A high-RPM miss is a signature problem of the opti. Not so much the opti itself, but the cap/rotor.

How is the idle? Is it rock steady?

How many miles? As an aside, what condition is the fuel in?

Was the car driven at all over the winter? I know for a fact that Mid-Atlantic winters are not show stoppers...

I would start with a basic - replace the fuel filter...

Final question - how many miles?

hm... if the filter fails, the only thing that notices is the tach. I don't think it effects the ECM, it get's its info from somewhere else... I would have to check the schematics to be sure.

if you are curious, I don't think it would cause interference or anything,

let's see...

The oil leak... check the following areas:

* Valve Covers
* Intake Manifold gaskets
* Oil Filter Housing
* and depending on mileage, the rear main seal.

There are no chips for the 1996. You need a programmer that will update the internal chip. Different animal.

Hm... with a handle like that, are you sure you can even see the tach?

bada-bing.

Sorry, had to do that.

Now, it's time for some real help! The tach filter has taken a dump. It's a capacitor on the tach lead that filters out the square waves of the HEI so that the tach can read them correctly.

IIRC, Ecklers sells a replacement kit for a reasonable price.

grassroots motorsports built a bad-assed Triumph Spitfire with a seriously custom suspension and a Mazda Rotary engine/tranny and rear end (IRS from a RX-7 Mk2).

They had the suspension arms Jet-Hot coated for the durability and satin finish. Looked GREAT.

http://www.grassrootsmotorsports.com/archives/rospit.html

unfortunetly, there isn't a good pic of the coated suspension arms. They were done, IIRC, during a final sorting of the suspension.

the best heat shield is the one that goes on the header. What I am referring to is a Jet-Hot coating or something of that nature. It leaves the header protected from external damage and potential rusting, plus, it holds the heat inside. Win-win.

for plugs, I would go with NGK Iridium.

Wires, either MSD or Taylor.

The early LT1 can pop... but I would go with a tune-up, simply put, the Bosch plugs SUCK in the LT1. They just don't work...

dude... that sounds icky.

Corvette Electrics are not as simple as, say, a Cavaliers...

I would advise getting the Helm Factory Service manual, www.helminc.com and going to town.

I have a 1984, 1987, 1992 and 1996 manual, but I donno if the lighting is 100% the same...

hm... hard start, good fuel pressure...

Is it running rich? Lean?

Do you have the Helm Factory Service Manual? I know it will have all the trouble shooting needed to get through this...

How old is the last tune up?

Another thought, I am a big fan of both Seafoam and BG Products 44K. Try them. I have also heard that Chevron's Techron is a pretty good additive.

I am not so quick to blame injectors.

There is a trick, tho laborious for your car, is to remove the injector rails, and put little paper cups under them, and test fire them. Just to see how the pattern is.

You may want to have them blueprinted, too. It never hurts.

It could also be a clogged filter, but that usually comes into play when hot for some reason.

the TC is a seriously cool piece.

I don't fully understand them, but have enough understanding to know what they do... just don't know why!!!

I will never pretend to be an AT expert.... no way.

That's why you're here!!!

It sounds like a fuel pressure problem.

a few thoughts... get a gauge on the rail. expect, when cold, to see at least 20psi. anyless, there is a problem.

try this, too. turn on the key, count to 2, then start. if it fires, the check valve in the fuel pump is bad, and it requires a new pump. however, it's not crucial, so a simple count to 2 will get you by until you want to replace the pump.

they charge 400.00 for the Fidenza aluminum flywheel. I don't see the problem.

the TC does a helluva lot more than some overpriced slab of aluminum.

the stock 9.5" wheel (rear on stock 96s) will take a 285/40/17.

I am not sure what the front 8.5" rims will take....

Personally, I would stay with the stock size tires on these rims... the added section width will only increase squirm.

If you really want more tire, get 11" rims... that will allow upto a 335 section width tire. It will plant better. Do 9.5" rims in the front.

this is the GS setup and works pretty well.

sweet!

I love how manual transmission folks complain about the weight of the DM flywheel, and NO ONE ever comments about the weight of the TC... Most facinating.

the JL's are nice.

I would upgrade to the 3-way series... I did this in my 92:



the SQ is seriously insane.

It's the best I have heard in a C4. Period.

Those speakers are Canton RS3s. No longer available in the states, sadly.

oh. the dreaded Tech II. Sorry... I don't have one and would love to get one.

sounds like a good basic setup.

a few thoughts:

1) what 6" components are you looking at? I would suggest mounting the tweeter a bit higher. The sound get burried otherwise.

2) what subs? kickers? I would look for JL Audio 8w3v2 or Boston Acoustic 8". Just preference.

3) amps? Check into ArcAudio. I agree, 2 amps are better than one. the sub amp can mount to the rear bulkhead, the front stage, either under or behind the passengers seat.

you need what I don't have - the Helm Factory Service Manual for your 1993. www.helminc.com. That is the same book the dealer uses, get it. You will need it anyway, and this is as good a time to get one as any.

