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I emailed back and forth with Brad and yes he shuttdown the ebay store in November. The main issue was the "throw parts at a problem", most assume the opti is the problem, so when the install the rebuilt opti and the problem persists they blame him. This is not his main source of income, so I think the ebay aggravation helped make his decision (ebay ALWAYS sides with the buyer). He is taking a break and I asked if I could share his email with members here he said OK, so maybe advice or the occasional rebuild.
I'm glad he rebuilt mine and I found a NOS opti ( i was going to sell, but not now )
I get calls frequently, that start out with the guy on the phone telling me,
some info, like I just replaced parts (X,Y,Z) and it did not solve my issues with
(starting, stalling, rough idle, how it runs, cooling, the brakes, transmission shifting, or the lack of power at (X) rpm etc,
the guys are frustrated as they spent time and cash but the issues is not resolved!
the "PROBLEM" is most people won't take the time or effort to diagnose a problem by logically isolating and testing each component before the parts are replaced,
and yeah its basically a two step problem, that having a SHOP MANUAL, for your particular year corvette ,
and a few basic tools like a FUEL PRESSURE GAUGE,MULTI METER, AND TIMING LIGHT, COMPRESSION TESTER,
and a CODE READER MAKE FAR EASIER, ISOLATE AND TEST ARE THE BASICS OF ANY REPAIR PROCESS>
you first have to understand how each component functions and how to test its functioning correctly.
it helps a great deal if you know the basics and have access to the tools required to test.
it helps a great deal if you understand how the various sub systems like ignition,
timing and terms like AMPS. VOLTS,RESISTANCE, and fuel delivery work, terms LIKE PRESSURE, VOLUME, and the basic 4 cycle engines design parameters.
theres not a single problem on a C4 CORVETTE, that can't be diagnosed with a shop manual, fuel pressure gauge, multi meter, exhaust back pressure gauge/vacuum gauge and an accurate infrared temp gun, timing light, compression/leak down tester, basic mechanics tools, a set of jack stands and a floor jack.
and a logical isolate and test mentality, if you have access to the internet to ask questions about related tests, PROVIDED you ask the correct questions and test to find the related answers,
yeah, having experience helps and tools like code scanners, degree wheels, dial indicators , a dial caliper, feeler gauges certainly help,
but you can solve problems by simply understanding how components are supposed to work, and how they can be tested to verify they are defective or not!
before you start spending cash, verify the problems source and yeah,
it helps if you have a knowledgeable mentor and some decent tools and a place to work.
and yeah, you could easily spend several thousand dollars on unneeded parts, or labor costs,
at the local dealership ignoring this advice! knowing how your car is supposed to work and how to test the individual components may take time and effort but it will save you a great deal of cash and wasted time .
and yeah, I'm all too well aware many guys find it far easier to spend cash rather than read links and think,
but you might be amazed at how much you could learn reading links and sub links
I get calls frequently, that start out with the guy on the phone telling me,
some info, like I just replaced parts (X,Y,Z) and it did not solve my issues with
(starting, stalling, rough idle, how it runs, cooling, the brakes, transmission shifting, or the lack of power at (X) rpm etc,
the guys are frustrated as they spent time and cash but the issues is not resolved!
the "PROBLEM" is most people won't take the time or effort to diagnose a problem by logically isolating and testing each component before the parts are replaced,
and yeah its basically a two step problem, that having a SHOP MANUAL, for your particular year corvette ,
and a few basic tools like a FUEL PRESSURE GAUGE,MULTI METER, AND TIMING LIGHT, COMPRESSION TESTER,
and a CODE READER MAKE FAR EASIER, ISOLATE AND TEST ARE THE BASICS OF ANY REPAIR PROCESS>
you first have to understand how each component functions and how to test its functioning correctly.
it helps a great deal if you know the basics and have access to the tools required to test.
it helps a great deal if you understand how the various sub systems like ignition,
timing and terms like AMPS. VOLTS,RESISTANCE, and fuel delivery work, terms LIKE PRESSURE, VOLUME, and the basic 4 cycle engines design parameters.
theres not a single problem on a C4 CORVETTE, that can't be diagnosed with a shop manual, fuel pressure gauge, multi meter, exhaust back pressure gauge/vacuum gauge and an accurate infrared temp gun, timing light, compression/leak down tester, basic mechanics tools, a set of jack stands and a floor jack.
and a logical isolate and test mentality, if you have access to the internet to ask questions about related tests, PROVIDED you ask the correct questions and test to find the related answers,
yeah, having experience helps and tools like code scanners, degree wheels, dial indicators , a dial caliper, feeler gauges certainly help,
but you can solve problems by simply understanding how components are supposed to work, and how they can be tested to verify they are defective or not!
before you start spending cash, verify the problems source and yeah,
it helps if you have a knowledgeable mentor and some decent tools and a place to work.
and yeah, you could easily spend several thousand dollars on unneeded parts, or labor costs,
at the local dealership ignoring this advice! knowing how your car is supposed to work and how to test the individual components may take time and effort but it will save you a great deal of cash and wasted time .
and yeah, I'm all too well aware many guys find it far easier to spend cash rather than read links and think,
but you might be amazed at how much you could learn reading links and sub links
Sorry to read this, but not surprised. This is why I get so irritated at every question about problems with any LT car being answered as "It's the opti." And now with one less source for good replacements, the problem perpetuates itself.
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16-'17-'18-‘19-'20-'21-'22-'23-'24
I might add another suggestion when diagnosing problems. When you DO replace something, if at all possible do only ONE part at a time. This might not always be possible, if you have done a major tear-down and have multiple parts out anyway. But randomly replacing multiple parts can lead to confusion and incorrect conclusions.
