|WYG|SS

93 f150 4.9l 5spd.
113- intake air charge temp. sensor above maximum voltage/-40degrees indicated. (took sensor off to clean cause i had carbon build up but then plastic connector part snapped so i got new sensor today) didnt fix problem.
126- MAP or BARO above or below normal. (brand new in sept.)
327- EGR valve positioin circuit below minimum voltage.



here is what is going on. gapped plugs to .55, ran fine the whole day after doing that. then the next day i would step on gas and feel a big jerk and then drove fine. let off gas and fell a little jerk.
starting out in 1st i would let clutch out and would almost die and then big jerk of power and chirp tires going around the corner. and even shifting into 2nd i would let clutch out and chirp tires. truck idles at about 1500rpm. this stumps me. the 113 and 327 are stored codes and 126 is one that is not reading right when i plug code reader in. but how can a MAP sensor go bad in 2 months. and i dont know if it has to do with temp. out side but it is like 20degrees out now and i dont know if that could affect any senor. never had a problem last winter.

ymeski56

Are you Reading these codes as real time errors or continuous memory stored codes? It your Ignition sys. stock or upgraded (if so specify) the 126 could be caused by a miss. It can't identify 7 cylinders. When I started stretching my gap, I went up incrementally, .002 at a time. There can be no weak link in the Ignition sys. when running that gap! I probably wouldn't be comfortable w/ that gap unless I was running a 48K V coil (I'm not sure on this, it may be safely be done w/ less V's). Are they stock or Plat plugs? I'm not ignoring the other codes, I'm just starting w/ the most applicable for your latest mod.

dr_bowtie

the jerking you feel is the MAP sensor glitching...

clean the grounds...this is probably your culprit...all the sensors share a common ground...once it gets dirty the sensors will read out of range...

Battery to fender....fender to engine....engine to frame...frame to body...those are the grounds....add more if you like...I did

|WYG|SS

yep was the map sensor. was looking around at parts i keep just incase new one is bad and found the map and stuck that on and it ran fine. so i am just using old one now. it is plat. plugs i am using. i figured the EGR valve code was probably something to do with vaccum.

ymeski56

That's cool. Was your new MAP you bought a Motorcraft brand?

|WYG|SS

the new one that just quit working was a BWD from advance auto. so i just got my money back and am still using the one i got with the truck cause it still works good i quess.

dr_bowtie

glad you got it sorted out...chasing parts can be a real nightmare....