Bought my 1st Corvette this January, an LT4 car. It needs a tune-up pretty bad. 1st track outing was horrible once temps got over 210. All it wanted to do was cut out.
I was hoping to go with a torqhead setup but they've been on hold forever so here goes...tired of waiting.

Will the below suffice? Is this opti any good?

https://www.summitracing.com/parts/sum-850060
https://www.summitracing.com/parts/msd-8231
https://www.summitracing.com/parts/tay-74225
https://www.summitracing.com/parts/mez-wp118hd

I have an LT4 hot cam. I suppose I should install that while I have everything off. Heck, might as well get headers too. Timing chain? which timing chain should I go with or will the stock be fine?
Seems like a dumb question, also, but which spark plugs?

Am I missing anything? Jet Tuning software and some datalogging.

 

The MSD stuff is mostly chinese garbage these days.

Is your opti malfunctioning? Throwing codes?

The 95-96 opti's are known to be pretty good units, far better than the 92-94 non vented. I believe Opti Doc is not rebuilding opti's anymore. I have heard decent things about Petris.

Electric water pumps in these cars are tough to do from everything I read. Because the water pump is driven from the cam, not belt driven. Also what do you hope to gain from an electric water pump?

Cutting out/breaking up is usually a plug issue. I would change plugs first and then go from there. Firing the parts cannon is NEVER a good idea.

 

Why not make his opti vented?

What kind of longevity are you guys getting from electric water pumps? Seems like it would be a "track use is best" thing

 

Caution changing # 8 sparkplug. (passenger side under firewall). Someone stripped the **** out of my threads and the car hasn't been the same after the (repair). Clean your old Opti and put new cap on it . Only if you need to

 

If you absolutely must replace the Opti (I'm not convinced it's actually an issue on your car; it could be something as simple as a bad ignition module or coil), there's a guy on eBay who rebuilds them properly. So rather than Chinese garbage, you get something that'll actually work: https://www.ebay.com/itm/233695325126

If I were in your shoes, I would try to diagnose the issues rather than just throwing money at it hoping to get lucky. But it's your money, so best of luck.

Spark plugs, use NGK TR55s. Jet DST may be the only solution at the moment for tuning your LT4, but there will be a significantly cheaper option available within the next year or so.

 

I thought this was the OptiDoc.
https://www.ebay.com/itm/233695325126

 

Optidoc rebuit mine earlier this year, so he was still in business then.

 

95-96 opti is already vented... and the OP has a 96... so...

Ah, there was a thread a month or two ago that said his ebay store had been shut down and the email they had for him was bouncing back, so the thought was he shut down.

Good to see he has not.

 

10-4 on the MSD.

There have been some codes, dont recall what they were. Probably due to the cats, O2 sensors, and smoq equipment removal from previous owner. The car does a lot of weird things, needs some TLC..probably because its about 25 years old. Its a South Florida car by the way. Lots of dry rotted vaccuum lines too. Someone has put an exhaust system on it with flowmasters, also.

Temps about 209 and above...off the line under load it loses spark. All of it. Above about 4000 to 4500 rpm it loses spark, all of it. With the temps around 180. Shes like a bat out of hell. No misfires, runs smooth. Interstate dropping to 3rd gear she will throw you back in the seat and shes a little rocket ship.

With the opti off I figured I'd test it at least. The oven trick I've seen. Crank up the temp on it and see if it still works. If the opti doc is still in business I will probably look into that. I was hoping the summit version provided would be a good one. I wouldnt know.

In South FL in stop and go traffic the temps creep up to 240. I dont like that, its not a warm, fuzzy feeling I get. I want the electric water pump for track use, the stop and go traffic, and lower the fan turn on with the tuning equipment. I might as well install a new radiator while things are out.

 

I imagine the injectors could use a rebuild or something too.

 

10-4. thanks.

If the opti is still good I'll consider it a blessing. I assume any new cap/rotor will do, yes?

 

Thanks, I'll look into those plugs. and thanks for the ebay link.

I figured if things were off or out I'd at least check it over and replace as needed. I don't think I want to do trial runs part by part. Or remove and replace over and over.

 

240 is not normal. Something is going on. My 96 LT4 will not run higher than about 230, basically as soon as the second fan comes on, then it cools back down to 210 or so... thats in 100+ degree Texas temps.

