hey everyone have alittle problem and maybe some of you all can give some good answers.. i have a 1989 F-350, regual cab, 4x4, 351v8 . now i have a chip in the computer and i'm running the Jacobs Electronics box on this also. just started having this problem, when the truck is first started especially it does not want to idle very happy, very rough, it dips down to around 400 r.p.m. and then picks back up to around 800 to 1,000 and back and forth, drop it in gear and it will stall a few times not always.. i had this to the ford dealer and they ran the scanner on it and no codes come up. they put an I.A.C. valve on it thinking that was the problem ( so did i ) and it did alitle better, didn't run to bad on the way home the idle kinda stayed where it was supposed to. and got home parked the truck and about 6 hours later went to put it in the barn and started with the same trouble again.. i wondering if this thing has a vacuum leak somewhere? darn these plastic vacuum lines what ever happen to good old rubber.. maybe some one else has had this problem and can give me a idea before i spend another $200.00 at the ford dealer this weekend. oh just so you know i put a new fuel filter, cap, rotor, wires on it already. thanks. Ray........

 

any thoughts anyone..

 

did it start doing it right after you put the chip in it, and usually (at least with all the chips i've looked at) you have to run 92 octane for it to run nice, or the timing is wrong.

what is the Jacobs electric box?