I own a 1983 Imperial, along with a copy of the 1983 service manual. The 1983 manual lists the following information on plugs for the 1983 Imperial with EFI : Production Only Plug : RN12YC Service Plug : RN12Y Chrysler Service Plug : 65PR Gap : .035 I have RN13LYC plugs in my car and got them last year from Canadian Tire. I have since driven the car from Vancouver to Calgary, up to Edmonton and return. Plus I have driven it on trips up to Whistler and into the Okanogan valley here in B.C. with no troubles at all. As Dick Benjamin says, these cars will improve the more you drive them. I have found that to be the case with mine. I do not drive it on my work days, only on my days off. Even then the car runs better on the second and third days than it does on the first. And you will find the Imperial to be a fabulous highway cruiser. Smooth, quiet and with decent gas mileage (for a car and engine that size). And you will find the idle to be smoother the more it is driven, as well. Took my Imperial for its first Aircare this week (I bought it in Alberta last year so it did not need to be tested until this year). It failed. Hydrocarbons for this year and moke of car average 50.00 ppm at driving speed and 60 at idle with maximum allowable limits of 182.00 ppm / 344 ppm. My Imperial got 25.00 ppm with 15 ppm at idle. For Carbon Monoxide the average is 0.07% with a maximum of 1.15% at driving speed and 0.02% / 3.96% for idle. The Imperial got 0.00% on both driving and idle. Oxides of Nitrogen have an average reading of 562.50 ppm with a maximum of 1716 ppm. The Imperial failed with 2982.0 ppm. I suspect the problem is with the EGR. Any thoughts? BC AirCare stats show the Imperial averages to be way below the maximum allowable limits. 1983 Imperials appear to be very clean running cars. Bill Vancouver, BC ----- Original Message ----- From: "William" <mopar@xxxxxxxxxxxxxxxxxx> To: <mailing-list@xxxxxxxxxxxxxxxx> Cc: <dickb@xxxxxxxxx> Sent: Friday, April 26, 2002 8:37 PM Subject: Re: IML: 81-83 EFi Spark plugs > Thanks for the tip, Dick. The bad news is that I can't get the RN13LYC's > here, at least not through my regular venues. Any hints on where to get > them? > William > Edmonton, Canada > > ----- Original Message ----- > From: "Dick Benjamin" <> > To: <mailing-list@xxxxxxxxxxxxxxxx> > Sent: Friday, April 25, 2003 9:51 PM > Subject: Re: IML: 81-83 EFi Spark plugs > > > > I have always used RN13LYC (don't forget the L!), or Autolite 945s. These > > are the closest to the original 68ER plugs, which are no longer available. > > The Autolites are getting very scarce also. > > > > The correct gap is 0.035", not the 0.048" given in the manual. I don't > > understand how the core support label could recommend RN12YC - I don't > think > > that would be correct for any of these cars, except possibly the > carburetor > > converted ones. The core support label on all the EFI cars I have seen > > recommend the 68ER. > > > > These cars like to be driven. As you know from reading your engine > > performance manual, the computer "learns" your driving and engine > conditions > > with use, and keeps the car close to optimum more of the time, the more > you > > drive it. > > > > Dick Benjamin > > ----- Original Message ----- > > From: "William" <mopar@xxxxxxxxxxxxxxxxxx> > > To: <mailing-list@xxxxxxxxxxxxxxxx> > > Sent: Thursday, April 25, 2002 7:54 PM > > Subject: IML: 81-83 EFi Spark plugs > > > > > > > Hello all, > > > I am ready to change out the plugs on my 83 EFI. I bought RN12YC > Champions > > > to put in it (that is what it says in my FSM and on the rad support), > but > > I > > > found on imperialclub.com that someone recommended RN14LY plugs. I tried > > to > > > search the archives, as I am sure this has been covered hundreds of > times > > > before, but it keeps crashing my browser. Should I ditch the RN12YC's > and > > go > > > with the 14YL? What is the difference? I am not looking to open up a > > debate > > > of which brand is better, I have my reasons for using Champs, I just > want > > to > > > get the best one. Any suggestions on gapping? 0.048? The car is running > > > better with every mile I put on it for some reason, and I am enjoying > the > > > car more than I thought I would. Thanks for the input. > > > William > > > 83 EFI > > > Edmonton, Canada > > > > > > > > > > > > > > > ----------------- http://www.imperialclub.com ----------------- > > > This message was sent to you by the Imperial Mailing List. Please > > > reply to mailing-list@xxxxxxxxxxxxxxxx and your response will be > > > shared with everyone. Private messages (and attachments) for the > > > Administrators should be sent to webmaster@xxxxxxxxxxxxxxxx > > > To UN-SUBSCRIBE, go to http://imperialclub.com/unsubscribe.htm > > > > > > > > > > > >