Misfire under load

cncsparky · August 09, 2014, 01:46 PM

Quote from: Rambunctious on August 09, 2014, 02:29 AM

AC 19307138 plugs...

Any reasoning for using this plug? i?? As far as I can find it is a #2 Rapidfire. Can't find any reference that recommends a Rapidfire for our RV's.

Platinum plugs are best in later model EFI vehicles. They will tend to foul faster in carbureted engines, and on top of that yours is a colder than stock plug that can accelerate fouling if not the right heat range.

IMO, get some stock, no gimmicky plugs like a NGK, AC Delco, Denso etc.

M & J · August 09, 2014, 04:26 PM

Plain old AC Delco.

Oz · August 09, 2014, 06:28 PM

Plenty of us have spent money on "better" plugs. A total waste. The OEM AC Delcos, just like OldRock said.

cncsparky · August 09, 2014, 08:07 PM

While researching his part number, I ran across a forum that said when ACD sold to Delphi several years ago that they moved parts production to Mexico. Quality has suffered since.

Oz · August 09, 2014, 08:16 PM

Why does that not surprise me. N:(

GONMAD · August 11, 2014, 05:22 PM

This is true. The racers even switched to a better quality plug as the 'GLUE' used to bond the porcelain to the metal jacket blows out & rattles & misfires. Unfortunate the bottom line is more important than American made quality products. C Ya! GONMAD

Rambunctious · August 11, 2014, 09:08 PM

Quote from: cncsparky on August 09, 2014, 01:46 PM
Any reasoning for using this plug? i?? As far as I can find it is a #2 Rapidfire. Can't find any reference that recommends a Rapidfire for our RV's.

Platinum plugs are best in later model EFI vehicles. They will tend to foul faster in carbureted engines, and on top of that yours is a colder than stock plug that can accelerate fouling if not the right heat range.

IMO, get some stock, no gimmicky plugs like a NGK, AC Delco, Denso etc.

thanks I have some in my garage. I will switch em out and see what happens. I have my radiator out right now. I'm replacing the fan clutch and I may need a new radiator.

I'm just so happy to have the new mufflers that the misfire problem ain't so troubling. I know I will nail it down eventually. Hm?

Rambunctious · October 09, 2014, 07:13 PM

Okay finally my misfire problem has been fixed. I tried everything under the sun. I thought it was heat related...nope. I thought it was the carb so I had it rebuilt...nope replaced fan clutch thankfully radiator was ok and the T stat was stat. Do you want to know what it was? Drum roll please!...My timing was off by 4 degrees. D:oH! It ran fine on level ground but uphill it got very loud and it would misfire when it got under a heavy load. I looked it up and sure enough that is a symptom of bad timing.

legomybago · October 09, 2014, 07:23 PM

I just knew it was a dizzy issue....