CGrant

Well I got my ltcc in yesterday and got everything put together.
Followed the instructions and fired the car, it seem to run fine for like 15 seconds then backfired threw the intake and died. Nice!
So I checked and re-checked all the connections and they seem to be fine.
I am going to pull the opti back off and make sure that silly needle in a hay stack gm designed is in the slot properly...for those that are not familiar with a vented opti it has a nipple that comes off the cam and slides into the back of the opti.
What's is weird is I don’t have any indicator lights on at all on the ltcc module itself? It has red and green indicator lights on it and nothing is lit-up?
So Sunday I am going to pull the opti back off and make sure it is on correctly but wanted to start a post on this incase others are interested in this and also to see if anyone that has already installed the ltcc has any suggestions?
I e-mailed bob and we will see what he thinks?

CGrant

Bob just got back to me and i am posting some troubleshooting tips for the ltcc cause i couldnt find a useful thread on here.

When everything is wired and ready to go you should see a power-on blink from the led's, at least one of them.

The green led lights up when valid opti pulses are recieved (engine turning)

Afterbeing away for a couple of years I am going to get my car website back online and this will definately be on the mod page with instructions and pics.
I am a computer engineer and if I am having issues with this I think the average joe could benefit from a detailed ltcc mod page.

CGrant

Ok, i suspected maybe i had the opti on wrong and that was the 1st problem.
As most of us with the vented opti know its like threading a needle.
Anyway the car is actually running now but not that great.
I am now getting 3 red blinks on the ltcc red led.
instructions say "wrong # of hi-res pulses counted diring a high low-res pulse or low low-res pulse" ? greek to me and i am greek
I sent bob an e-mail but any help would be appreciated.

CGrant

ok...well just more disappointment...today spent most of the day chasing my tail.
got a new reman opti and that didnt help, so i went back and got another opti and that one didnt work.
I know they are reman's but you would think the opti sensor would be good on atleast one of them?
So I am waiting to hear back from bob and will probably end up ordering a new opti from gm.
This sucks!

CGrant

OK, This is the 3rd opti on the car, reman but i would think at least 1 of the 3would have a good opti sensor.

checked fuses and they are fine, i put in a 25a just for the heck of it

checked fuel pressure and its 41psi, that should be ok

checked for spark and it shocked me...didn't feel good so i would say we have spark

got a solid green on your ltcc when cranking

after ~20 seconds or so get 2 red blinks, repeatedly

opti is on correctly

ltcc seems to not be firing the coils at the correct time, backfiring threw intake. so coil is firing when valve is open.

I seems like the ltcc box is not translating the timing correctly to fire the coils at the correct time.

verified 12v key on for the ltcc 2 pink wires to my pink wire (95 is pink)

verified 1.8v burst from the opti when cranking (white wire) so it seems to be sending the signal.

can anyone think of anything else i can check?
Thanks!

Mojave

iTrader: (4)

I had this exact problem (blinking red light, poor running, tried multiple optis). Turns out my opti-harness was bad and I wasn't getting a good connection. A new opti-harness from ebay fixed it.

CGrant

i just ordered a pig tail from ebay, my car wont start...backfires threw the intake, timing is off. i dont think the ltcc is translating the signal correctly.
if the pigtail dont work i guess im gonna get a gm opti from summit next?

Mojave

iTrader: (4)

Very stupid question, but you do have the coils properly hooked up to the LTCC box in the proper order? That would certainly cause some timing issues.

CGrant

on the new ltcc harness you cant really mess up the order of the coils, the new ltcc uses the stock gm coil harness and the ltcc just plugs into it.
It's not like the older ltcc that had a wire to each coil, it now uses the stock coil harness from an lsx and the ltcc harness just plugs into it.

Leadfart

iTrader: (2)

I'm having similar problems to yours. I recently installed the LTCC on my 409 stroker Impala SS. I was breaking rotors at high rpm, and I'd had enough.

