Frizlefrak

The intake, upper plenum, fuel lines with crossover tube, the TBI's with injectors, and all the sensors. If the throttle cable was modified, you'll need the original. You'll also need an original 84 distributor, as they had to use an earlier HEI with the carb. And, of course, the air cleaner & Thermac assembly.

You'll also need to see what they did regarding dropping fuel pressure....Crossfire needs 9-13 psi, carb about 4-5. They probably used a bypass regulator of some kind. Get rid of that, the rear TBI on the CFI will have a built in regulator.

Gather all the parts, you can have it back to original in a day. Not really a big deal unless they butchered something (which is likely). Then it's a matter of how bad they re-engineered it.

MonteHall

if everything is gone (cabling/ecu) whats my best bet then?

Frizlefrak

Stick with what's in it, or find someone parting out an 84 at the very beginning and grab the ecm, harness, intake setup, and sensors.

There really isn't much to an 84.....no body control module, no VATS, no ABS....a computer, a harness, and the intake and emissions stuff. Quite simple. Are you sure the ECM is gone? I would think they would have just left it in place.

MonteHall

I don't know... the car is in Indiana with my wife, and she'll be returning to Texas at the end of the month.

A friend mentioned I might get decent mileage if I just put an Edelbrok 650 on it.
Can an intake/injection from an 85 go on it, or is that more trouble than it's worth

ps374

No matter what was wrong with the CF it seems to me it would take more skill to replace a CFI system with a carb. Fuel lines would have to be custom made, sensors deleted,computer items changed or some how overcome. Would you have to make a custome harness to fit the existing. Seems much easiers to buy a FSM and just read it to corrcet what was wrong with the CFI system? and wasnt space limited to fit a aircleaner under the 84 hood?

Frizlefrak

TPI can be done. Whether or not it's worth the trouble is up to you. Minimal gains over a stock Crossfire. If you got a TPI for same cost, it would be better. Would be relatively simple if you have the complete TPI (intake, computer, and harness). Keep in mind that an 85 ECM would be the best to use (no VATS). 86 and beyond you'll need a VATS signal generator or the ECM will disable fuel trim.

Wiring a TPI in place of a CFI would be a PITA.....of course, you can always mount the ECM someplace other than the stock location (under the pass side dash pad) where it's easier to wire. Keep it away from moisture and engine heat.

Remember, it depends on your skill level. We've done 6 Fiero V8 or 3800SC swaps now, so swapping engines and mgt systems has gotten routine for us. Converting a CFI Vette to TPI would be a walk in the park.

You can put a smaller carb on, or re-jet what you have. But EFI has a lot of other advantages....driveability, easy starts, runs the same at any elevation, better fuel economy, lower emissions, longer engine life, etc. The last time I rebuilt a carb it was on my Briggs & Stratton lawn mower Serious. I haven't touched one on a car in decades.

There are always stand alone EFI units, but now you're talking $$$. Why re-invent the wheel? CFI and TPI systems are cheap and abundant.

h.d.fire

And when they do, I get to pick up the pieces. In the Fire service we call it "job security".

MonteHall

that's just what the seller told me... who knows the real reason.

Frizlefrak

I do.

The previous owner believed what someone who'd probably never seen no less driven an 84 told him.....he'd get more power with a carb. So, he went to the time, trouble, and expense to convert it to carb only to realize it didn't run any better (if as good) as it did before, and he'd lost all the benefits of EFI. Then he bailed.

MonteHall

I know that it was parked in a barn for 10 years or so... the Carb modifcation was installed in 1999. He's only been driving it for the last 8 months. (that's when it was registered)
He pulled it out of "storage" when his sister died, and he drove it as a tribute to her (hence the "in memory of" stickers on the back window).
He's a mechanic at a mom-and-pop shop, and he was some upset at letting it go for $3500, but once he saw that cash, it was over. His dad, who runs the shop, told him "that'll go a long way to paying back your taxes."

I'm guessing he needed the money.