pgandy

Hi, thanks for looking.

I'm currently swapping a replacement LS1 ('04 C5 automatic) for an identical engine that was hydro locked. the C5 configuration is the same as the donor car...automatic, accessories, 74k miles. The car is an '04 C5 base, automatic.

The replacement engine was a drop out and includes the harness (intact, connected), the ECU, TAC, and throttle pedal/position sensor (in a separate box) and is still fitted with all the accessories. Comparing the engines side by side the locations/connections for the harness and accessories are a spot on match, although the replacement engine's harness is a little cleaner.

I was planning to leave the harness in place and simply plug into the existing ECU/TAC still in the car. The replacement engine includes the throttle body still installed. I have done this on two other smaller engines but this is the first LS1.

Does anyone with experience with this see a problem? I would have left over the ECU, TAC, and pedal/position sensor from the replacement engine.

Thanks again.


Replacement LS1

tblu92

So if I understand correctly you are still going to use your existing ECU and will be replacing the engine----This should not be a problem Especially if you are still using your old ECM
The only time yo may have issues is if you install an engine of a different year model and more importantly an engine with a different "operating system" that is different from your donor car compared to your existing car's OS system----But even then it is doable with a little more effort (example if the donor car was a manual trans but your car is an automatic then the OS numbers may be different)
More info on exactly what you are doing will help

pgandy

Thanks, I may not have used the correct terms.

The old PCM and TAC module are still in the car, along with the APP (accelerator pedal postion) sensor. I left those in but unplugged the harness from the PCM, TAC and fuse block to remove with the damaged engine.

The replacement engine is same year, same model (C5 Base) and same transmission - automatic.

The replacement engine shipped with an identical harness still installed on the engine...with the PCM plug, TAC plug, and fuse block connectors intact. It also shipped with the PCM, TAC module, and APP loose in a separate box. I plan to set those aside and just install the replacement engine with its harness and plug the harness into the existing PCM, TAC module, and fuse block still in the car.

tblu92

Ok You should still be fine as long as you are replacing the new engine with a drive by wire TB into your existing old engine bay with a DBW system ( all corvettes from 97 on are DBW
PS Are you using the the old T-Body ??

pgandy

I was planning to use the throttle body on the replacement engine.

tblu92

Again it should be all OK-----Only way to know for sure is to try it and see

pgandy

Thanks! I'll report back. Should be doing the drop in (or dropping the car on) in about two weeks.

pgandy

Followup question....

Since the previous engine was hydrolocked there was a check engine light on before I removed the engine. Those codes are likely still on the PCM...I'm guessing low vacuum (hole in the block), bad O2 readings, on and on. It ran on 7 cylinders, enough to pull from the street into the garage.

I am reusing the existing PCM with the replacement engine (nearly identical LS1) but, before starting the engine for the first time, I was planning to turn on the key and reset all of those codes with my OBD Scantool program so I'm not starting out with a host of alerts and warnings.

Does anyone see a problem with that method?

Thanks