Powerstroked89

I purchased a pullout LT1 from a 95 with manual, for my 94 auto. I am doing a stroker build on my old motor so I bought a motor so I can drive my car while I do the build right.

I have a few questions.

I know the PCM that came with the new to me motor is tuned, I planned on using it because I believe the motor has some internal goodies the Corvette parts shop didn't know about it. I figured keep the pcm with the motor.

1. Will a tuned pcm from a manual car even work with an auto?

Also, unbeknownst to me, the car has what appears to be an adapter/lines for an oil cooler. This leads me to believe there might be some beefier mods inside possibly?

2. Can I remove this adapter safely since I don't have an oil cooler currently? It looks like it just unbolts and I can use an OEM filter. I wanted to ask before I remove it.

This motor is ready to drop and go once I figure these two questions out.

Thanks for your time,

MatthewMiller

One correction is that if the new engine really came from 96 manual, then it is an LT4 and not an LT1. So it will make a bit more power and rev a bit higher. But there may be some differences not accounted for, like the fact that an LT4 doesn't have an EGR system because the cam has enough overlap to obviate the need for it.

As for the PCM, I would think there are differences between auto and manual PCMs. And since that engine (LT4) only came with manuals, you won't find one that is calibrated for your LT4 and an auto trans. Your original PCM could be calibrated to work with the new engine, though. You could use Tunercat to do that, including shutting off and not reporting the EGR fucntion. But you won't be able to pull the calibration file from the LT4 PCM with Tunercat because it's an OBD2 computer. You need Jet DST for that, which is an adaptation of Tunercat, and pricey. And it won't work on your 94 PCM! So you'll need to buy both programming applications to copy the settings from the 96 PCM to the 94.

As for that filter adapter, I believe that is stock. Leave that on and use the filter for the stock 96 LT4 application.

Benny42

1- no, the '96 LT4 pcm won't work in your '94 as Matt said.
2- That oil cooler sandwich adapter is removable if you don't have the heat exchanger that goes with it.
An oil cooler isn't "required" on an LT1 but it sure wouldn't hurt to add one if you're so inclined. During an engine swap is a great time to do that.

WVZR-1

OP - you've much more research I'd think to do. Everyone has assumed that you've an M6 "pull out" from a '96 Corvette which would of course would be an LT4 BUT maybe this is actually an LT1 from maybe an F-body car. You need to actually ID what you've actually got. It seems you really have "no idea"!!

Regarding the oil filter adapter I believe you do some research and see what it actually is. I'd think that you would likely want to use the oil filter adapter from your '94 Corvette.

Regarding the PCM - is there a part# label on the PCM?

You believe you've "FOOLED THE CORVETTE SHOP" - I doubt it.

Did they FOOL YOU? Maybe!

Powerstroked89

Sorry it's a 95 lt1 not a 96...i didnt say I fooled a corvette shop. I have an lt1 with a bigger throttle body and an oil cooler lines. They didn't know much about it, why tune a stock lt1 with just a throttle body upgrade? How would they fool me by selling me an lt4 and lt1 prices? Lol

It's an lt1, it has an egr valve

I wanted to make sure a tuned pcm to a 95 lt1 that was mated to a manual, would still run properly when the same engine and pcm is mated to my 4l60e. The engine is clearly tuned for a reason, and I doubt it's because the throttle body

Not trying to come off rude, on my phone

MatthewMiller

A 95 PCM should be physically the same as a 94. What I'm not sure about whether or not the same set of calibrations will work from a manual to an auto. I've only seen the bin files from my manual car. Looking at my 96 LT4 (manual) stock calibrations, I see that there are a lot of switches, constants, tables, and diagnostics for an auto transmission that are turned off or zeroed out. I would assume that a lot of those will be turned on for a car with an auto trans.

So the upshot here is that you will probably need to reprogram the new PCM to work with your auto trans. The good news on that is that you can do that pretty cheaply with Tunercat. It costs something like $70, plus you'll need a serial-to-usb adapter (~$15). That program has a function that allows you to compare two bin files, so you can easily what is different in the new PCM in all the transmission settings and change it to match your old PCM. As a bonus, that comparison function will let you see what is different in the fuel and spark tables, too. So you'll be able to see exactly what's been changed in the tune from stock for any performance parts.

