Running very rich

[Guest Jeepguy92]

Hello everyone! First time posting here with my new Reatta and looking for a second opinion. 89 Red/Tan with 177K

 

The issue I am having is (visually) the amount of black smoke coming out of my tailpipe during operation. When I start the vehicle it immediately starts chugging blackened smoke that barely clears up after it has warmed up. I also have a miss somewhere in the engine that can be heard under slight acceleration. That being said, I have ran seafoam through the intake and fuel, replaced plugs/wires, coolant temp sensor, O2 sensor, new crank pulley, and CKP, new CMP, tested coil packs with a series 2 coilpack/ICM (no change), and nothing has cleared it up. The worst part is there are NO CODES whatsoever on the CRT. I dont have a misfire code, nor any other code to help me diagnose it. 

 

Aside from throwing other parts at it, I would like to see if anyone has had the same problems with it. I have somewhat concluded that the fuel pump is not the culprit as it starts up every time and doesnt cut out under WOT. Maybe fuel pressure regulator? Catalytic converter? Something else? 

I want to be able to pass emissions and get my gas mileage back to where it should be, so thanks in advance for any info!!

[Ronnie]

Welcome to the forum. I would check the fuel pressure. Fuel Pressure Testing

[89RedDarkGrey]

Warmed engine, use CRT ECM OVERRIDE to ES09, step up the idle to 1k. Can of Brake Parts Cleaner and spray around the intake manifold, where it seats to the block, and heads. Be very careful of the exhaust- BPC is highly flammable.

 

Listen for a change in idle- an increase will mean a leak, very common problem with OEM gaskets this age. False air will tell the O2 sensor to increase the duty cycle of the injectors, making it rich.

[harry yarnell]

The O2 sendors don't come into play until the ECU goes closed loop. This guy's got rich mixture from cold startup.

[2seater]

Unplug the MAF and start car. See if that clears it up.

[89RedDarkGrey]

3 hours ago, harry yarnell said:

The O2 sendors don't come into play until the ECU goes closed loop. This guy's got rich mixture from cold startup

 

A very obvious and true statement. Being that the intake is cast aluminum, and the block is cast iron, and heads are steel- there is uneven heating until "operating temperature" is achieved for closed loop. False air (past the MAF) before closed loop would cause a lean condition- only in a preheated O2 sensor, that is artificially "awake" and can monitor and control.

 

As the engine warms- a false air leak could get worse. I'm just throwing out a suggestion what to check for- not making a definitive diagnosis.

Edited June 30, 2017 by 89RedDarkGrey (see edit history)

[Ronnie]

19 minutes ago, 89RedDarkGrey said:

False air (past the MAF) before closed loop would cause a lean condition- only in a preheated O2 sensor, that is artificially "awake" and can monitor and control.

This guy's got rich mixture from cold startup. He said, "When I start the vehicle it immediately starts chugging blackened smoke that barely clears up after it has warmed up.". I'm sure you missed that part of his post or you wouldn't be posting about what would be causing a lean mixture.

 

 

[89RedDarkGrey]

Nothing missed. Depending on the severity of intake gasket failure- when all is cold, oil and/or coolant can also be drawn into the combustion chamber- or even jump around it all together, and dump them into the (usually in our cases of engine placement) rear exhaust manifold, causing "When I start the vehicle it immediately starts chugging blackened smoke that barely clears up after it has warmed up.".

 

I advise a smoke test, engine cold and hot- to completely rule out an intake manifold leak(s).

[89RedDarkGrey]

Burning oil is only "bluish" when it's burned in the combustion chamber. If it's leaked into a cold exhaust- it will be black, like an old worn diesel.

[Guest Jeepguy92]

Oh yes, MAF is also new. I sprayed starting fluid around the intake and no leaks could be found. I doused the top of the motor, just to be sure lol. I also did a rudimentary injector balance test by unplugging the injectors one at a time and every one of them effected the idle significantly. I think an oil leak might be a good point as I do have oil leaking from the back side of the motor. Looks to be the rear valve cover but with this age/miles it could be the intake gasket leaking internally as well, but as stated above, no perceivable vacuum leaks anywhere. 

