Folks,
I am new here but sure am having trouble with my truck I love. Has starting misfiring or what sounds like a skip. Here is what I have done so far;
Had the plugs replaced. Mechanic said they were corroded. Ran better for a while but began again.
Changed the plug wires. Still a touch better but began again. Changed the coil packs and fuel filter. Nothing so far. Had my brother in law (a mechanic) took a quick look and he said the #3 wasn't firing. Don't know if he's right but definitely sounds electrical. It's a 98 V8 4.6. Has been a champ so far but this one has me stumped. I appreciate any help you folks could offer.

Thanks,

 

how many miles? would you happen to know what brand any of the parts were? if dielectric grease was used? does it miss sitting there idling? if so pull the cyl 3 wire off the plug and listen for a tick in the plug bore. that'll tell you if the plug is getting spark to it.

#3 cylinder is the 3rd one back on the passenger side.<if you didnt already know

 

Thanks. Sorry I didn't add those to the original question.

Has 218k miles, shop says the plugs were Motorcraft. Plug wires are BWD Select and coil packs are just Orielly brand- Masterpro I think. Die electric grease was used.
It does not skip or sputter when idiling, just when you accelerate. So much for my BIL assesment. What he was talking about was the 3rd one back on the driver side. I am certainly not trying to avoid a trip to the shop, it's just I live in a small town and the shop has already had a shot at it. I checked all of the other connections there, an orange one and they are tight. Maybe an injector connection? Thanks again.

 

Get a compression check done on cylinder #3

 

3rd one back on the drivers side is cylinder #7.