If I had that manual, I would check it, but my 1992 doesn't have PKE, and the 1996 manual I have may or may not apply.

They are really good tires. You won't go wrong.

This is a job for AUTOZONE!

Seriously, their website will tell you all the xrefs you need. It's not 100% accurate, but for the big stuff, it's more than ok.

As for alternators, the later C4 used a hotter 140 amp unit. So you would want to keep that. My best suggestion is to get your existing alt rebuilt by a local professional.

Sweet!

Welcome aboard!

cool!

If you need us, you know where we are.

the tensioner? it's only one piece... there is a pulley on a bolt... and the tensioner itself just bolts to the accessory bracket.

You need a tool to pull it free to feed the belt around. There is no adjustment.

If your tensioner is in 2 pieces, you are boned, sad to say. But it's available at any number of auto part stores.

Joe's right, but I am not a fan of getting rid of them all.

The precats are more or less a waste of space. They were put there to help cold start emissions... which, technically, are the worse ones out there... but are also the most nebulous, because their effect is done within the first mile of driving, then you are stuck with them for the rest of the trip.

My feelings are like this: We as performance car enthusiasts, are under the gun. The more we mess with the emissions controls, the more we pollute. The more we pollute, the more attention we get - the type we don'e want or need. A little self restraint and responsibility here will go a long way toward keeping the man off our back.

I don't agree with the draconian measures that CARB and other states are doing, but I do know a need exists.

And you folks in FL better keep an eye out - CA, TX and FL are the top CO producers, it won't take long before emissions testing comes back to FL. And at this rate, with the insane number of FL Corvette owners (I am sure that Fbody, Mustang and others are equally guilty) gutting or otherwise removing their cats, it won't take long for that testing to come back... and none want to hear about it. Tough. You have been warned. And as soon as the EPA withholds federal monies, things will change.

However, if the FL folks who have removed the cat start putting high flow cats back on, you could slow that kinda big brother invasion. I am not kidding. Oh, and modern high flow cats are not gonna cost you all that much $$, under $150.00 and if you do a custom setup with two smaller bullet cats (on an L98), the power loss will be under 10hp. It's that minor... add in some torque inprovment, it's worth it.

Just some food for thought.

Sorry to hear about your illness, glad to hear you are back in action!

Even tho it's not a Vette, a few thoughts on your project:

1) The EGR is NOT your enemy. I find that most folks who remove it don't know what it does. It does one thing, and does it well, that effect two results. It feeds a small amount of exhaust gas into the intake. The results are two fold, one, the reduction of NOx emissions and the other, a reduction in combustion temperatures, which results in less chance of detonation. For specifics, you really need to get the Helm Factory Service Manual for the year of your TA. It will have the harness diagrams you need, both wiring and vacuum.

2) As long as you are using EFI, 95% of the sensors will stay. About the only two things that can go are the pre-cats (done, thanks to the headers, thats even if the Fbody had them) and the vapour recovery. EFI sensors have been confused with being an emissions control device, but the reality is that EFI is an EFFICIENCY DEVICE. It needs the O2, knock, MAF (or MAP, or both, depending on vintage) and temp sensors so it can calculate the most efficient charge it can deliver. Otherwise, you have a carburetter.

3) A couple of thoughts regarding the exhaust system. I am a fan of high flow cats. They do a couple of things, one being is apply a touch of back pressure that helps savaging, takes some of the boom off the headers, removes that uncontrolled combustion smell (fine at the track, annoying on the street) and as a result, keeps the air clean. Win-win-win in my book. The rest of the Fbody's exhaust is a mess... the chassis sucks for fitment, check with SLP for some options.

4) The ECU is not going to be easy. You will need a dyno to do it right, but really, I don't think you have done enough to require it. It's not like you raised compression or made a 383 out of it. The changes have been minor. I would recommend an Adjustable Fuel Pressure Regulator, it will help you tune the fuel flow to the injectors better. You may want to investigate some of the laptop based systems that work through the printer port. They are pretty cool, but I can't remember brand names off hand. The mid-80s ECUs are rather crude and are not heavily supported anymore.

A couple of websites for you:

1) www.corvetteplenum.com - he machines the stock TPI plenum to improve breathing.

2) www.thirdgen.org - specializes in your vintage F-bodies.

with 144k and no maintenance history, it's time to do some!

I would be willing to bet you need a complete tune up. I am also willing to bet that, as I said above, that the IAC is bad. The Throttle Position Sensor might need adjustment, too.

If you haven't done so, I would swap all fluids.

hm.

This is an age old question... and I will give the age old answer.

The C4 Bose systems are really restrictive. Replacing everything is really the best bet.

You can use line level converters, but the ones I have heard just don't sound all that good.

It's like this, gut it all, replace with a niceish Alpine/Eclipse/Pioneer, a nice set of speakers and you will be surprised how much better it all sounds.

That's the simple start...

gee... I really need to compose an Audio FAQ...

There are a few more bits of info we need, but I will still take a stab at it.

