Im currently running the LTCC. As some of you know the LTCC gets its signals from the opti but that is it. Anyway, if I had a bad optispark, is it possible to have problems with it at higher horsepower levels VS cruising conditions? My LTCC only pulls a code when the motor produces more then 10psi. I would suspect that if the opti was bad I would get a code from the LTCC at all times? Also when it pulls a code its the same code everytime, code 3. In the past when I had "noise" problems coming from the wires I would throw a different code everytime. Im not sure where to start, at first I was just going to do wires, but now im not sure
What are your thoughts on this?

 

If the Opti pulse signals were corrupt, you would get DTC codes in the PCM. Very possible for the Opti optical sensor to go bad, or for a bad bearing in the Opti to allow irregular pulse pattern.

Do you have the vent system for the Opti? If so, how do you handle the "boost"? Is it possible you are overpressuring the Opti case? Sure sounds like a 1:1 relationship.

Just curious... with all the money invested in the engine, why have you not upgraded to an aftermarket ECU?

 

Im running the FAST system on my car. The code that im getting is coming from the LTCC box. Im running the vented opti but have nothing hooked up to it.

So you think that the opti could work fine under 10psi then have signal problems past that?

 

Still confused.... does the Opti feed the high and low res pulses to the FAST, or through the LTCC..... I'm not familiar with the details of the FAST or with the wiring details for the LTCC. What does "code 3" mean for the LTCC? Probably not a lot of help here.... I'm just curious at this point. I feed the Opti signals to a MoTeC, which has its own add-on 8-channel ignition unit the allows the use of the LS1 coils in direct fire.

The Opti case is plastic. I have seen reports of people wrecking the rotor when the cap distorts under high vacuum (vent line problems). 10psi would also distort the cap and blow air through the bearing assembly. But if you have neither the vent line or the air supply line hooked up to the Opti case, that means it can't be the problem.

What kind of underhood temperatures are you seeing? Where is the LTCC mounted? If you have high temps, does Bob Bailey feel the unit is susceptible to high temps?

Again.... just poking around for possible problems.... and I'm sure you have already thought of most of these.

 

What about the lenght of the dowel pin on the cam?
Is it longer than the pocket it engages into on the opti?
The Opti pocket is .320 and the pin on the cam should be around .280ish

 

Let me setup a scenario for ya.... I ran this setup all last year with no problems. (about 5,000 miles)I put the car away for the winter. Took it out in the spring, it was still kind of cool but I ran 18psi will no problems. I took the motor out of the car, replace plugs, rod bolts, and injectors.(this should not matter) Got everything back together and I believe I started getting this miss only when I ran 20psi(at this point the roads were warming up so I could run this boost), 17-18 it was ok. Pulled no codes from the LTCC and I felt no miss from the car at 17-18psi. From here the problem started getting worse. NOw im at the point were I can only run 10psi or else the motor feels like it hits a rev limitor.

The opti is about 2yrs old. anyway I dont know if that story helped anything, but it confuses me. I pulled all my plug wires several times and there is no signs of burnt marks. So I dont see where there might be a supresion problem, unless you just can see these things? But usually when a wire is bad it will show up under a large load, 6th gear stomp at 60mph.

As I said before the opti seems to work fine under normal driving conditions...so I wounder about this. Im sure its got to be one or the other, (dont want to sound like a cheap ***) but I dont want to buy the wrong one first. Tuition killed me last month

Basicaly the way the LTCC works, it splices into the opti harness, so the fast still gets the signal from the opti, but the LTCC also gets these signals(high/low and what ever else)and and converts them to the coil drivers. The fast igntion configuration is still setup as if I were using the opti only.
Hope this helps!

Its a tough call here, is it the opti or plug wires causing the problem My experience with the opti is, it either works or it doesnt. My experience with the plug wires are they either work or they dont.(as discribed when putting the motor under a big load, if they dont miss here they have never missed under power in the past) If its wires then they are not providing a good enought supression causing the signal to the LTCC to be disrupted(under boost conditions only). If its the opti, its only disrupting the signal under gobs of horsepower.

