charlesedberg Posted July 4, 2011 Report Share Posted July 4, 2011 Hello evrybody! I drive a 1978 cadillac coupe deville...and i've run into a little problem... How do I...or what is the best/easiest way to change the spark plugs. specifically the last one on the left side(grill p.o.v.) looks impossible... Link to comment Share on other sites More sharing options...
BodybyFisher Posted July 4, 2011 Report Share Posted July 4, 2011 have you tried from under the car? I have reached many difficult to get at plugs over the years from under the car Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
Texas Jim Posted July 4, 2011 Report Share Posted July 4, 2011 Interest question... I did plugs in my Dads 78 Sedan, and don't remember any unusual issues getting to the plugs... other than my arms looked like you had used a file on them... they were so scratched up from the back plug and all the "STUFF" that you had to work your arm around to get to it. Link to comment Share on other sites More sharing options...
JohnnyG Posted July 5, 2011 Report Share Posted July 5, 2011 I have also heard of removing the tire/wheel and having to cut a hole through the wheelwell to get to certain plugs. Not this particular model, but it's a possibility. Some vehicles actually had a little "cut here" outline stamped in the wheelwell, then a small piece of metal was used to cover the hole. Never underestimate the amount of a persons greed. Link to comment Share on other sites More sharing options...
KHE Posted July 5, 2011 Report Share Posted July 5, 2011 You can access some of the plugs by removing the front tire and lifting the tar paper flap that covers the camber alignment hardware. That may provide additional access to some of the plugs. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
KevinW Posted July 7, 2011 Report Share Posted July 7, 2011 I drive a 1978 cadillac coupe deville...and i've run into a little problem... How do I...or what is the best/easiest way to change the spark plugs. specifically the last one on the left side(grill p.o.v.) looks impossible... All the plugs can be reached from above while leaning over the fenders. Removing wheel assemblies is for Chevrolet V8s, where the plugs sit under the exhaust manifolds. In the case of #7 (passenger side, rear-most), remove all swivels and extensions, place the sparkplug socket over the plug, then attach your standard 3/8" drive ratchet. When this series of Cadillac V8 is mounted in a longitudinal FWD chassis, the plugs can be changed in less than 10 minutes assuming they're gapped ahead of time; add another couple of minutes for #7 in the RWD chassis. ___________________________________________________ Link to comment Share on other sites More sharing options...
Cadillac Jim Posted July 7, 2011 Report Share Posted July 7, 2011 You can access some of the plugs by removing the front tire and lifting the tar paper flap that covers the camber alignment hardware. That may provide additional access to some of the plugs. This was my solution for the front passenger side on my 1996 Corvette with the 427 engine. That plug was under the A/C compressor and was a bear to get to from the top. For the fastest plug change, I turned the steering full left, whipped out the scissor jack and propped up the frame a couple of inches, and used three feet of extensions; I sat on a little shop stool to spin that plug off and the new one on. I could change all eight in about 15 minutes that way, with all due care in just the right torque, etc. But, it looks like KevinW's solution is best for the big-block Cadillacs. -- Click Here for CaddyInfo page on "How To" Read Your OBD Codes-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data -- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC Yes, I was Jims_97_ETC before I changed cars. Link to comment Share on other sites More sharing options...
KHE Posted July 7, 2011 Report Share Posted July 7, 2011 It's been so long since I saw a big block Cadillac engine that I forgot the plug location. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
charlesedberg Posted July 10, 2011 Author Report Share Posted July 10, 2011 thanx for all the replies got a feelin the #7 plug has never been changed...b'cuz of its position did a 0-60 today...n it took forever slower than a 1985 brougham wit a 4.1 Link to comment Share on other sites More sharing options...
