I posted on here awhile back about a problem I'm having with me truck. I got some good info, but I still didn't get it fixed.

I have a 91 F-150 with a 300 6cyl. in it. The problem I am having is that is has a miss to it. When I first start it up, when the (im guessing) "electric choke?" is on for a few seconds, it runs perfect. Once the choke runs and it idle's down, it has a miss to it. It will run, but it's rough. I can't hardly drive it. When I am driving it, it's bad when it's under a load. Once you get into 4th and 5th gear it seems to do better but I think it's because it's not under a load as bad as when it's in lower gear. I replaced the fuel filter, and MAP sensor based on what some other people told me to try. I did a tune up on it about 2 years ago, so I haven't changed anything else on it since this happened other then the fuel filter and MAP sensor. I have checked the vacuum lines and haven't really seen anything leaking, but I'm no mechanic. Also the service engine soon light isn't on. The motor is quiet with no knocks or pinging noise.


I was just wondering if anyone has had this same issue or knows what direction I should go next aside from taking it to a garage and paying a fortune to fix it. I'm just a shadetree mechanic so I'm hoping I can get some answers here.

Thanks again!
Josh

 

well maybe it could be fuel injectors cause i had a problem with mine missing and when i replaced with new injectors that were a bigger# it ran fine but when i put the bigger injectors in they were pushing way to much fuel in so i put stock ones back in and it ran like crap again.

 

my 1990 f150 5.8 351 windsor was doing that and i replaced the overdrive transmission fuse and it fixed it.