Running Rich

J

Jackjack

New Member

Aug 28, 2014

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Ky

Sep 2, 2014

#1

• Sep 2, 2014

• #1

1990 gt 5.0 replaced map,maf,coolant temp sensor,check tps.70,replaced ECM due to capacitors leaking. It has smog pump removed and tubes on back of heads are pinched and welded shut. Also replaced o2 sensors. It has headers and off road exhaust. Any help would be appreciated.

 

RacEoHolic330

I like to dress like a pretty girl

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Sep 2, 2014

#2

• Sep 2, 2014

• #2

Have you pulled codes since replacing the computer?

 

J

Jackjack

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Aug 28, 2014

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Ky

Sep 2, 2014

#3

• Sep 2, 2014

• #3

Yes and I receive 94&44 which I know is from tubes being welded shut.

 

madspeed

Colonel Mustard

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Nov 29, 1999

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a van down by the river

Sep 2, 2014

#4

• Sep 2, 2014

• #4

Ok, so how do you know its running rich? You have a wideband o2 sensor?

 

J

Jackjack

New Member

Aug 28, 2014

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Ky

Sep 2, 2014

#5

• Sep 2, 2014

• #5

I know it's running rich from mpg is 15 and it reeks of fuel from exhaust. I'm not sure if they are wide band. They are from napa. Is there diffrent types?

 

jrichker

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Sep 2, 2014

#6

• Sep 2, 2014

• #6

Did you dump the just the ignition on (KOEO ) or did you do the engine running codes (KOER) as well?

The stock O2 sensors are narrow band sensors.
Wide band O2 sensors are used in applications like Air/Fuel ratio meters and aftermarket EFI computer systems.

The stink is because of the absence of working catalytic converters. That smell is the pollutants coming out the exhaust.

The 15 MPG is about right for around town driving considering most 5.0 driver habits. It will get up to 19-22 MPG on the highway if you use the cruse control and drive 70 MPH or less.

 

J

Jackjack

New Member

Aug 28, 2014

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Ky

Sep 2, 2014

#7

• Sep 2, 2014

• #7

jrichker said:

Did you dump the just the ignition on (KOEO ) or did you do the engine running codes (KOER) as well?

The stock O2 sensors are narrow band sensors.
Wide band O2 sensors are used in applications like Air/Fuel ratio meters and aftermarket EFI computer systems.

The stink is because of the absence of working catalytic converters. That smell is the pollutants coming out the exhaust.

The 15 MPG is about right for around town driving considering most 5.0 driver habits. It will get up to 19-22 MPG on the highway if you use the cruse control and drive 70 MPH or less.

Click to expand...

 

J

Jackjack

New Member

Aug 28, 2014

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Ky

Sep 2, 2014

#8

• Sep 2, 2014

• #8

I dumped both codes to my knowledge. The ECM is not like a aftermarket chip or anything it is a factory replacement. I did find that the tps was at 1.09 and I put it to .70 seems to feel a little better. Still a bit rich smelling.

 

mikestang63

SN Certified Technician

Aug 27, 2012

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In the garage

Sep 2, 2014

#9

• Sep 2, 2014

• #9

That is because your smog equipment is off. If you still feel like checking something, unplug your vacuum line from the fuel pressure regulator and if it smells like gas then it is leaking. If it is an adjustable FPR, it should be 39psi with the line off and capped. Last, what is your timing set at. 10 is factory, most find 12-14 is the sweet spot. If your timing is off you can run rich.

 

J

Jackjack

New Member

Aug 28, 2014

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Ky

Sep 2, 2014

#10

• Sep 2, 2014

• #10

No raw fuel there but I replaced it anyhow. Timing yes it's been bumped. I'm at 12 degrees. Now one more thing to add. I started to do a compression test even though the car runs strong. I did one cylinder. It had 150psi. Which I think is good. The reason I didn't continue is because the car blows smoke after long downhill off the gas. Also it burns oil. So this winter I am going to freshen up the engine. So really the reason I am trying to figure out why it is running rich is so when I freshen the engine I don't want there to be a rich condition. Thanks for the help!!!

 

madspeed

Colonel Mustard

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a van down by the river

Sep 2, 2014

#11

• Sep 2, 2014

• #11

valve seals are shot if smoking on decel. This aint a Honda, no need for high rpm decels

 

J

Jackjack

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Aug 28, 2014

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Ky

Sep 3, 2014

#12

• Sep 3, 2014

• #12

Ok next question could leaky valve seals cause oil in the upper intake?