Maybe I missed it in the thread, but anyone know where I can get a new Opti vent? Or, how can I tell if mine is functional?
Pull off the feed line and put a small 1/4" x 1/4" piece of paper over it while the engine is running. If working the paper will stay on the end even if turned upside down. Dan PS: maybe the optidoc still has some he would like to sell.
My water pump went up on my 95. I don't want to put on a cheap one. Any recommendations on which manufacturer ? Anyone familiar with Tuff Stuff performance products ? At one time I believe Bosch was a superior product but can't seem to find anyone who carries them or even if they make them any longer. I'm sure the supply chain breakdown is part of it, but it's kind of ridiculous. The corvette shop I've used before dosent reccomend an electric one, thoughts on that? Which leads me to the opti spark. While I'm there, going to give that a once over, and because of the opportunity want to either replace it ( haven't had a problem with it) or if the "doctor" is back in, have it rebuilt. Ebay store still looks to be closed. The post above with the update on him said he may be still willing to do an occasional rebuild ? Car has 155 k miles on it, was running great until the water pump went up, and taking care of some other issues while its down, like a/c, radiator and some minor stuff. Any advice is greatly appreciated.
My water pump went up on my 95. I don't want to put on a cheap one.
At this point, I think all replacement pumps you can buy are either manufactured or rebuilt in China. It's all a crap shoot, and I'd buy the cheapest one with the best warranty.
Which leads me to the opti spark. While I'm there, going to give that a once over, and because of the opportunity want to either replace it ( haven't had a problem with it) or if the "doctor" is back in, have it rebuilt.
The only things that ever fail on an opti are the sensor and the bearings. If yours is original to the car, it's probably fine and the sensor is no longer available new. I would not replace a good-working opti: there's no reason for that. If you can't help yourself, then take the OE one off and open it up and clean it out of any crud, and then put it back on the car. These things aren't open to the air, and they get wet every time the car is driven in the rain. There are almost no "good" ones left on the market. Leave well enough alone.
People used to switch to electric pumps here often. I may do it if my pump ever goes out again. You have to change some other items, I forget what, and it costs more, but you do also free up some power, I think about 10hp.
AC Delco factory pump. Last one you'll buy if the car has 155k on it. Replaced my. factory one at 30k just because. Looked spotless and no impeller restriction.
AC Delco factory pump. Last one you'll buy if the car has 155k on it. Replaced my. factory one at 30k just because. Looked spotless and no impeller restriction.
I don't think you can buy an OE-spec AC Delco pump anymore. Even those branded as such are now Chinesium junk.
I too am looking for an Opti vent. Mine rubbed on the pulley and wore almost through. Where can I get one - none of the vendors seem to have them.
As far as I know you can't get one individually, they came as part of an entire vacuum/vent harness from GM. These would go for $80-$100 on eBay, but it's been a good 6 months since I've seen one for sale.
Basically your blue piece that's rubbed through is a check valve, only letting suction go through one way (towards vacuum source....engine). You should be able to come up with a work around, something similar for HVAC systems (heater control vacuum like on a C3 Corvette) or cruise control systems that are vacuum operated. I will do some brainstorming, the ones I'm thinking of are black and white, finding a blue one will tough unless you get it from another corvette....but don't forget '95-'96 F-bodies (camaro, firebird/trans am) with an LT1 will have these, as well as any LT1 engine from '95-'96 in Buicks, Cadillacs, Caprices and Impalas. Either start scouring some good wrecking yards or find a good parts counter guy who will actually open up a Standard Ignition Catalog (good place to start, not a computer screen) and start going through the 'emissions controls' section and/or HVAC section and start looking at pics/descriptions until you find a suitable replacement (physical size, nipple size, etc). That's what I got for you, at least it's a starting point and once you have a part# shouldn't cost anymore than $3-$10! Good luck👍
edit: upon further examination of your picture, you could try a dab of 'Right Stuff' gasket maker, or since you can see how thick the blue plastic is, take a soldering iron and melt/work a little bit of the plastic from edge of burn through spot down to your low spot and melt it shut....then test it with a vacuum pump/gauge and see if holds (I bet it would), you could then put your "bad spot towards the engine, so you can't see it! It looks like you barely rubbed through to the internals, this would possibly resolve your issue and in the meantime you could find a replacement....be mindful of the direction of flow when you reinstall it!
Last edited by '78CorvetteS.A.; 12-19-2022 at 07:18 AM.
I have a couple of used blue filters in my junk box. I had no idea they could be worth $100.00. Dan
The $80-$100 is for the entire vacuum harness, which also contains elbows and other fittings and of course vacuum lines....but obviously if a person has all the plastic parts to reuse, you can buy a lot of vacuum hose for a $100! Definitely hang onto to those, they'll be one of those little hard to find parts that sell for stupid money....actually it's already kinda getting that way👍
I emailed back and forth with Brad and yes he shuttdown the ebay store in November. The main issue was the "throw parts at a problem", most assume the opti is the problem, so when the install the rebuilt opti and the problem persists they blame him. This is not his main source of income, so I think the ebay aggravation helped make his decision (ebay ALWAYS sides with the buyer). He is taking a break and I asked if I could share his email with members here he said OK, so maybe advice or the occasional rebuild.
I'm glad he rebuilt mine and I found a NOS opti ( i was going to sell, but not now )
Do you still have his information so I can reach out to him? My original opti is running fine. Luckily I caught my water pump leak immediately and was able to shut the car down before opti issue but I'd like to see if he would rebuild it for me. Thanks!
02-16-2022, 04:19 PM
Opti doctor update
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