Jeff -

Almost... but last Saturday, I drove it on a 25 mile loop and it ran PERFECTLY.

The O2s are new, barely have 200 miles on them.

When the car is stone cold.. connect the datalogger, start datalogging and start it. sit there ans watch it.

Assuming on a stone cold start is idles fine, watch it until it goes to closed loop to see if the car starts acting up.

Did this happen before the O2 swap too? also maybe you have a bad ground on the O2s.. my 90 Z had that issue with a bad O2 ground

Jeff,

This has been happening for weeks... first it was the EGR, then it was this mystery cause.

At this time, there is no starting! The DynaSpark and LTCC brain are both back that their respective sources getting tested.

I suspect the problem is with the DynaSpark. About the time I had my DynaSpark serviced last year, they had changed from the Mitsubishi sensor to another sensor that was supposed to be "just as good." It wasn't. And judging from the things I have read on the web, my problems are much like what others are getting with a bad sensor in a DynaSpark.

They are now using Mitsu sensors again.

AH.. what is eta to get the parts back?

I mailed them out last week - literally, last Monday afternoon.

I know LTCC arrived; don't know about the DynaSpark. I will email him again today.

Neither have given diagnostic feedback.

I should add, this problem would appear at the strangest times; I wish it was as easy as hitting closed loop. When I pulled the plug and shipped off the parts, the problem appeared within 30 seconds of starting the engine! It started, idle picked up to 1500, I waited a moment for oil pressure to stabilize and as the idle dropped to 1000, it fell apart... idle dropped to 500, it stumbled, missed, sputtered, you name it. It sounded like a 4-banger with a dead cylinder. But a V8 can mask a single dead cylinder at idle; hell even under low to moderate loads you may not always notice it! But this? It was like the timing was going 180* out for a moment then coming back and going out and coming back... it was a condition that, to be honest, I didn't think an electronically controlled engine could ever experience.

Last week - as in 10 days ago - I thought the coils were the culprit. I replaced them and the car ran great. I drove it on Saturday and it got me on my morning loop just fine! Not a single failure! It got all warm inside, closed loop, you name it. It was a round trip loop, about 25 miles total. I left my house, drove about 11 on the first half, stopped for an hour for breakfast, then drove back a different way, which took 14 miles. It also included a final steep hill climb to get back up our house. NOTHING! It ran PERFECTLY.

Last Friday, ran a couple of errands, pulled onto my street and approached my house, it sputtered... as I pulled in, it fell apart. Full op temp, closed loop. I was heart broken.

This entire problem has been heart breaking. First it was a bad EGR (which I have retested). I replaced the fuel pump, the plugs, O2 sensors, coils... The wires are new. I do have new MSDs in wait for assembly, but they are my last resort.

So now... I wait...

Quick update...

No word from Dynaspark AT ALL. I assume he has the part, but he hasn't been responding to emails. I sincerely hope he is ok, because in the past, he responds quickly. No kick backs about being out of town or anything.

LTCC is being checked out, should know more tonight/tomorrow.

Andy; What scares me is this could happen to any of us. Those of us without technical skills would be at the mercy of the local shops. I have been following this thread and hope you track down the primary issue(s).

Thanks, Tommy.

I am so glad I am not at the mercy of a local shop... They would have me by the short hairs and I would not be happy.

As it is, I know enough to know what the problems COULD be or SHOULD be. I am at the mercy of vendors, but that's different. I know the guy at LTCC is straight and honest. I also know that DynaSpark, if they want to survive, will have to be nice, too, especially if their part proves to be the cause.

It could be worse... but this is also the price we pay for aftermarket solutions. I will say this: The LTCC has been insanely reliable. I would recommend it to anyone. I still think the DynaSpark is the cause.

All this fun stuff is making me wonder when we build a new engine for my 87. What is going to be reliable and what will cause more problems. Tried and true isn't always the answer. But I like taking chances.
When you figure it out Andy rejoice.
Steve

Well, Steve... how much of a challenge do you want?

www.eficonnection.com sells all the bits needed to add LSx engine controls to a SBC... kinda fascinating if you ask me.