For future reference, the exact year and engine, mods (if any) mileage and a brief maintenance history. These cars vary so much from year to year, it ain't even funny.

With that said, it sounds like a bad Idle Air Control (IAC). It's not dead yet, but it is failing.

Love them tips!

Welcome!

:thumbleft:

hi, Ron! Great to see you!!!!

you really need to shrink that avatar... great pic, tho!!!!

howdy!

Great to have you aboard!

More "new" folks, that's great!

:thumbright:

them damned things!

they move around, no question about that.

In some years, they are on the inner fender... on others, they are down next to the radiator, to the left of the radiator, near where the support strut is for the hood.

also, chase all the wiring back, and confirm nothing is broken. wiring in pre-1990 Vette's is suspect at best.

thanks!!!

I would feel better with his permission, tho.

Ron, welcome! Great to see you over here!

I don't think we can republish those manuals, they are copywrited, and without his permission, we could get into trouble.

Some of those topics we have already covered in our Tech Library, already. Check it out!

cool! glad to hear all is well.

ujoints can make one think the bearing is failing. It's one of those things where it is perhaps a good idea to replace both the bearings and the ujoints at the same time. it does save on the labour a bit.

huge improvement!!!

yea, bearings are not too bad... just be sure to have a supply of T55 torx sockets... well, depending on vintage, that is.

Quote:

The amount needed is rather nebulous, but on page 4, it states:

"Pump out the old oil, reverse
the hoses on the pump
and fill with the two bottles
of additive, topping off with
gear oil until full. It takes
about two quarts. Reinstall
the plug, lower the car, and
it?s done!"

It finds it's own level.

As for the transmission... According to the 1984 Helm Manual I have, it requires ~1 quart for the 4spd, and the OD unit requires ~2 quarts. Again, I suspect these items will find their own level.

I am pretty sure the 4spd uses a conventional manual transmission fluid, and the OD uses conventional auto transmission fluid, Dextron II or III.

check the Tech Library, there is an article on diff fluid changing.

not sure about the levels in the 4+3. I will check.

I am betting money you have a bad coolant temp sensor.

Next time you start the car, flip the gauges to the coolant temp display and then watch.

If it spazes out, you have your answer. The coolant sensor is on the waterpump and feeds vital temp data back to the PCM.

Otherwise, take the car to Autozone and they will read the codes for free. Don't buy anything until you run it by us.

This is not a coil related problem. If anything, it might be a bad connector on the ignition module, but they redid them for 1996 to make them more reliable.

you need a new EGR valve.

here is the rub... new amps are not Corvette specific, they are generic amps.

if you can fix yours, that would be best.

Bose does offer replacement, but they are not specific amps. This means they are not equalized to the Corvette interior.

Another option is good used parts, and then making sure they are good... and installing new drivers. Bose sells the drivers.

The main failure part on the bose amp is a capacitor. This explodes goo everywhere and causes all sorts of problems.

I am not a fan of repairing the Bose systems.

First off, it ain't all that great.

Secondly, the new amps are not Corvette specific, they are generic amps. This means they just don't sound as good as the OEM... and the OEM didn't sound all that good in the first place.

For the cost of the option ($1,200 or so???) and the repair (upwards of $600), there is better ways to spend money.

That kinda cash will buy a nice head unit (Alpine, Kenwood, Eclipse, Pioneer) and speakers (Polk, Infinity).

And I am sure it will sound better than anything Bose has ever sold.

this is why we need to get tirerack.com as a link again...

I have had great success with Kumho, too.

My current tire is a Toyo, the worlds greatest tire... cause they were FREE! I won them from Speed TV back in 2005.

what kinda issues are you having?

Many issues on a C4 can be handled by a good general technician. In turn, it does not require you to spend huge dollars at a specialty shop.

Not all specialty shops are bad, but they do have a generally poor rep of burning people on the bill.

A woman over at CF got raped by a shop up in Illinois a few weeks back... she overpaid by at least 1000.00, because they double charged on labour.

Just be cautious.

I think this has been answered over at CF.

The thread that links you to the motorcycle guy, that's who I agree with.

Break in is a rather nebulous term. The bearings are hydrostatic - they float on oil... no break in there.

The cam is a little of both, and that's why there might be a break in required, check the cam specs.

The key is setting the rings. Thanks to harder metals, it's much more sensative to break in. Your window of opportunity is limited. From what I remember on that link, the idea is to load the engine, which will increase combustion pressures and force the rings to spread and seat where they belong, not too high on the groove or what not.

static does not imply ignition noise to me... I would expect a whine that varies with the engine speed.

on the C4, by each kick panel, is a main ground point, check that for corrosion. Same with the ground strap by the battery. It more than likely will require removing the battery and cleaning everything. I used a steel brush... on the end of a pneumatic die grinder, to get rid of the corrosion on my 92.

switch keys... that's a great first step.

the resistor puck will wear, and when it does, it won't make good contact inside the ignition.

I will do some checking in my 1996 FSM and give you some pointers on the "resistor" fix.

climate controls... that's the biggie there.