Running rich when engine is cold? What is wrong?

[EagleTalonTim]

hey everyone again! I have been dealing with this problem ever since I got my car and I need to know what is wrong. In the mornings, or if I let my car cool down then start it, it pours out black smoke from the exhaust even if i am not in boost. You can't really notice the black smoke when sitting at idle but as soon as I hit the gas, it is nothing but black smoke. As soon as it worms up, it runs perfectly fine. On occasion i can notice a little black smoke when at WOT from a dead stop.

I am running 93 octane from BP ever since I bought the car.
I replaced the ECT about 2 weeks ago.
The O2 was replaced about 1 month ago.
I have no way to adjust fuel trims.
The injectors run about 85 to 95% when at WOT
The O2 reads around 0.05 to 0.78 when driving around.
No CEL.
No codes.
Running 14psi on a 13b with 450 injectors with a 92 M/T ECU in my auto.


What is causing this?

 

[canadiandsm11]

I think that can be due from leaky valve stem seals. When the car sits, oil pours down past them and once you step on it, it all gets burned away. Could also be turbo seals. Maybe someone can confirm/deny this

 

[EagleTalonTim]

i thought black smoke was rich and white/bluish smoke was oil. the exhaust is burning black.

 

[tqmx1]

It sounds like your water temp sensor is taking a dump or the wireing has come loose. It's the 2 spade unit on the base of the thermostat housing.

 

[the rage]

Are you still running a cat? Does water drip out from it? How are your injectors, they maybe leaking after shout down that will cause you to run rick at start up and when motor cools down. try some cleaner or take to a shop where they can pressure clean.

 

[EagleTalonTim]

the ECT is brand new and there is no longer a code for it when i hook up my logger. I have eliminated the cat and I am about to replace my injectors with other ones in about an hour.

 

[drewvr4]

Black smoke is def. fuel.

I might suggest first doing a compression test, then make sure all cylinders are firing. Its possible you might have a dead cylinder or a spark plug.

 

[kenamond]

Have you boost leak tested recently? How's your compression? Did you install used 450s when you upgraded to M/T ECU and did you have them serviced before install? Any misfire issues when cold? What plugs, how old are they, what gap, do any look worse than other cylinders? How old are the plug wires?

I don't know what's causing it, but it might be boost leaks, sticking injectors, a fuel pressure issue, bad spark in a cylinder or two, etc. You get to start eliminating possibilities or even fixing numerous problems that are combining to give these symptoms.

 

[mach4g63t]

It sounds like your water temp sensor is taking a dump or the wireing has come loose. It's the 2 spade unit on the base of the thermostat housing.

Yeaup. He's right. It's the water temp sensor, most likely. My car was doing this last week when I disconnected it and didn't realize that one of the wires broke. I repaired the wire, the engine starts up fine when cold now and won't stutter when trying to get moving while cold. It's the botton one on the left of the thermostat as you're looking at it from under the hood. Make sure the wire is connected or just buy another one.

 

[tqmx1]

Ok you say the temp probe is good so it's giving the extra fuel that means you are not getting the extea air. The FAIV is stuck closed in the normal run position. When every thing warms up and the temp sensor cuts back on the fuel it all returns to normal.

Change the FAIV or just the compleat TB.

 

[EagleTalonTim]

the car starts up and runs perfectly fine in the morning. There is no miss in any cylinder. The plugs and wires are about 1.5 months old. I am running the bpr63s. The wires going to the ECT are not broken or frayed. What is the FAIV? is that the IAC? If so, i have tried 2 different onces and they still don't affect anything. when the car is cold, it idles around 1400 to 1500 till it is warm, then it idles at 800 +- 50

 

[mach4g63t]

The car idles like that because it's warming up. Mine does that, as does all of my buddies
(3 other cars). Doesn't the ECU run lots of fuel when starting to make the motor come to temp? It stays in open loop mode or something until the vehicle is warm? Any one know what I'm talking about?

 

[throwedgsx]

Yeah i do. It's in the warm-up enrichments which causes it to idle higher and dump more fuel into it. Which is perfectly normal

 

[steve]

Running 14psi on a 13b with 450 injectors with a 92 M/T ECU in my auto.

What is causing this?

Get the FPR from a manual car. The injectors are flowing about 10% more fuel than the ECU thinks they should due to the higher base fuel pressure that the automatics use.

 

[EagleTalonTim]

ok, thanks. will get one as soon as i get a new transmission anyone have one for a 94 and under AWD? Broke an axle and it hit the case

 

[1bad91tsi]

ok, thanks. will get one as soon as i get a new transmission anyone have one for a 94 and under AWD? Broke an axle and it hit the case

ouch!