98 4.2L, hesitation and bucking under load.....
#16
Hesitation
Well, I too have had the same exact problem you have had with my F-150. The difference is that my problem never occured while pulling a load. It seemed to occur durin normal driving conditions. At first, I woul remedy this problem by turning the truck off and then starting again. This worked for awhile then it came back with a vengeance. The first time this problem started I changed the plugs, wires, gas filter, air filter, and spark plugs. This seemed to rememdy the problem. Then it came back so I took it in and they replaced the ignition module(more commonly known as the distributer-less coil) This seemed to have fixed the Problem. However recently the problem started again... No frets though, I went and bought new plugs and spark plug wires and installed them and the same problem persisted. So, I decided to be nosey and take of the ignition module and get a new one. When I removed the module I looked on the bootom side of it and found a crack in it. So I am convinced it is the ignition module. The ignition module cost about $80. In my case, $80 seems to be a ok to spend. I am going to go buy it because i saw a visual defect with it. I hope this help you a little more
#17
Mine is still doing this. Although it seems to do it only when I am coasting and then getting back on the gas again, or maintaining my speed, then giving gas to go up a hill. (It does this between 2,300 to 2,800 RPM's) It doesn't do this very often below that or above that RPM. It does not matter if I'm towing or just me and the truck wet or dry, it doesn't matter. I've really played with it, about the only time this does not happen is when I gas it before it needs it. (Little load if any) Although I'll have to say it really does it the worse when I'm towing. 97 V6 3.55 rearend 5speed. Towing around 1,700 to 2,000 lbs. When I'm towing I never get below 2,500 rpm's ever. I have yet do anything about it, not untill someone founds a cure for it, it will stay that way. I've learned to live with it and get around it most of the time. So PLEASE keep looking for the problem and keep us posted.
#18
I am convinced that mine is going to stay fixed. It has about 500 miles on it since I put in the new (tighter fitting in the boots) autolite plugs. I just got done hauling a full load of fire wood (truck loaded down enough to really notice it). It ran just fine, no bucking or hesitation what so ever.
I actually did try to swap out coil packs with another 4.2L that did not have a hesistation problem and my problem still persisted (before I found the plug problem). So I am 99% sure that the coil pack in my truck is just fine.
I actually did try to swap out coil packs with another 4.2L that did not have a hesistation problem and my problem still persisted (before I found the plug problem). So I am 99% sure that the coil pack in my truck is just fine.
#19
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#22
i have sorta the same problem but with an auto truck. if i run it mid throttle and above it runs great. but if i am in town behind slow traffic the trans seems to slip or go into neutral,the motor revs freely, or it starts bucking really bad. i thought the trans was dying but it shifts flawlessly under throttle it only does it when yer just loafing around slowly. any idea's?