2001 running rich, no power, poor MPG’s

[Kesh2011]

2001 running rich, no power, poor MPG’s,rough idle

New member here. I have a 2001 3.0 automatic 4x4 with 180k on the odometer. I’ve had the truck for several years and it never has really run right. I have treated the engine with seafoam, Clean the mass airflow sensor, and I went to change the plugs expecting them to be fouled but found them to be in pretty good shape. They were a nice tan color. They did not look like fouled plugs indicating a rich running motor. Instead of changing them I cleaned and gapped them because I may treat the motor with seafoam again. As the title says the truck has no power and only gets nine or 10 miles per gallon. I expected the plugs to be fouled but was surprised to see that they were not. I also replaced the coil pack about a year ago because I had a misfire codes on the scanner at NAPA. So my question is if the truck is running rich and is getting bad gas mileage why wouldnt the plugs be fouled? The truck does run a little better after the work I have done to it. I filled it up again and will be checking in. Any help would be appreciated.

 

[gungfudan]

New member here. I have a 2001 3.0 automatic 4x4 with 180k on the odometer. I’ve had the truck for several years and it never has really run right. I have treated the engine with seafoam, Clean the mass airflow sensor, and I went to change the plugs expecting them to be fouled but found them to be in pretty good shape. They were a nice tan color. They did not look like fouled plugs indicating a rich running motor. Instead of changing them I cleaned and gapped them because I may treat the motor with seafoam again. As the title says the truck has no power and only gets nine or 10 miles per gallon. I expected the plugs to be fouled but was surprised to see that they were not. I also replaced the coil pack about a year ago because I had a misfire codes on the scanner at NAPA. So my question is if the truck is running rich and is getting bad gas mileage why wouldnt the plugs be fouled? The truck does run a little better after the work I have done to it. I filled it up again and will be checking in. Any help would be appreciated.

What grade Gas are you running?

 

[Kesh2011]

85 octane

 

[alwaysFlOoReD]

Any codes? In memory?

 

[Kesh2011]

P0300, p1684

 

[alwaysFlOoReD]

P0300 Random/Multiple Cylinder Misfire Detected

P1684 Metering Oil Pump Position Sensor Circuit

P0300 seems to be the culprit for the rich running. It makes sense for clean plugs because there isn't just one cylinder running rich, so the plugs stay clean. I don't know the ignition system on your truck but I would start with that. Unfortunately I can't help more than that.

 

[CraftsmanQuad19]

If there is an ignition module, try that. My impala misfired on every cylinder and had zero power, thing barely ran. New module and it runs like a top. Not EXACTLY sure of the setup on that truck but maybe similar?

 

[Kesh2011]

I did changed the ignition coil pack a year ago with no change in performance.

 

[Uncle Gump]

If you seafoamed the engine... it probably cleaned the plugs a certain amount. That would alter the plug read to an extent.

What kind of plugs are they? Anything other then Motorcraft or Autolite in my experience just don't perform as well.

 

[Kesh2011]

motorcraft platinum agsf32fm

 

[Uncle Gump]

Ok...

I think I would put a vacuum gauge on it and do a little checking to see if there is an exhaust restriction. With the misfire code you're dumping a bunch of unburned fuel into the converter. Google restricted exhaust testing for the how to. It may not be the problem... but you can eliminate that possibility easily.

 

[Kesh2011]

I thought seafoaming the engine would foul the plugs. Truck has 180,000 miles and is almost 20 years old. I may seafoam the engine again since it probably has never been done.

 

[8thTon]

Mechanic in a bottle isn't likely to accomplish anything but pissing off the cats.

 

[gungfudan]

P0300 Random/Multiple Cylinder Misfire Detected

P1684 Metering Oil Pump Position Sensor Circuit

P0300 seems to be the culprit for the rich running. It makes sense for clean plugs because there isn't just one cylinder running rich, so the plugs stay clean. I don't know the ignition system on your truck but I would start with that. Unfortunately I can't help more than that.

Do you think it could be a bad injector or pcm issue telling the injector to stay open longer? I am probably way off the mark just a thought.

 

[Kesh2011]

I don’t know about the injectors. I did put a mechanics stethoscope on them and they all sound the same. After doing the above service that I described I disconnected the battery to reset the computer. I will wait for the check engine light to come on again and check codes again. It does feel like there is more power and it runs a little better but I don’t think it’s 100%.