Tune up help.

My '96 SC is in dire need of a tune up. I must confess that I have been very remiss on maintainence, short of oil changes, and Spark plug replacement. The car has never failed me, just finally realizing that I need to pay some attention to her. I've got 176,000 on her now. She idles roughly, I have never seen a CEL, other than that, she still purrs down the road, but where I used to get 26 mpg, she's doing 20-21 now. As I mentioned, the only under hood maint. has been plug replacement w/ NGK's at 138,000. My question is, where should I start, and what all needs attention? I for sure need to replace the SC coupler, and I have a little oil weeping out here and there that I'd like to address. I don't have limitless funds, so I need to take it a few steps at a time. Looking around the forum I was starting to feel overwhelmed at all the issues I found that could possibly need addressed, I thought if someone could break it down for me it would be easier for me to make a plan.
Thanks in advance, Rick

suggestion: get a copy of CarCode (http://www.obd-2.com) (it's free) and a "dongle" to connect to your laptop computer and OBD-2 port (you have a 96, it has OBD-2 right? 95's were OBD 1.5, can't scan with carcode). If you don't have a laptop consider getting a Dell Latitude D410 or other small laptop used off eBay. That model laptop will run you $200 or less. If there is a used computer store in your area what you can do is go there and get an inexpensive laptop, in a big city odds are you can find a used one for $150 or so if you poke around a bit.

What you would be able to do then is to read and plot out the readings from various sensors etc. which will help you figure out the most important maintenance to do first.

Now as to your rough running. Unless those NGKs were iridiums they are probably due for replacement. Also visually inspect the wires and make sure none are loose. Thirdly when was last time you replaced air cleaner? when was last time you pulled and cleaned the throttle body? When was the last time you cleaned the MAF sensor? Please post answers.

Albertj

Good advice above. Another one that often gets overlooked is the fuel filter, a $25 part that takes less than an hour to replace.

Albertj and AA, thanks for the quick replies. NGK's were not iridiums, I check the air filter about once a year and change when dirty, Ive never cleaned the throttle body nor MAF sensor nor changed the fuel filter. I am going to check and likely replace the plugs first. What brand, or brands besides OEM are recommended? Also, sounds like just good form to replace the fuel filter. Where is it located and what special tools are needed to do this job? At this time I will have to pass on the laptop, unless I can talk one of my kids into letting me use theirs.
Rick

Thanks, AA!

MTRiviera wrote:

Albertj and AA, thanks for the quick replies. NGK's were not iridiums, I check the air filter about once a year and change when dirty, Ive never cleaned the throttle body nor MAF sensor nor changed the fuel filter. I am going to check and likely replace the plugs first. What brand, or brands besides OEM are recommended? Also, sounds like just good form to replace the fuel filter. Where is it located and what special tools are needed to do this job? At this time I will have to pass on the laptop, unless I can talk one of my kids into letting me use theirs.
Rick

no kiddig you need a scanner of some description, given the list of problems you posted. You don't necessarily need to talk the kids into it, if you ask around you will probably find one for free or near free. With CarCode, the dirty little secret is it'll run on a '486 or later Windows 95 or later laptop... check out the site to see the current software specs I could be wrong. Point is you *do not* need a new or a particularly fast laptop. Actually if you get a serial cable long enough (I think either 50 ft or 200 ft is the limit) you can just run a wire to a computer in your house and put CarCode there, it'll be enough for reading sensors while in the garage. (won't help you get driving logs though). And you don't need carcode if you can find and buy another scanner (not just code reader) that works with the 96, I use CarCode, I think it's cost effective but am I right? (shrug shoulders).

Albertj

Finally had the chance to work on the Riv. Changed plugs, Autolite AP 605's. Sure took care of the rough idle. After Christmas I hope to have a little free time and mabe address some of these other issue. Merry Christmas to you all!
Regards, Rick

Those are a platinum plug. May not be the best choice in the L67. Merry Christmas and good luck on the other issues.

I think just replacing the plugs period helped a lot in this case. The platinum plugs can work for a lot of drivers, and for everyday driving. If you do a lot of drag racing, or increase the boost, then you might notice a small difference (increased KR) compared to copper plugs. I use the copper plugs personally, but I also change them once or twice per year. Depends on what the driver needs.

As this car is my wife's dd, stock or close to stock plugs will suffice, I do occasionally drive it, but I got my hard driving and hot rodding out of my system a while back. I do, on occasion, appreciate a full throttle pass now and then, but that's as far as it goes. If these plugs are not the best for my application, let me know...it only takes me 1/2 hr. to change them out.
Regards,
Rick

MTRiviera wrote:

As this car is my wife's dd, stock or close to stock plugs will suffice, I do occasionally drive it, but I got my hard driving and hot rodding out of my system a while back. I do, on occasion, appreciate a full throttle pass now and then, but that's as far as it goes. If these plugs are not the best for my application, let me know...it only takes me 1/2 hr. to change them out.
Regards,
Rick

for a DD IMHO the plats are fine -- the 605s are copper plugs with platinum tipped anode. Iridiums are better *if* what you're trying to minimize is plug replacements and IF the engine is otherwise quite sound. Others on this board have made a good point about puling plugs every so many miles to check on condition and plug replacement is one way to do that - and replacing copper plugs is mad cheaper than replacing iridiums, and also frequent enough to catch problems (worn rings) earlier rather than later.

You might be amused to know that some GM dealers will install the plats on cars that are out of warranty and the owner chafes at the price of the iridiums (not that many owners take their cars back to the dealer at 100K miles for the plug replacement). Also, although it will take an iridium plug, the plug change interval on the 3.6L VVT GM engine is 100,000 miles with "double platinum" plugs.

For anyone who wants an Iridium plug. www.rockauto.com lists the AC Delco 41-101 at 5.56 per plug. They also list the NGK Part number ITR4A15 at 7.53 per plug. They are the same exact plug. If you look at the picture below, you will see two AC 41-101 plugs. On one side of the plug is the AC logo, and the GM part number, on the other side, the NGK part number. If you look even closer, you will see NGK stamped into the metal plug shell. Same plug, and the AC's are cheaper. For an un modded car, these are the best plugs IMHO if you don't plan on going full throttle on a regular basis.