Texas Jim Posted July 10, 2011 Report Share Posted July 10, 2011 thanx for all the replies got a feelin the #7 plug has never been changed...b'cuz of its position did a 0-60 today...n it took forever slower than a 1985 brougham wit a 4.1 That ain't right at all... My Dad had a 78 Sedan and it would smoke the back tires... Link to comment Share on other sites More sharing options...
charlesedberg Posted July 11, 2011 Author Report Share Posted July 11, 2011 yeah....that aint right... took 17sec to get from 0 to 60mph i think the # 7 plug is dead... so i'm runnun on 7 cylinders at the moment :S Link to comment Share on other sites More sharing options...
charlesedberg Posted July 21, 2011 Author Report Share Posted July 21, 2011 finally got all the sparkplugs...n all that changed... the 0-60 acc. is now at 14sec...n it feels a lot stronger though....it should b faster right? also....when/at what speed should it shift into second? and third? rpm? Link to comment Share on other sites More sharing options...
Ranger Posted July 22, 2011 Report Share Posted July 22, 2011 Shift speeds will vary depending on the load. At WOT it will sift at a much higher RPM than if you take off like you have an egg under your foot. Link to comment Share on other sites More sharing options...
KevinW Posted July 22, 2011 Report Share Posted July 22, 2011 finally got all the sparkplugs...n all that changed... the 0-60 acc. is now at 14sec...n it feels a lot stronger though....it should b faster right? also....when/at what speed should it shift into second? and third? rpm? The 1977-79 C-Body Cadillacs with the standard 2.28:1 final drive ratio should be able to hit 60 MPH in just over 10 seconds under ideal conditions. The WOT 1-2 shift should occur close to 55 MPH at around 4000 RPM (peak HP). It is possible to do 0-60 MPH in first gear if your valve-springs are in good shape. WOT 2-3 should occur around 80 MPH. Something to keep in mind if everything isn't original is the OEM transmission torque converter has a relatively high stall speed, to complement the tall gearing; most generic replacement converters do not offer the same performance, but this alone wouldn't account for your performance observation. Have you verified the speedometer calibration with a GPS unit? Another issue with transmission swaps is the speedometer drive and driven gears become mismatched because most other THM400 applications have numerically higher drive ratios. Remove the distributor cap and rotor, and ensure that the centrifugal advance mechanism moves freely, and inspect for wear around the weight pivots. Adjust the ignition timing to 18 degrees BTDC at 1400 RPM while the vacuum advance is disconnected. ___________________________________________________ Link to comment Share on other sites More sharing options...
charlesedberg Posted August 11, 2011 Author Report Share Posted August 11, 2011 plugs, wires n distributor are all new now...the timing i think was set to 21...22 or 23... was at 4 or somethin before the swap acc 0-60 in 12sec now...shifted into second at 50-55mph checked the speedometer wit a gps last summer...so thats all good now i think i gotta get a new generator though...cuz the generator light is on all the time now Link to comment Share on other sites More sharing options...
KHE Posted August 11, 2011 Report Share Posted August 11, 2011 i think i gotta get a new generator though...cuz the generator light is on all the time now Take the alternator to a local rebuilder and have it rebuilt vs. putting a chain store POS alternator on it. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
KevinW Posted August 12, 2011 Report Share Posted August 12, 2011 plugs, wires n distributor are all new now...the timing i think was set to 21...22 or 23... was at 4 or somethin before the swap acc 0-60 in 12sec now...shifted into second at 50-55mph checked the speedometer wit a gps last summer...so thats all good now i think i gotta get a new generator though...cuz the generator light is on all the time now Regarding the new distributor, many generic vacuum advance units do not match the characteristics of the original unit, so if you observe some part throttle detonation (pinging), you may need to limit the range of movement. There may still be some room for improvement. How's the fuel economy? It should be relatively easy to achieve the EPA ratings of 14/17 MPG US (city/hwy). BTW, that 63 amp 10SI (or possibly an optional 80 amp unit) is one of the easiest generators to change and rebuild - a great learning experience. Maybe all it needs is new brushes... ___________________________________________________ Link to comment Share on other sites More sharing options...
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