2001 Dodge Grand Caravan - Running Very Rich

[nokomisauto]

2001 Dodge Grand Caravan Sport

Van Came in flooding and hard starting and black smoke out tail pipe

Test computer no codes
Fuel presure 58 lbs at idle
Vacum at idle with engine flooding 15 in and map reads the same
Coolant temp reading shop temp at 70
Air temp at 70
plug off both evap vacum hoses
plug off egr valve to intake mainfold
Replace all six injectors with mopar parts
Tryed new map sensor
even unplug o2sensors and problem is still there
injector ms at 8.8 at idle
short trim at 24.5 %
test fuel for alcohol we only have 5% alcohol
Check for water in gas found none
Tps at close throttle .75 to .78
What I am missing or over looking
Thank You
Ray

[Tim Martin]

Short term fuel trim is that plus or minus 24.5%? Also, what is long term fuel trim number? 24.5% fuel trim either way is the maximum that the PCM can go.

[nokomisauto]

Short trims at 24.5 postive
Long trims at 0 because its not running very long

[Tim Martin]

Duh. I should a picked up on that with injector ms at 8.8 at idle. Wow. What a brain lapse.

So, we got a lean running engine, or so the PCM thinks. Based on the inputs you gave, I'd be leaning towards a faulty PCM. If I had a situation like that I think I would get out my sensor imitator and dial in a rich O2 sensor and see if the PCM responds to that.

[Gerald Martin]

We've had several of these lately with bad oxygen sensors causing a similar issue.

If it's a flex-fuel engine a failing oxygen sensor can affect the computer's calculated value of ethanol in the fuel and skew fuel trims badly.

You might try a new oxygen sensor (I recommend OEM or Denso ONLY on this specific vehicle - don't ask why) and resetting adaptive fuel memory BEFORE going to the PCM.

Gerald

[ricmorin]

Vacuum is a little low. You wouldn't have a plugged cat, would ya?

[Tim Martin]

We've had several of these lately with bad oxygen sensors causing a similar issue.

If it's a flex-fuel engine a failing oxygen sensor can affect the computer's calculated value of ethanol in the fuel and skew fuel trims badly.

You might try a new oxygen sensor (I recommend OEM or Denso ONLY on this specific vehicle - don't ask why) and resetting adaptive fuel memory BEFORE going to the PCM.

Gerald

I thought of that too but if the O2 Sensor is unplugged would't it default the values to .45 volt?

[nokomisauto]

Thanks for the help it was up stream o 2 sensor replace o2sensor and change oil and filter and fuel trims came back and flooding stopped.

Thank You
Too all imputed on this problem.