 

Have you checked the condtion of the coils? Seems like something has been deteriorating under the intense heat, possibly. If the coils weakened, it would show up at high boost, where its getting harder to ignite the mixture. Or, as the wires age, the insulation can start to break down and the spark can take the path of least resistance when combustion chamber conditions cause increased voltage requirements. Seems like everything relates to boost, and boost produces huge temperatures. I can only guess how hot things get under the hood in your setup, but its got to be brutal.

 

The air temp under the hood is not as bad as it may seem. The water temp stays between 190-200. I got two vents in the hood that keep air circulating under the hood. The coils still look brand new. So are you pretty much sugguesting that my problem is existing elsewhere from the optispark? Its a tough call. Because in the past when spark has leaked out somewhere the LTCC box will pull a different code everytime. I guess all I can do at this point is flip a coin and do one and hope that works.

 

Since everything seems to be related to a high load(the big miss is not until 3rd gear) It has to be something in the high voltage area im guessing, because the nothing should change in the opti as boost goes up. So what can I check, ill do an ohms check on all the wires, but what about the coils, is there anyway to check these. Any other suggestings. I checked for corroded wires at the opti but nothing was present.

 

What about feul pressure? If you pump was giving up and not keeping up with demands. You would run lean and have a miss fire and the higher the load the larger the miss. Right? But that wouldn't explain the code you are getting...

 

I did an ohm check on all my plug wires and found 2 that were bad. However that didnt solve my problem. Last night I was looking under the hood and I noticed a 1" solid blue spark which looked like it was coming from the harness that runs along the engine compartment closest to the header on the drivers side. I was grounding onto the header. It was hard to tell exactly where it came from, but the only thing that would have high enough voltage to produce a spark that large would be the head lights(I would think) The power wire for the head lights doesnt run near the header does it? I would think its just a small wire for a reley.

I would think that this spark is possibly interfering with the signal going to the LTCC, but im not sure at this point because its distant from the LTCC harness.

 

the only thing in the car that could produce a 1 inch spark would be the ignition system...was it jumping 1 inch form a wire to the header, or was it just a wire close to the header that was making a big spark over a short distance, like 1/16"
keep in mind...i think this number is right but im estimating to the low side to be sure...it takes 8000 volts to jump through 1cm of air...it can vary with humidity and temp, but that means that you have alot more than 8000v running through that wire. headlight circuits carry 12 volts, but quite a few amps like 5 or so. a headlight circuit couldnt make that kind of voltage.

 

I looked at it more closely last night, but it so hard to tell because it doesnt do it all the time and i cant load up the motor. It almost looked like a spark was jumping between 2 primarys.

Eitherway im still stuck on this. My LTCC claims that under high load its not getting the right number of high resolution pulses. I dont think it matters whether or not the motor is under load when the signal is received from the opti? It works or it dont....thoughts?





I have played with all grounds, added some, nothing has changed a bit.

 

You should check the Hi/Lo res signals with a scope. Those signals should be clean and most important, five volts.

Is the 5 volts that supplies the optispark Hi/Lo res, still coming from the ECM? I would guess that the FAST and LTCC each have their own regulated 5 volts for their respective circuits. They can work in harmony or fight each other depending on current draws and signal grounds between them.

Is the FAST hooked to the Hi/Lo res as well as the LTCC?

The other concern would be the 1" spark. That can only be High Voltage, 25,000+. Any chance that a coil or plug wire is in contact with optispark wires?

Check out signal ground wires, (not the same as chassis ground). If there are any shielded wires, they normally have the shield grounded on just one end.

The scope will give a more accurate reading on pulse voltage, plus they often show noise or stray voltages.

Just my .02 worth. Hope you find it soon. Good luck