Powerstroked89

Ok cool, so just to reiterate so I understand. Tunercat will hook up to the car while running and let me copy the bin file for that pcm. I do that with each pcm and find out what was changed performance wise and enable that on my old pcm as my old pcm is set for the 4l60e. Keep the new pcm as a spare, or set the #'s to enable the ability to run the car with auto.

Doesn't sound too bad.

Maybe there isn't any performance parts in it and my 94 pcm will work just fine. I Just have a hard time seeing why you tune a throttle body only engine and use oil cooler lines on a stock engine.

rocco16

Because most owners really, really, really want to believe the people selling the tuners when they say they can add up to 50 horsepower to a stock engine.

Powerstroked89

Gotcha. Yeah the throttle body looks ported and the cooler lines at the filter are interesting. If it has a decent cam in it, that's great but not gonna be upset if like you said it was just tuned to squeak out some magical hidden hp from the factory.


Here is a picture of the new pcm, I know someone in the thread mentioned wanting to see it.



Also, I got a complete engine wiring harness all hooked up still. Everything looks plug and play. Am I overlooking some indepth work by switching this around? With the old one?

C409

..... If that PCM is a match for the engine it came with you might have a 383 with a mild cam ... read the silver sticker details on the right side of the unit ... Walt W.Bin .....

Powerstroked89

yeah I saw that. If it's a 383, then I got a steal of a price if so. It's the pcm that came with the engine when the corvette yard pulled the engine

C409

..... Compare the VIN# on the engine to the one on the PCM ... if they match , Hooray for you ! .....

Powerstroked89

Yeah, not making much headway on that. Hard to see from the locations I was told to look.

May have to contact the place and see if they can tell me if engine matched the car before it was parted.

MatthewMiller

Sorry, long day yesterday! Yes, this is correct. Except you use Tunercat with the key on but engine off. It has a comparator function that will allow you to compare the two bin files and see what is different. That will make it much easier to just click the settings that are different and change them. On your old PCM you'd want to leave the transmission settings but change any air/fuel and spark values. Or on the new PCM, you can leave the air and spark settings and change the transmission settings. Once you get one bin that has the correct transmission, air/fuel, and spark settings, you can upload it to either PCM any time you want. Save the old bin files for future reference.

EDIT: I was wrong: apparently there is a VIN on the LT engine blocks! Sorry about the misinformation. There is another current thread that tells you where to look:

I would still try to verify the stroke, just to know for sure. So the following still holds. An easy way to tell if it's a 383 is to pull one plug and measure the piston travel with a small dowel or something (make sure it's long enough to not fall in!). 3.48" stroke is a 350, 3.75" is a 383. You don't have to be super-precise, so this should be close enough to tell.

Powerstroked89

[QUOTE=MatthewMiller;1594925983]/QUOTE]

Thanks Matthew.

I contacted the corvette place, the vin on pcm matches the car. I will try the dowel trick and see if I can get a definitive.

I was going to change the plugs anyhow... it has msd wires, kinda curious to see how they run before I put the new Delco ones I have

Msd wires don't fit the stock wire organizers, and with long tubes I bought kinda leary so I don't burn up wires. I do have header heat wrap

JrRifleCoach

You mean that just not true?!

I did tune my very stock 86 and the results bested the Car & Driver tests by two tenths.
Not much to brag about since C&D tested on new cars and my results were on a 120K old car 27 years later.

Powerstroked89

Pull #1 spark plug and can you guess what came out when I could barely turn the crank?

i'll give you a hint, its green, animals cant drink it and poured out like a waterfall.

I used a credit card and purchased with ebay, had all positive ratings too, not one negative. I am not happy.

383vett

It sounds like you bought the motor from a wrecking yard. Odds they didn't know the motor was no good. Give them a chance. Most yards stand behind their motor sales.

Powerstroked89

Corvette dealer who parts out vehicles with all positive on ebay, the ad said they ran it prior. I can't physically turn the crank and I am a big dude. Even put used a break bar with light pressure just in case. I am not sure how you run a car and miss it but i'll give them the chance to answer me back. I have seen head gasket leaks before, this was deluge of coolant. I haven't pulled the rest of the plugs but if the engine is still hard to turn with all the coolant out of cylinder 1, I bet cylinder 2 or one of the others also has water it's trying to compress and can't