The guy at Dynaspark is working on my opti, I will know more Monday. The LTCC is in testing and seems ok. Haven't heard the final verdict.

Well it looks like I need to get my but in gear and decide what I want to put into the spare blocks in the garage. The blocks are all 4 bolt mains. Is there a year block that works better in this 87? Have a couple stored ay my son's house.
Have another $5000 coming in in the next month from defect in my house that I repaired. Class action law suite. Easy money.
I have seen a lot of new pistons I am not fimular with. I have always like the exotic. looks like this will be another thread in the future. Hope to see some of you at the Famosa March meets Lol

Let us know what the out come on your project and if you get her going.

Steve

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  march meet.jpg (220.87 KB)

March? That's Sebring.

As for your engine, check with engineholic. He is down in my area and sounds like a straight shooter. I am hoping to get out to his shop and meet him some time.

The latest... Dynaspark is working on it... he was trying to imply that oil got in it.

I have issues with that, because the back side of the opti was dry, and the seals look good on the timing cover. He also implied that the seal on the bearing may have failed.

Either way, there is some serious QC issues going on in DynaSpark land.

Well Andy, hope u get that car figured out :/
and when u do we can hook up !
Steve, there are a lot of nice pistons out there,too many to mention, if you need help selecting jus give me a ring

On a diff. note.... I'm beginning to like this site because of the wealth of experienced people & RESPECT for members, gotta say I haven't experienced this before on other sites.... Hope I will fit in

As far of pics, I dont even know how to post a pic of my own Vette, maybe Andy or someone else can do it for me. I'm jus a machinest ya know ;)

Quote:

PM sent,D.

Quote:

I have faith! I should know more tomorrow.

I am glad you like the place. Your comment nailed my goal, so that means we are succeeding.

We treat people like the adults they are. Not little kids. I never could figure out why a car site had to be "family friendly." It just never computed.

[quote]
engineholic wrote:
Steve, there are a lot of nice pistons out there,too many to mention, if you need help selecting jus give me a ring
quote]

I will be getting hold of you on that topic. Been 15 years or more since I built motors and raced. Divorce and rasing kids on my own slowed me down.
I hope to be on a Sea cruse over easter Vacation . Leaving out of Long Beach. If I have time I will stop by and say Hi. Andy isn't very far from the Ship would like to meet him in person also. Still trying to get up to Lone Pine and visite the golf course an stop by and say high up there.

Steve

steve , stop by anytime give me a call before ya come and maybe i can break away and beat a ball around with you . 408 857 2251

Latest update: not much.

They are still focused on the bearing. If the bearing fails, it will cause misreads... but that only if the bearing becomes wobbly.

I would expect a bearing problem to start at high rpms and then go away as the speed slows. Centrifugal forces and all.

That's why I think the bearing is simply a secondary issue that is nothing more than a future problem. The real problem, in my mind, is the sensor.

More of the same... nothing... The LTCC should be back today. It was shipped UPS ground last week, so it should be here by today, I would hope. Monday at the latest.

I asked this question of Dynaspark, and he hasn't answered it, which makes me believe he can't.

The question, posed as a statement: If I read the HFSM correctly, it will throw a code if not enough information comes in. That's when the H16 or H36 codes are set. Under this theory, they are expecting a set number of each in reference to each other. However, if the system sends TOO MUCH data, the system doesn't throw a code and the car runs like crap. Is this interpretation correct?

Thoughts?

Okay I am not versed well in the LT1 world..

the Dynaspark replaces the opti? What is wrong with using the OEM opti since you are only using the low voltage pieces of it?

The oem died... so I upgrade to the dynaspark.

The Dyna also has the option of going cap/rotor less. This means a lower profile and a better seal - aluminum cover vs bakelite cap.

It should be better, but it hasn't proven itself to be.

I got the LTCC brain back today. I am still waiting on some kind of feedback from Dynaspark.

I haven't heard from them since last Wednesday. I sent an email today. I don't like to over pressure, just gentle reminders that I am out there. Daily nags only make you hated. A couple of times a week makes you look proactive and concerned.

