Bucking at coast, not at high accelleration...

My 97 f150 4.6L bucks if I'm standing still with the shifter lever in Drive, as well as when I'm coasting or accellerating moderately. The only time it doesn't buck is if I step onit and let it down-shift.
I also, have replaced plugs wires fuel filter and dumped injector cleaner in the gas. Those changes haven't helped. I just took it to a parts store that check for trouble codes free. I have a P301 - cylinder 1 misfire. I suspect it's something electrical and want to find out if I can test the coil pack myself.

P.S. There's also a light fuel smell at start and by tail pipe...

Please advise, if you've tested this before.

 

you can generally test a coil by looking at the resistance in the primary and secondary side. I would look for a thread about this and see if you can find the resistance values. You could also take your DVOM and do a comparison between the "good" coil pack and the suspect one. You should have values pretty close to the same if the coil is O.K.

 

Try this site

http://www.cybrrpartspro.com/Manual%...delLookup.html

Type in you year and model, choose the model that applies. Go to engine electrical, distributorless ign system and then ignition coil pack. Find the part for the 4.6l.

I replaced mine at 80k. The secondary winding resistance was out of spec when warm.

Rob

 

i know the haynes manual will tell you step by step and give you the correct readings for the coil packs. it will also tell you the correct banks to test against.

 

I had a similar problem with my '01 4x4 5.4 Screw. Changed the plugs. They looked new. Also I tested the COP's. Got the resisistance spec from a Haynes manual. They all were right on. The "misfire" symptom is gone. Maybe one was just making a good connection.

 

Don't know if you saw my topic about the dealer trying to shaft me. I had the same problem as you have described. Since I have true duals I could listen to the exhaust to see which side had the miss. I then pulled one wire off the plug at a time and set it on the motor then started it up. If it was sparking I know I didn't pull the right one. I did that until I found the one that didn't spark. I then followed that wire to the coil pack. That will be the pack that is bad. On mine it was the #1 which is the front one on the pass. side. The coil pack that wire went to was the pass. side.