[font size="1" color="#FF0000"]LAST EDITED ON 20-Oct-01 AT 11:39 PM (EST)[/font][p]i have a1990 4.9 300 6cyl have replaced tps ,map,o2,coolant sensors,pcm,distrbutor with tfi module wrong out the wires to sensors idles good! butt after you rev it a few times it stalls and starts back up but drags like timing is advanced too much it blows black smoke and is rich fuel odor is it possible catalytic converter is clogged any ideas!! the fuel pressure is 45 to 50 lbs and holds at least 5 minute after you turn off motor please i need my truck back to haul my mustangs!!

 

Check for lower intake leaks . Unmetered air enering the engine will cause the O2 Sensors to richen the fuel mixture .

 

i had a similar problem with my truck. ended up being a damaged fuel pressur regulator. the regulator had busted and wasnt regulating pressure, causing the engine to get way too much fuel and run rich. remember, if its been running rich for a while, you might have clogged your cat(s) also, so be sure to check them after you've fixed the problem. good luck!