So I put a 'new' opti in my '97 LT1 this spring. About 4 months ago. Got it from Summit.

Ran fine for 4 months, no problems.

Friday on the interstate it died. Coasted off the road and started again after cranking it a few times. Did this several times and had it towed home finally.

It seems to be completely random. It may start and run fine for 15 minutes, it may start and die within seconds, or it may not start at all. No matter what it does though, it does not hesitate or run badily, it either runs fine or will not run at all.

Sets code 1371.

But also 'U1F' which I cannot find anywhere or figure out. I'm using a cheapo code reader, with kewlio 1964 'alarm clock block' digital readout. The manual that came with the reader says absolutely nothing. Gives a list of OBDII codes. U1F not in the manual anywhere. Here's what it does:

-01- flashes.
-02- flashes.
1371 flashes 3 times.
U1F scrolls across the display once, right to left.

So anyway I haven't disconnected/reconnected/inspected/cleaned the harness connections to the Opti yet, but will do so. They are visibly sound and tight, from visual inspection with a light only. Nothing obviously loose or damaged.

From searching and reading other posts it seems a foregone conclusion that my new Opti crapped already. I'm hoping someone has better news for me.

It's still under warranty but I don't have to tell anyone here how much labor is involved with replacing it. Pisses me off. A lot.

 

I've been scanning these cars and reviewing data logs for more than 10 years and never saw a reference of any kind to a "U1F" code. It is an RPO code for a specific radio, but I doubt your scanner would tell you that....

 

OK so wait, doesn't code 1371 imply a malfunction of the crank sensor?

Meaning that even if I do an LTCC conversion or find a used Delteq, I still have to pull the Opti???

 

P1371 Distributor Ignition (DI) low resolution circuit

...the most ominous code for the opti (or opti harness). Yep, you still need a good signal to use the LTCC. You said you got it from Summit, but what brand opti is it?

 

I'll dig up the invoice. I really don't know. I thought it was a Delco or Delphi or whatever but now that I've read more I wonder if I bought a cheapo.

I do still have the original (presumed original w/100k on it) opti I took off too. It was setting a misfire code, running rough like a bad cap does on an old HEI... I wonder if I'll have to put that back on and do an LTCC.

Either way the one on it is under warranty but I don't want to do this every 4 months.

But no matter what I'm pulling the opti right? I do an all-nighter to get it out of there. Only a week of driving the van and I want my Camaro back!!!

 

As Rob already noted, check the harness connectors (both ends) before you jump to the conclusion that its the Opti.

 

What do you mean 'both ends'? The end that goes into the opti of course, but then where else 'back'? At the PCM? Or another junction? Or all of the above?

 

The short Opti harness has 2 ends. It starts at the gray connector on the bracket on the passenger side of the intake manifold, and runs to the Opti. Check both ends.

 

You can use the old distributor and put the newer cap/rotor on for a quick/cheap fix

 

OK so I checked the harness as outlined above. The opti connector appears snug and fine, and when I put the opti in 4 months ago I put a dab of electric grease on it so I can't imagine it's corroded or otherwise not making good contact.

The gray connector was different though. It was not 'loose', but also not fully seated. It was connected far enough that the connector's locking mechanism was engaged, but not fully seated if that makes any sense.

So I unplugged it and also put a touch of grease on it, and snapped it back in fully and tightly.

Drove the car around about an hour and it didn't die once. I however still have no confidence that it's 'fixed'. The connection wasn't damaged or corroded or anything.

I guess all I can do is drive it a while and see what happens?

 

Alrighty, update...

Car ran fine for nearly a week. Died last night just like before.

So I got out and unplugged the gray connector, and reconnected it. It did not seem loose or improperly seated.

Car ran fine the rest of the night.

But also when I unplugged the gray connector, I had left the ignition on, and something under the hood came on when I unplugged it. I want to say it was the cooling fans, but maybe just relays I don't know, was in a bit of a rush to get the f'ing thing started and out of traffic. Plugged it back in and said thing went back off.

It's pissing me off. So today I'll take that connector apart but just a quick visual indicates nothing wrong with it. Not damage or corrosion anyway.

 

So the harness seems fine...

I've been driving it because I love driving it even knowing it may leave me stranded, while driving the van is safe yet may leave me lifeless...

So it only dies after it's what I'll call 'heat-soaked'... so driving around in stop-and-go traffic, then leave it sitting in a parking lot and it'll act up shortly after I start it again.

Then will be ok after it cools off a bit, on the road moving.

Also short-trips it's fine. Roundtrip morning taking the kids to school and picking them back up it barely gets up to operating temp (~3 miles) and no problems on these short trips. Only after I've driven it a while...

 

Have you considered the possibility of the heat soak causing problems with the Opti optical module, or the IC Module?

 

Yeah, but help me out with the details...

Will heat affect the optical module? I mean it senses the divisions on the back side of the lower crank cam sprocket right? Meaning, at some point optical pulses are translated to electrical pulses, and/or does this happen *inside* the optispark or elsewhere? So does the heat of the optispark affect this input?

And then the optispark has an internal IC module I know, which could/would be affected by heat, but isn't there another module mounted next to the external coil on the driver's side head? Could that module be flaking? And why are there 2?

 

There is no IC Module internal to the Opti that I am aware of. The IC Module is on the bracket on the front of the driver's side head. That can heat soak. Shoebox has a "fix" on his site.

Both the IC Module and the Opti optical module are solid state devices. When they overheat, various components can have their operating characteristics altered by the temperature. The module shines tiny LED's through the slots in the wheel. The receptors on the opposite side of the slot produce a voltage when light is detected, and no voltage when no light is detected. The module will have to amplify this signal to produce the two square wave pulse output signals.