After troubleshooting everything, new plugs, wires, coils, 02 sensors, grounds, I'm still having the same problem.

My car will idle ok, but everynow and then, it will backfire through the intake, like it's firing too early, then it will die. It will drive, just not very well!

I'm getting no CEL's, and the box is working, according to the diagnostics.

My mechanic, who I finally took it to, thinks either all the coils are firing, or some of them are firing randomly, early.

He thinks either the box is bad, or the LTCC won't work with aggressive cams.

I e-mailed Bob yesterday, and am awaiting more discussions with him.

It seems to me, that I'm going to have to swap boxes, anyway you look at it, to rule it out.

The motor runs great, when it runs. It has put my full weight Impala into the elevens.

LMK if you find out anything. I've tried everything but going into the opti again, and I don't really think that's where the problem is.

CGrant

Hi, yah i am growing tired of all the bs that comes with this ltcc install.
my opti harness just came in and that didnt help, my new gm opti should be here monday from sumitt and my attitude will change sharply with bob if that dont work. he hasnt been much help!
I am a computer engineer and have asked for a schematic and values associated and have not recieved anything but basic diagnostics that i did the 1st week i got this thing.

Redbird1993x

I installed mine Nov. 05, Have 6000 miles on it. I had red LED blink, but can't remember how many times. I emailed Bob and he told me to make sure the grounds for the coils were grounded AS CLOSE TO THE COILS AS PRACTICAL ( like it says in the instuctions). I had made it pretty and run the grounds over aways. When I redid them right next to the coils it solved the problem! I have not had any problems with this ignition after that....it has been flawless! I also used brand new LS2 coils.

CGrant

I used his wires for ground, they are grouned using the fuel rail bolts and also tried grounding them to the frame but didnt make a difference

Redbird1993x

Ok...I grounded mine to the mounting bracket I made over the valve cover on drivers side and to the fuel rail on pass. side...and then took a #10 gauge wire back over to the terminal by the battery, from the coil wire cluster.I have an older LTCC so I know nothing about using an LS coil harness....are you sure it is intact?

CGrant

I will also try taking a wire to ground by the battery but so far nothing is working.
My coils are mounted under the cowl, like the kit thunder racing sells for relocating the coils and ran the grounds back to the fuel rail's but i will try running a wire to ground over by the battery.
I have lt4 valve covers so i cant ground them to the cover's, they are like a composite plastic.

Redbird1993x

Also guys ..this may be obvious, but Bob says not to use low resistance spark plug wires...use standard or Magnecors.... I never got the Magnacors and am still using Moroso Blue Maxx wires with no probs...

CGrant

I have the taylor OVC kit, i tried ground to the post over by the battery but no luck. I also checked for fireworks under the hook from the wires but they seem to be fine, no fireworks under the hood

Leadfart

iTrader: (2)

I'm using the wires Bob recommended, the coils Bob recommended, etc., etc. I have the old style one wire per coil setup, the coils are grounded to the block. I've redone them several times. All the coils are firing. I'm just not setting any codes.

I think either the box is bad, or it could be possible that I stuck the opti in the wrong hole, and it's out of time. But, I've done opti installs over a dozen times, at least.

Very frustrating!

CGrant

hopefully my new gm opti will be here on monday from sumitt and it will fix all my issues but if not i think i am going to give him one more week and if i cant get it going i'm sending it back for a refund and use the opti like normal.
I aksed him about big cams, etc and he said he has cars running the ltcc that run 9's in the quarter.

O Holy P

iTrader: (9)

The grounds must be good grounds and a while back when I did research for my install, I found that the best was on the engine somewhere (heads or block). I took the 4 coil grounds and soldered them all together and connected them to a 12 or 10awg wire and ran them both to the grounding stud that is on the drivers side head where the coil and ICM used to mount. At first I was having ground issues as well. Now I have 7k+ miles on it (has mostly garage duty) and haven't had a problem since. Good luck.

P