Ok calling all experts. This vehicle belonged to a Napa Valley vineyard it developed problems that the company mechanics couldn't fix, no repair history given. Vehicle was sold off bought "as is" come tow it away. Well I have several hours in to it and cant seam to get it diagnosed. Here's what i know.

1 Running super rich - black- hot exhaust- pre-cat at 900 deg.
2 no codes unplugged air flow meter no change in running no check engine light
3 Unplugged throttle position sensor - no code set
4 At idle in park odometer is registering miles
5 spark plugs black

I unplugged to fuel pressure regulator - no fuel leak to vacuum line

Any advice other than JUNK IT

Thanks Marc

 

sounds like a bad fuel pressure regulator or some injectors dumping fuel.

 

x2 on the bad pressure reugulator