Bucking under acceleration

Agreed on the symptoms...we'll see. Looks like the part won't get here until tomorrow, so I'll go get the truck today.

Thanks on the dealership comments. She interned at a local dealership and it was a miserable experience. She is now at Sewell Cadillac in Dallas. They take very good care of all of their employees.

In a perfect world, she would open a shop specializing in 5th-9th gen (1967-1997) F series pickups. She has a 69 F100. Her daily driver is a 2008 F150. She is not shopping for a 9th gen. I'm jealous, and I'm not a Ford guy.

 

Thanks again to everyone. The new ignition coil did the trick. Replaced it in the dealer lot. Drive around 75 miles since, mix of highway and in town. No issues.

Service guy had no idea why it didn’t throw codes or how the tech identified it.

Hated to pay the diagnostic fee, but I’m still into the fix for under $200. Sure beats a car payment.

 

Bet you're glad it wasn't the fuel pump after all

 

I've run into this problem and thanks to this forum again I have an idea it's the same issue.. second time yesterday it was fully warmed up and when I'd push the throttle too much the rpm spikes beyond the power that I'm receiving. Thank you so much!

 

Whatever you do, only buy Denso coil packs. And never buy them from scAmazon or fleaBay (counterfeits are rampant). Stick to Summit Racing or RockAuto. Look up your part number at www.densoautoparts.com to ensure you're getting the right part for your truck.

Why Denso? Well, for one, that's who made them at the factory, it lasted you this long and their part quality hasn't changed, but more than that, tests have been done which show Denso fires hotter, stronger than store brands. We've also had a myriad of performance complaints from people using store brands, and even popular aftermarket brands like MSD.

 

I had a faulty coil on my 2000 that would intermittently cause the bucking and no codes. Found it by unplugging them one a a time. That one had no decrease in idle speed. All my other bad coils have had a CEL intermittent, steady or flashing and a misfire code. Yup only Denso coils.

now you know what symptoms a bad coil produces. Get a spare because eventually you’ll have another go bad. After four over a five year stretch I just replaced all the original ones.