I would drain and flush the whole cooling system, pull the block drains(knock sensors), replace the thermostat with a good one(I prefer Stant), put known good coolant back in. I personally run 25/75 dexcool/water with a bottle of Amsoil coolant boost. You could run similar since you arent worried about freezing in South Florida. Also clean out the area between the radiator and condenser, could be nasty. And make sure the lower air dam is in place.

Putting an electric water pump on will not help your temps IMO.

LT1/4 does not use a cap and rotor. The opti IS the "cap and rotor"...

 

96 LT4 with Procharger here... mine responds at the same temps.

Electric water pumps are not my thing for street cars. I understand they reduce drag on the engine, but there is no free lunch, that drag is just moved over as the additional electrical load requires extra power from your alternator. Now, if you are making a 1/4 mile pass with no alternator on battery alone, yes, you will free up some power. They may be more efficient and possibly free up a few hp, but that electric motor is now something else that can go wrong. It may run more fluid at a lower engine speed that may help your cooling issues, but there may be more going on. Are you sure the front of your radiator is clear of debris? Is you cooling system clean?

 

Definitely pull the codes and report them here.
My LT4 came with an electric water pump and I was hesitant at first. Haven't had any issues and it's actually nice to be able to run wp and fans with engine off between runs at the dragstrip.
Your 8mm silicone wires will be fine except coil wire. I bought that set and the coil wire was too thick to fit in stock location.

 

I’d find the issue before firing the parts cannon, chances are you may otherwise end up replacing good parts with inferior new parts.

I have the Mez electric pump and can say - it’s great. Get the HD one. I’ve had mine 10 yrs and never a failure. It allows you to eliminate the water pump drive gear and run a double roller.

 

96 runs both fans on low, then both on high. If your seeing one at a time there is a relay issue or something else.

I run a HD electric pump, Be-cool radiator, 160 stat with lower fan settings and my 397ci motor runs 180-195. My first pump lasted 12 years then started to act up.
TR55 NGK plugs were good in my stock LT4 castings. I ran a early MSD opti, wires, 6AL box for 10years at least with never a opti issue. I swapped to the Torqhead setup only because of tuning.

 

Opti...
I would change the cap and rotor...the opti itself is probably fine. Yes, you can just replace the cap and/or rotor.
You could get something like this: https://www.summitracing.com/oh/sear...rder=Ascending
or get the complete opti, use the cap/rotor, and keep the rest of the opti for later. The fasteners for the cap are external torx #4. I had such a socket, but it was still too wide to get into the recess for the fastener...had to thin the wall down on the grinder...be prepared for that.
Something like this... https://www.summitracing.com/oh/parts/kti-22870 if searching other sites they could be titled as an E4 or an E-4 size.

Of course like others mentioned, do your best to get scanned, get codes, and determine what the actual problem is first. :-) I suggest determining and solving this before camming.

If the ignition is acting up as things get hot, try cleaning the heat sink for the ignition control module (ICM). The module itself is probably fine. After cleaning, use thermal paste/grease between the ICM and the heat sink. This is the same stuff used to help remove heat from computer chips to those heat sinks (not the same as dielectric grease).

My LT1 experience from my ImpalaSS days...a lot of us would throw a couple of washers behind the coil and the ICM heat sink to get it off of the cylinder head a bit.

Coil and plug wires...
just about anything is better than stock...go for it.

Water pump...
I ran the same pump on my ImpalaSS...daily driven over 200K miles. It did great, the only problems were due to my wiring skills. If you look at that link you proposed, that first review from "David in Ohio" is mine. :-) After you remove the water pump drive coupler, keep it in the car somewhere...just in case you are off on a road trip and need to replace the pump with a regular one quickly you will be able to do so. You will also need to plug the drive hole at the back of the WP housing, if the Mez doesn't come with the plug, I think you just use a 1 1/8" freeze plug.

Thermostat...
make the parts dude gives you the correct one. The LT's don't use the old SBC style.
You want this: https://www.summitracing.com/oh/parts/ado-12th10d
Not this: https://www.summitracing.com/oh/parts/nal-10202456

 

Awesome. Thanks.

 

Lots of good info in this thread.

For the record, normally the temps hit 230 to 235 in stopped traffic. But those hot/humid Miami days at 115 heat index and above doesn't compare imho to GA, AL, MS, LA and TX. Just my opinion of course. It's those super hot days in the summer here I see 240. I'd prefer lower temps when racing and at the dragstrip in particular.

Looking at this 1st:
http://westersgarage.eidnet.ca/ECM-Pro.html

If get that above, then I'm committing to the optispark route. Is it worth it with the intentions of open road racing and dragstrip use?