black smoke?!?!?

[85chevydimeinblue]

ok heres the deal i dont have my throttle posistioner and i have a feeling my map sensor is burnt out im not exactly sure any help would be greatly appreachiat the help and i do need to buy a nother tps sense mine broke i jus didnt have the money at the time

[rv34]

um..huh?

[85chevydimeinblue]

heres the situation for them non auto newbs
my truck is an 85 with the iron duke equipped with a/c just doesnt have the compressor on my truck hhas been hell to me wich explains i had to replace the head gasket and the cylinder walls looked clean when it was tore down to the block i did have to recoil(helicoil) the far right back bolt and it went together like a breeze just had to use so bars leak seal because the guy i bought it from broke the bolt and used heat to "try" to remove the bolt haha didnt work but when i got ahold of it it was done right then about 6 months later the egr was giving me hell it wasnt on the throttle respnse like it was and wouldnt go past 20 took it off cleand it and still had a prob. took it off and cleaned it once more decked the mating surface and grinded away gunked up gasket i did use gfasket sealer along with the gasket to improve my seal also my bolts did strip so i just ran a bolt and nut the the intake of were my egr is to ensure a tight fit then ran like a beauty but my throttle posistion sensor broke off litterally and i do have the money now and i do have reasons to believe thats why i have a deisal looks exhaust but a gasoline motor with black smoke like crazy but it is suttle and only when you get on the gas around the 2500 to 4000 range also ita an automatic with new altenator

does that help yall??with my problem?

[lesterl]

REPLACE THE TPS, then check back.

[85chevydimeinblue]

i replaced the tps and it is still smoking with a bit of liquid dicharge that is also black my egr was carbonized could my egr be bad?

[Shaddix]

First, learn how to type. Second, try a different MAP sensor considering its one of the most important sensors, as is the CTS sensor on the coolant neck. Third, unhook the Vacuum line going from the egr solenoid to the egr valve and leave it unplugged. Get your engine running healthy, and figure out if its EGR related afterwards.

Do not forget to post back what fixes it, as it helps people years down the road on Google cache!

[lesterl]

What does the spray pattern look like from the fuel injector? Is it dribbling? How about the FPR?

The CTS could be reading way COLD and the mix is rich.

Could be you have alot of carbon in your system that is being flushed out by a normal byproduct of combustion - water vapor.... Does it run decent now?

[85chevydimeinblue]

yea more decent i do have more off the line power and the black smoke has gone away after i took the battery cables off for a min. or two to let the ecm reset its self and bam went away and runs a solid 130 degrees with no t stat wich im going to get a 180

[lesterl]

Good Idea, I like running a 180 on older motors to keep the rubber from going bad.

[85chevydimeinblue]

yea its like shooting your self in the foot to run hotter than that because im not to sure on how many more miles before my bottom end goes out i did do a top end but that was it

[Steady Eddie]

The "real" reason to run a 180* t-stat is to keep the timing as advanced as possible, the reduction of heat in the engine bay is a sideshow benefit.

The Iron Duke has no "knock sensor" like the later engines do, but the engine dynamics are the same.

It backs off the timing based upon heat sensors and can retard the timing, some say as much as 20 degrees, to reduce knock and ping.

ANY retardation in timing affects (reduces) power and economy.

At 212* F. (100* C.) on the coolant temperature, the PCM will begin to retard the spark (timing) tables. It is a linear function: More heat above 212*, it retards the timing more.

Let's use my own Iron Duke as a test mule.

Using my Fluke IR heat gun, with the engine at hot idle, my OE 195* t-stat was controlling at 205* F. This is within test specs for a t-stat of plus or minus 10* F. and is quite "normal". This 205* reading was taken with the IR gun aimed right at the t-stat housing.

The reading was too close to the timing retard point of 212*, being just under the retard set point. It left me with a 7* "cushion" before the timing begins to be retarded.

On any long grade, uphill, or in stop and go traffic, on a hot day, that 7* cushion will vanish.
It won't boil over because of the anti-freeze in the coolant water, and the fact that it is a pressurized system, so you'd never know it was happening. But, you can feel the reduction of power, using the old Butt Dyno.

This is a built-in electronic problem, and can be solved mechanically, by the addition of a 180* F. t-stat.

But do not go out and buy a 180* F. t-stat and *just* stick it in your Iron Duke. Test it first, in a pan of water on the kitchen stove, using a kitchen thermometer, you want it to operate smoothly and NOT snap open and/or shut. New t-stats have been known to be bad, right out of the box.

After the t-stat install, my Duke runs cool, tight, and STRONG, with full timing advance. It pulls so hard, up through the gears, that I actually fear for the old 5-speed...

[85chevydimeinblue]

im going to go with a 180 t stat but im getting my black smoke still but not as bad and im not sure on how to pin hole a and b on the diagnostics port to give me a code and after it warms up to about 130-140 (i have no t stat) it starts to smoke white.could it be my rings?and valve seats?

[lesterl]

White is water man.