screen. This is a pretty rough was to judge a vehicles tune though.

Layto....

I would have thought that free reving, under no load would have produced a fair amount of black smoke, due to the reduced cylinder temps???

Mine does anyway, i dont think it hurts for a diesel to blow a little bit of smoke, just not too much...

MyGQ wrote: now i have heard you are supposed to have black smoke coming out....

old wives tale

if its smoking then it has a problem. the only time they really make any smoke is under suden large load change eg dropping the cluth and foot to the floor, exspecially if the motor bogs a bit. the fuel simply dosn't burn that well. normall driving you should not get any.

generally i find if you poor in to much fuel (makes black smoke) you get a small increase in power but a big decrease in fuel economy.

sounds like you have a good motor.

lay80n wrote:Black smoke means a rich mixture. Lack of black smoke means all the diesel is getting burnt in the combustion process efficiently. Diesel is the opposite of petrol, it runs hot when rich. But with diesels the more fuel you can get to burn, the more power. So a little black smoke usually means that the vehicle is close to in tune. Note i said a little!!!!, just a whisp, not a smoke screen. This is a pretty rough was to judge a vehicles tune though.

Layto....

x2

Same as the others.

Though the only other time where you might get a bit of black smoke is when idling for a long time in the 1 spot.

An example would be sitting at a drive-thru.

I think the soot builds up in the exhuast and when you get going it'll be pushed out, making it look like your've got a bad diesel engine.

zookjedi wrote:

lay80n wrote:Black smoke means a rich mixture. Lack of black smoke means all the diesel is getting burnt in the combustion process efficiently. Diesel is the opposite of petrol, it runs hot when rich. But with diesels the more fuel you can get to burn, the more power. So a little black smoke usually means that the vehicle is close to in tune. Note i said a little!!!!, just a whisp, not a smoke screen. This is a pretty rough was to judge a vehicles tune though.

Layto....

x2

x3

if there is no smoke and you have power then all is very well..be happy...

thanks guys

puts my mind at ease. Very happy so far with the diesel, it doesn't have the speed that my old Petty used to have but its off road torque and crawling ability leaves my old petty for dead

Trubo b4 end of the year to give it a little bit more life up hills