engine surges then bogs down only between 1000 to 1500 rpm driving and idling. on 1993 Ford F-150

does it only while giving it throttle. smells rich. what could it be? no codes but one time the ck eng light came on and it suddenly cleared up temporarily

by in North, SC on February 11, 2013
3 answers 4 comments
ANSWER by on February 11, 2013
poss plugged exh system.confirm with muffler shop
COMMENT by on February 11, 2013
wth? would do it all the time if that was the case
COMMENT by on February 11, 2013
the more throttle u give the less exh can leave your system and will cause excessive back pressure
COMMENT by on February 12, 2013
thanks but it runs fine above 1500 rpm. does this change anything?
ANSWER by on February 11, 2013
Agree with #1
ANSWER by on February 11, 2013
The symptoms sound like a clogged exhaust,but another possibility that can cause a rich running concern is a faulty air charge sensor that is mounted in the lower intake.Whrn these go out they can make the exhaust glow cherry red due to excess fuel injected into the engine.Just a thought,and easy to check by removing it and looking at it.
COMMENT by on February 12, 2013
Thanks. I think what everyone else missed is that it runs fine above 1500 rpm. the surge and die stuff cycles over and over between 1000 and 1500 rpm. I should have been more clear. it idles fine, just not at low rpm with throttle and honestly my exhaust needs to be replaced. btw it doesnt have a cat just true duals and a small crosspipe where the o2 sensor is.