Black carbon from exhaust, engine almost died....

[Sworn]

I'm posting this question here, as I'm not really sure where it would fit. Anyway, my 1988 ranger 4x4 has 132k and the 2.9 V6. It always seems to run fine while I'm driving.

Sometimes when I let it idle to warm up the engine will die. I just put in a new ignition module today, sort of a preventive maintenance thing. I was letting the truck run, and to make sure the new module was good. The engine then seemed like it wanted to die and then caught. About this time it spit out a bunch of black carbon from the exhaust pipe.

I've never seen anything quite like this...Last night I had it out on the highway....Maybe I just blew out a bunch of old built up carbon? The truck has only been running on a consistent basis for the last month and a half. the previous owner had been letting it sit for about a year.

Just curious to see what you guys thought. Thanks in advance and sorry for the long post.

 

[MAKG]

You broke something. For whatever reason, it's running pig rich. Start with the self tests.

And for future reference, if it ain't broke, don't fix it. Repairs are not maintenance items, and I'll hire anyone who can accurately and verifiably predict a TFI lifetime as a stockbroker.

 

[krugford]

+1 Check for codes. If you have a fuel pressure tester, I would check the fuel pressure next. Same thing happened to my brothers 91 F-250 last weekend. Fuel pressure was around 75 psi (spec is 35-45 psi). Replaced the FP regulator, problem solved. Also, if it's running that rich, you're going to want to replace/clean your spark plugs now.

 

[Sworn]

Thanks for the info. I'll check for codes and fuel pressure.

 

[Sworn]

it's running pig rich.

Actually it wasn't like black smoke. It was more like black carbon that actually left a mark on my driveway......