84Whitebird

Been thinking about this. Yeah I know the benefits of F I. I have access to a decent aluminum 4bbl intake and carb. I know that a TV cable bracket is made for this switch. Just curious if there is a sticky thread for this here? Has anyone here done this? I believe the only thing the ecm controls is spark and fuel mix for the F I. I am old school enoough that I am far more comfortable with a 4bbl than F I. Any help is welcome.

billschroeder5842

Yes, there a plenty of people who have made the swap , but it is not easy or for the faint of heart.

Your ECM is the heart of the 84. It controls LOTS. You carb is set up to essentially be a mechanical device but your FI is all about sensors and command guidance, Throttle positions sensors, Idle control, MAP and not to forget the O2 sensors.

As you stated that any opinions are welcomed.... unless you are looking for a very involved project, you can dial in the XFire to be a very squared away engine. I was intimidated when I first had mine but grew to love it---fast.

fparkin

my 84 stumble when warm I change the 1 map sensor so far it doesn't try stall after shutting it off at a store and restarting it and taking off and stopping, most time the 2 coolant sensor is the problem so I changed all three of them even 3 O2 sensor

84Whitebird

Not intimidated by it. Put my first engine together in 1971. A 454. did everything. but the shortblock. Cam, heads, intake, carb, headers. all of it. If there is a carb the ECM has nothing to control but spark. All of the other sensors would be gone. Thinking a by pass for the spark control and just unplug the ECM. The reason for gettinbg rid of the A.I.R crap is just to make room and clean up the under hood area. Would love to see a step by step of this change over

84 4+3

You also need to wire the fuel pump, figure out the interior lights, instrument cluster etc...

383vett

I did that to my 84 years ago. Having a factory service manual was invaluable. You need a vacuum HEI distributor, a low profile intake, carb and a lot of time. I didn't hack anything when I did the conversion and later moved on to a Superram and now a miniram.

rklessdriver

It's actually a very easy swap.

Edelbrock Performer 2101 intake manifold fits under the hood with a drop base air cleaner assembly.

As stated you will need a pre-computer controlled HEI or a MSD distributor/ignition box. You will need to rewire the fuel pump relay to be hot when the key is on... Pretty simple to take a 12v switched wire out of the fuse box and replace the ECM hot wire to the pump relay. You will need a return style fuel pressure regulator spliced into the factory fuel lines..... The Mallory PN-29387 regulator works well. The factory fuel pump works fine as it only uses 13psi on the CFI and it's easily regulated down to 6.5psi for the carb. You will need a way to turn the cooling fan on, most people use a 12v switch wired in to the factory cooling fan relay.... Its been done many ways. Aftermarket temperature switch controllers, manual switches to activate the fan and fan hot whenever the key is on.
Will

Tom400CFI

If all the other sensors are gone....how is the ECM going to "know" how to control the spark? It can't. For spark control, you'd need to maintain the standard distributor parts (p/u coil and module) CTS, MAP, TPS (not sure how you'd rig that up), VSS, and possibly EGR function. You'd want the 02 sensors to avoid a CEL, (if you cared about that) but you'd probably get one for rich or lean anyway.

383vette is right; get a mechanical HEI distributor, stick a carb on, figure out how to hook up the TV cable, then re-use all the gauge sensors to feed info your your gauge cluster.

Power the fuel pump like rklessdriver said, or through the oil pressure switch (or both).

You can make an FPR out of the original CFI FPR if you want to. I've done it on a carb'ed SBC into a square headlight, Wrangler. Or you could buy one from Summit/Jegs etc. Either way, return it to the car's stock return line.

bosco022

Google: Corvette C4 Conversions - intake to carb 1984-1991.

A pretty good guide