The dynaspark has been fixed... a new bearing and sensor. He said nothing was found to be wrong, but just to be safe.

It will be shipped today/tomorrow.

I should have everything ready for a Saturday reassembly.

sure hope this finally fixes your problems . you are a saint for being so patient .i would be going totally nutso by now

I have been going nutso... it's just that I contain it well!

I have also been blessed with something of a loaner car... which I need to put away before too much longer.

I have the LTCC.

The DynaSpark has been shipped, I just don't know how.

The only thing that could be causing this is a bad memcal... God, I hope that isn't the case.

Quote:

Pony Express

;)

I specifically requested USPS Priority Flat Rate Box. It's the best deal in shipping - ~$11 and it arrives in 2-3 days. Beats the living shit out of UPS Blue Label.

I will be curious how he shipped it. If he followed my request, then it's here today or Monday.

Good luck, Andy - hope the refurbed parts do the trick!

So do I, Brad...

I was out today doing some pre-installation work. Cleaning, detailing, things like that. Nothing earth shattering.

Send them a link to this thread

It may "inspire" them

I can't inspire the USPS or UPS at this time. What is done is done.

LTCC rocks - Bob kicked ass. He tested, cleaned it up, put on a new lid with o-ring and new screws with new o-rings. It's tight and ready to go!!!

DynaSpark - we shall see. It is in transit and I don't have a tracking number. Nor do I know the shipment method. He replaced the sensor and the bearing. He indicated that the bearing had a damaged seal. I think he had some serious QC issues with prior staff. Just a feeling.

So what's the fall back plan?

in reference to? These not fixing it?

There are only 3 other possible causes - A really bunged up harness; a bad memcal; major mechanical fault in the engine.

I can get another harness... I can get another memcal... I have another engine.

Quote:

Gentlemen, we can rebuild it. We have the technology. We have the capability to make the world's first bionic corvette. Andy Bogus' corvette will be that machine. Better than it was before. Better...stronger...faster.

send me the six million dollars and we can get busy!

the dynaspark arrived via UPS today.

I will install tomorrow. The weather has been crappy today.

I am on my way to put this bitch back together. Wish me luck...

I will have an update within the hour.

ok... I lied... another hour. I had a couple of calls come in.

Sometimes going bak to basics works...I'm say'in that it very well could be a valve train issue...IMHO

Update: Everything is in... battery is still dead... charging.

I am going to test fire as soon as the battery comes up. Then put waterpump and everything else back together.

And my phone keeps ringing... I think I will leave it inside when I go back out!

Ok... do we have victory? I can't say. I have been in this place before, but, so you know where this place is.

Everything is back together. Before I did the waterpump install, I did a test run. It started (long crank, opti needed to find itself, how Zen) and ran ok. I only ran it for about 30-45 seconds. Codes and crap, half the sensors weren't hook up!

Installed everything... did a more secure job of mounting the LTCC brain. Now it is held with 4 screws, with nyloc bolts and little rubber isolaters.

On went the pump, filled with coolant, belt, sensors, start.

ran for at least 30 minutes and got fully warmed. Didn't drive yet, but that's tomorrows test. Will start at the local Target, if that works, off to Fastenal.

No problems... beyond the normal LT1 poor idle.

Let's hope it stays that way!!!

Sounds like you may have nailed it. Keep us posted.

I can only hope.

Tomorrow is the test drive... wish me luck... mojo... prayers... karma... I don't know... ANYTHING!!!

As I said in the other thread, all seems ok so far!

The car drove great on a 30 mile urban loop in 80F weather! All streets, all congested.

This is my theory:

I got a code 3 LTCC. This is what I think happened... the DynaSpark glitched, sending too much data into the computer(s). LTCC threw the code, but recovered, the ECM looked and said "you want me to do what?" and goes into limp home mode.

I have yet found a definition for "limp home mode" in the FSM. I need to do more research.

I guess this will be the last official update for a while.

It's been over 2 weeks and there hasn't been a single problem. It's running like brand new!