[89RedDarkGrey]

1 hour ago, Jeepguy92 said:

I also did a rudimentary injector balance test by unplugging the injectors one at a time

 

You can also do this- from the comfort of your drivers seat. Enter diagnostics, ECM OVERRIDE, ES10, UP is "Extend" DOWN is "retract" the pintle for each injector.

 

1 hour ago, Jeepguy92 said:

I sprayed starting fluid around the intake and no leaks could be found. I doused the top of the motor, just to be sure lol.

 

Creating a potentially dangerous situation by not using the advised chemical or method isn't laughable. "starting fluid" is highly explosive if it contacts a hot exhaust or an energized electrical component under the right circumstances. A spray of plain water is actually safer- but instead of increasing RPMs it will stumble the engine if drawn in by a vacuum leak.

 

1 hour ago, Jeepguy92 said:

I think an oil leak might be a good point as I do have oil leaking from the back side of the motor. Looks to be the rear valve cover but with this age/miles it could be the intake gasket leaking internally as well, but as stated above, no perceivable vacuum leaks anywhere

 

Yes, an internal vacuum leak won't be audibly noticeable. If exhaust is being drawn into an intake passage- it will act like EGR, and fool a working O2 to enrich the charge. With engine cold- place a clean white cloth over the tail pipe. Examine it- color, odor. Do again when warm, different cloth. Compare the 2.

 

This is a fault that must be remedied- or this exhaust condition will poison the catalytic converter. 

[2seater]

In the absence of a fuel pressure gauge, a couple of things can be done to see if the engine is looking for more or less fuel. First, pull the vacuum line from the fuel pressure regulator. Any trace of fuel at this connection indicates a blown diaphragm and the engine will ingest unregulated fuel through that line. Second, use the diagnostics to observe the Ed19 and Ed20 readings, this is the fuel integrator (short term) and block learn (long term). Run the engine around 1500 rpm after it has warmed up, and observe the two readings. The target value is around 128, and if it is substantially higher than that, the ECM is adding fuel, if lower, it is subtracting fuel. As long as you are in the area already, observe Ed18, which is O2 cross counts to see if the oxygen sensor is active and controlling the fueling.

[padgett]

First check all fluid levels to see what it is burning (something should be low or dropping).

 

If the diaphragm in the vacuum modulator on the transmission ruptures it will smoke badly and may foul pugs but will not use any oil. Transmission fluid in the vacuum line is a symptom.

 

I would also use the diagnostics to check the ECM coolant temperature AFAIR this is a different sensor than displayed on the dash (can someone verify ?) Very low sensor can cause an over rich mixture.

 

ps there is also a closed loop delay (longer for cold startup than warm). Smoke immediately is something else. Also enough through the exhaust will clog the CC.

Edited June 30, 2017 by padgett (see edit history)

[Guest Jeepguy92]

Ignore the rattling sound, this turned out to be the tone ring on the back of the harmonic balancer, which is why the balancer and CKP are both new. I'll try to get data when I can 

20170625_185920.mp4

[89RedDarkGrey]

Why is there visible black smoke coming from the top of the EGR? I would now definitely smoke test this engine. I believe you have an EGR or internal exhaust leak (intake gasket)

 

There are many DIY videos, on the fabrication and usage of an engine smoker, and how to use. Mine cost about $20 to build.

 

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[Guest Jeepguy92]

That would be the rear valve cover leaking oil on the exhaust, not gonna put that off forever but I just haven't gotten to it yet. 

[89RedDarkGrey]

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[D-a-n-i-e-l]

What about your spark plugs? When was the last time they were changed?

I have only seen them cause black smoke on a lawn mower, but it may be worth a check.