clouds of black smoke - no get up and go.

so, about a week ago i notice that black smoke bellows out of my jeep when i hit the the gas hard. no biggie right? just running rich, i knew the fuel pressure regulator was going out, probably finally kicked it.

im going down a side street and some guy in a mini van come up like half a foot from my rear because im going like 38 in a 45.

i motioned for him to go around but he wouldent get off my arse.

so i thougt, hrm, he wants me to speed up, ill show him what happens.

so i slam on the gas and a cloud of black smoke engulfs his little van making visibility hard i bet, and he hits his breaks hard and ducks back about 5 car lengths until he passes me as i turn at the next intersection.

to make a short story long, i could live with the smoke, everythign else looked fine and smoke of that color is un burned gas to my knowledge.

gas hits 3.82 here.

i dont drive for a week

start 'er up today and drive to work because its freezin balls.

NO acceleration - my get up and go has got up and left.

I'm pulling 3200 rpms down a vacant street and i'm getting at best 20 mph

this jeep has put me through hell since gettign it, but i have loved every minute of working on it. now if i could just get it to stay in one peice...

so, the problem is this, in sumation.

theres alot of black smoke and it runs rich.
i have no acceleration.
and its hard for me to tell but i think i might have a miss or something.

ANY help would be greatly appreciated

Trent

you'll want to verify proper ignition first as a miss will give you lack of power and cause rich exhaust. After that, your symptoms are similar to a leak or blockage in the MAP sensor vacuum line or a faulty MAP sensor. Other things to check would be internally leaking injector or two (or six!) and a faulty CTS that is always reading cold and telling the ECU to richen the mixture to compensate. I would consider an O2 sensor change after solving the problem (to know it's clean enough to work), but I don't think I've ever seen one fail and cause such a rich condition that you can "fog for mosquitoes."

How hard did you push the Jeep a week ago?

They tell me a clogged/partially clogged Cat won't cause black smoke, but mine did--a big old cloud on the Interstate. The other symptoms sound the same--you might check it out.

What year?

O2 Sensors will cause the mosquito repelling fog!!

I have had three seperate vehicles do this to me.....

Change it now before you have to buy a new cat converter. The one on our van melted down in about 10 miles.....(And then it wouldn't run do to the extreme backpressure......)

Ok, I went out to tinker with it this morning and the CAT is toast. the ceramic has even broken loose.

from the suggestions on my local 4x4 club, naxja and VJC,

it looks like i need to disconnect the cat from the exhaust down pipe

replace the O2 censors,

replace the fuel pressure regulator

check the CPS

check the MAP

pull the spark plugs

check cts - could be reading cold

check the distributor for movement/ proper timing

full tune up.


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and to answer a few questions,

My jeep is a 1989 Cherokee 4.0 4x4

all the fluids have been recently changed ( 2 weeks) and performed an engine flush at meinekee (spelling?)

it is fuel injected on the renix system

i have never replaced the cap and rotor or the wires but spark plugs were put in at mel clayton ford down in phx about a year ago.

it has had overheating problems in the past but mainly due to faulty bottle on the closed cooling system which i hope to convert later on as it hasnt been giving me any trouble lately.

the thermostat was replaced about 5 months ago by R&R Automotive here in Flagstaff

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Thankyou all for your help,

and I'll let you know what i find as i find it

Trent

well, one problem down.

no more smoke as of yet.

turns out the smoke was carbon buildup inside the cat knocking together with the high speed exhaust coming out at higher rpms

took the cat and muffler off, ran around with it off,

gained SOME power back but nothing too dramatic,

punched out all the honeycomb with a screw driver and emptied out the cat, put everything back on.

runs quiet now, but ive noticed two fluid leaks and what sounds like a bad lifter on the #1 cylinder (intermitant tap/knock)

and it still is running a bit rich.


-Trent

Running way rich for a while can destroy the cat converter. So maybe you're plugged cat is a symptom more than a cause?

Yep, running rich for too long can clogged the cat. Most likely culprit is your O2 sensor but the rest need testing as well.

How's your gas mileage been?