Splain "Tune-up" for a C4 Please.

[Idaho Slim]

After spending an hour using the search function, I am barely "enlightened". My issue is that I am wondering what tuneup items i should be doing to my new 96 LT-1. It has 53,000 miles, runs great, but i notice a slight drop in fuel mileage since I bought it. The acceleration may be down also, but this could be my getting used to the POWER!

This will be my first tune-up on a newer vette, I tune my older outifts, (Except the diesel) and I am wondereing if I should tackle this myslef, or get lubed up and let the Chevrolet dealer doo it ?:eek

My list so far consists of...........
Oil change w/Mobil One synthetic.
AC Delco Plugs gapped @ .47
New Rotor & Cap (This right for this year engine ??)
K&N Air Filter Relacement
EGR valves etc. replaced, All Delco.
Timing should be what ??

I also have read about the "Free Mods" What do they consist of?
TB? and ??
The only future mods I ever plan on my CFV are K&N's, Magnaflows & 160 Thermostat and possibly a chip.

thanks for any help, and for your patience. Slim.

 

[Ken]

Your list appears to be pretty complete. The Vehicle Emissions Control Information label, which should be attached to the radiator shroud, will give you the timing specs.

The K&N, or any free-flowing air filter, is a definite plus. I wouldn't worrry about the EGR valve just yet; 53k miles isn't all that much, and sometimes when the EGR sends a code, it usually is just a temporary carbon blockage or something that will soon clear itself.

"Free" mods typically don't exist, but bypassing the coolant flow away from the throttle body is a cheap way of keeping the air inlet temperature down, and we all know that cold air makes more power. However, if your climate is too chilly it may cause stumbling problems when the engine is cold.

I wouldn't go too cold with the thermostat; the engines are designed to run at a warmer temperature, although some will maintain that it is way too hot. A 180° thermostat will probably suit you better.

You've already covered another base in that you'll be swapping mufflers to a higher-flowing style of muffler. Getting the air out is the other half of the equation in making power. And a chip certainly couldn't hurt; just be sure who it is that you are dealing with before laying out your hard-earned cash.

 

[Idaho Slim]

Thanks Ken, you are always informative with your posts. The "free mods" i was referring to are what several members post in their signatures, and sometimes during tune-up/performance tips. I have no clue to what they are and was just wondering. I'll search for the reference to them that i have seen.

edit .... as in "Mostly stock all free mods K&N open air box, MAF descreened, TB Bypassed" What this mean ?? Thanks again.

 

[rrubel]

Ken, an LT1 doesn't have a distributor, right? He mentions cap and rotor, but AFAIK the Optispark is a sealed unit and nothing is "user serviceable" inside.

Also, I believe you can't adjust the timing without a computer hooked to the ECU. It's all set electronically.

[RICHR]

 

[Ken]

Yeah, he's got an Opti-Spark in the '96, but I think he would have figured that one out when he went to look for a distributor. :L

As for the timing, one can check that the timing is correctly set by disconnecting the ECU I believe, the same as the old-style distributors on the L-98 and others.

_ken

 

[Idaho Slim]

hehehe, thanks rrubel, i had wondered that, but did not rememer looking, and was covering my bases, what a maroon I is :L

Another stooopid question, how & where doo I "disconnect" the ECU?
I just dont want to make a mistake recalling my "old" tuning methods on this fine vehicle. Thats why i was contmeplating just taking it to a Chevrolet dealer which would be a bit expensive. :crazy

 

[warren s]

Check my website for some simple C4 mods!

 

[Edmond]

I would add tranny fluid and fuel filter on that list. They're not expensive nor difficult to do.

 

[Bluesbrother]

Also, when you do the tranny fluid/filter use synthetic fluid and do a full flush. Then drain the rear end fluid and add synthetic and two bottles of GM posi fluid. Don't forget your rubber weatherstripping either. Grease it up with silicone from a pool supply and wipe it off good. That weatherstripping is expensive to replace!ad

 

[Edmond]

And while you're at it, may as well flush the radiator. Try to get the debris out at the bottom of the radiator. Since the warm weather is coming around soon, a bottle of Water Wetter wouldn't do any harm.

 

[GuzTel]

There really is a cap and rotor on an Opti-Spark and it can be changed but usually the unit goes bad before the cap and rotor.