I have a 92 six speed coupe and have had nothing but trouble with the opti. Anyone here ever do a 411 swap?

 

I looked into this for my 92 auto. the torque head Efi system uses the 411 pcm but only works from them for 1994 and later. The 92-93 is batch fired fuel injection and the ccm link is different. Unless someone knows away around that...

 

I've long considered a swap to a 411 or later into my C4 Convertible. But Labor - it is an extensive task. But if your an experienced DIY person then it can be more affordable.

I have a LS1 & Tremic T-56 in my '56 Chevy that I installed in 2007, she has a 411 ECM and I modified the GM ECM harness. My '98 C5 Corvette has the earlier ECM., I hate it.... I have a 411 that's power tuned and I hope to start the swap upgrade into my '98 in a week or two. My '56 runs significantly better than the '98. Upgrade ECM's in C5's isn't that difficult. But upgrading to a 411 or later ECM from a Opti is a serious and very laborious project !! My C4 Engine, 8 k miles, is temperamental and I'm Fed Up with the ECM, I'm gathering parts for next winters project...

You can get your early Opti Spark more reliable, but this also is laborious but considerable less than a ECM, wiring harness install and others items to be completed. But schedule a day or two maybe more, esp if you've never changed plugs wires in the LT1 with Opti.

OPTI upgrade,,,
The later (95,, 96 or so) Opti units have a vacuum line routed from the Dizzy to the intake manifold with a check valve and another vacuum line from the fresh air intake at the air filter. Solves most of the Opti issues. Changing the plug wires and a new AC Delco Dizzy Cap & Rotor is a Nightmare and can take all day or longer. Which is why many never change the wires etc., leading to problems. Finding Opti plug wires that are the correct length is difficult and one must purchased the later Dizzy Cap that does not have the bottom vent, note this latter part is manufactured from a different material. A huge PITA too complete, but significantly less $$ ~$150 - $200... and time. There's several post on this subject.

Upgrading the a LSX ECM

-You'll need to remove all the parts from the front of your engine, alternation AC compressor , etc. Prob a good power wash
-Drop the oil pan and install a new timing cover, PITA, install a ECM crank reluctor (there are several variations), crank sensor, and most likely a new timing chain set and harmonic damper.
-Remove the entire ECM Wiring harness, exhaust, exhaust manifolds, battery etc.. Label the powered wires and grounds

With a LSX ECM,,, your changing from a LT1 with a Dizzy (distributor) to an engine with a modified Dizzy and 8 coils.

You'll need to purchase at a minimum

ECM (re-tuned, prob speed density power tune), LS1 ECM wiring harness (passenger car or pickup or new $$), 8 coils and SBC mounting brackets, Timing Cover with the Crank Sensor bung, Crank 28 tooth Reluctor Gear (mounts to the timing cover), Crank Sensor, Modified Dizzy that has the Cam sensor and rotates the oil pump shaft, two each four wire Oxygen Sensors, adjustable fuel pressure regular, two new Oxygen sensors,

If you haven't already you'll need to install a larger Throttle body BBK or, and 8 Fuel Injectors.

If you purchase a GM wiring harness, then there will be some sensor connectors that need a new connector to match the ones on your engine, and a few to be removed.

The Tear Down, cleaning and Timing Cover Swap is the most time consuming. Plus one has to Splice in the Power wires to the newer ECM Wiring harness.

One issue will be how to handle the C4 Throttle Body, but a good tuner can assist you.

you can get the conversion parts at EFI Connection,
https://www.eficonnection.com/
https://www.eficonnection.com/home/c...x-product-line

That's the basics, there more ...

I've done a few LSX transplant including LT1's. It's best to do the research, this will be a several week part time project Minimum. LS1 Tech Forum has plenty of detailed post and many members that could assist...

This project is best to be completed on a Rack, doing this work with a C4 on Jacks will be very difficult, Oil pan and exhaust, you'll need helpers.

For my C4 I'm gathering parts for using a 2008 C6 Corvette ECM and matting GM ECM wiring harness (preferred is a pass car or pickup) , their a better ECM with RTT and finding a used ECM wiring harness in tip top shape is less $$ and more available. Plus I have recent experience with this ECM and it's become my favorite. The engine in my C4 is a Fast Burn ZZ4 so the front accessory mounts are very different from yours. But I still have to complete the Basics listed above, I dread the timing cover swap...

There's a lot of little details that I've left out, you'll need much research and reading prior to such a task.

If your not comfortable with the timing cover and related part swap and electrical wiring, then I'd refer you to upgrade your Opti Spark unit.

Anyways some of my thoughts from experience and learning from others...

Good Luck,

Michael..

 

I was considering this.

Although I would like to eliminate using the opti sensor and just use the high voltage end if possible instead of swapping intakes, distributor etc...

 

There is a very effective and economical option for LT1 F body cars swapping to a 411 PCM - especially simple for the later model OBD2 LT1s. This is as fitted to the 1996 C4. There are also options for the earlier LT1 equipped cars but there is some mechcanical work as well as repinning the PCM connectors. Here is a link that explains it. https://ls1tech.com/forums/lt1-lt4-m...eo-inside.html
My question is are there differences between the LT1 F bodys and the LTI Corvettes that would make this swap impractical?