After doing tremendous research I think the conversion is not very difficult as long as certain things are compromised. Please allow me to run these things by everyone for comment.
Emissions - 1984 was a very early stage of emission control and the components can be easily bypassed or disconnected completely and be similiar to the '79 'vette, as strictly a toy car for me I feel the emmissions issue is non existant as I dirve the car less than 5000/yrs tops and there are no emision controls where I live and if I must bypass those laws it can be done by either reregistering th ecar as a street rod or an antique.
Intake and Carb - Edelbrock has a combination that will fit under the hood and not force outside body alterations,so on the street it is invisible.
3.Valuation - the value of an '84 C4 with 128,000 miles is very limited as it now stands probably the maximum value is less than $5,000 a very inexpensive toy for a play car. With the conversion I know I could sell it for around $3500.00 a $1,500 loss but much less than a new toy.
Distributor - this is kinda up in the air some say it has to be replaced with a vac advance distributaor and some say t does not, i will have to try the original first and if it don't work then replace it.
The biggest issue is the transmission with the kickdown, most information is split 50/50 but it appears the the computer does not control the transmission and is controlled by a cable that may have to custom made but certainly doable I think.
Digital dash - the digital (as another very attempt) will still be controlled by the ECM.
The total expenditures from Jegs (with the exception of the distributator and transmission) is less that $500.00
Please give me any comments or knowledge from your experiences.
You'll be dumping more hydrocarbons into the catalytic converter than it was designed for. Be prepared for the cat to melt down or set grass on fire. You might have to gut it, which will be yet another crime committed.
What about the air cleaner? Have a look at the air intake on a 5.2L Jeep Grand Cherokee. It looks like it would fit onto a 4bbl carb and might connect to the original air cleaner with some adaptation.
It'll be a parts car when you're finished with it.
The HEI distributor will spark the plugs if you hook up the power wire and nothing else. That doesn't mean it's working properly. It will function in a backup mode with no mechanical or vacuum advance. So yes, it will work and it won't work. Spend the $50 at a junkyard and get an HEI off an old pickup truck or something. It'll look just like the one you have but will have a vacuum solenoid.
Talk to Summit Racing. They'll probably have a cable and bracket to handle the TV cable. Oh, it's not a kickdown cable. It's a "throttle valve" cable. It handles shift points, shift firmness, and kickdown. If you drive with the cable missing or unadjusted, the transmission will burn up in minutes (learned this the hard way).
Summit also sells a controller for the torque converter lockup.
Someone responded to this in your last post.
$500 for parts, plus $1500 (?) depreciation. Add the TV cable, TCC controller, fuel pressure regulator, misc hardware.
It's your own car. Enjoy. Just please don't ever buy a ZR1.
In my state you would drive it ZERO miles, legally anyway, because you could not pas the emissions inspection, and could not have a legally licensed car. periods. So your resale value will flush right down the toilet with this backward modification.
Intake and carburetor verses crossfire injection. Don't have enough time to address the all of reasons why not to do this huge step backwards here and now... Sufise it to say TWO HUGE THUMBS DOWN ON THE WHOLE IDEA!
Whatever the value, it will be MUCH LOWER with you backwards modification to a carburetor. This drop in value doesn't even address that your pool of prospective buyers will be reduced to only the people who could pass their required emissions inspection and get it licensed. Many states, make that most states today will not pass or license this car after your backwards modification.
So you have stated that you are already upside down by $1500 on this car, and you want to nearly double that (not counting your time)? Wow, who could honestly suggest that this is a good idea?
FYI: I have done three (pre electronic fuel injection) carburetor to EFI conversion, and would NEVER suggest, anyone do that, let alone the backwards modification to a carburetor.
Good luck with your project, I would be willing to bet that by 2 years after your conversion is COMPLETE, you will be more than willing to admit that it WAS NOT a good idea.
(1) who cares about the value of the car. It's your car do what you will. If is of value to you to keep it stock then get it fixed. If you want to hot rod it or modify it, then do so. You can post a simple question and you'll always get different answers. If you live in an emissions strict state then it has to matter to you in order to get it to pass. Otherwise its your car.
(2) I guarantee you that there are a number of manifold and carb setups that will fit under the hood. I'm sure a tune port setup would fit under the hood too.
(3) the Value is in your eyes....
(4) If you go with a carb setup then you don't use an electronically controlled distributor (ECM controlled).
(5) I'm sure a 1984 car uses a TV / kick down cable for trans control. this is easily modified to work on any number of combinations. You need to start looking at some hot rod magazines, online resources. Its very common to swap out 700R4 transmissions into old cars ... IF you are going to run a carb setup for fuel then you stay with a 700R4 transmission. This is not a big issue at all, most any shop can get something to work here. I suspect that a TV cable out of a 92K1500 would almost work fine.
(6) I think the dash could be the biggest issue if its ECM controlled, but in 1984 there were very few cars that had any type of ECM control much less control over the dash. This should be very easy to call and find out about, as there are any number of shops that just do corvette work. I just don't think that in 1984 the ECM controlled very much at all, beyond maybe timing, fuel to some degree, and may have read engine temp and or O2 level to adjust for fuel.
Get over the hurdle and go buy the shop manuals for your car. Make some phone calls, ask around where you live.
A 79 Corvette would have a carb and distributor setup you could replicate. A TV cable for your transmission would be easy to do. You might make some real gains in power by going with a tuned port setup, but that's your call.
Once again your project cars value is what it worth to you. IF you have fun with it and it serves your interest then who cars what other do. There are plenty of people who $hit-canned the early fuel injection crap and went with a carb setup on various GM cars, because a number of them plain sucked. Now with hindsight its known that the tuned ports are good performers, and not to hard to setup, or even entire engine swaps...LT1 for an example would be great candidate for a vette. Most any of the 5.7 engines out of Z-28 or trans-am would also be good (fuel injected).
If that were my car, my only two concerns would be. (1) can I pass emissions if required (2) what kind of crap would I have to deal with to get the dash to work.
Outside of that everything else is just how you want to proceed. Either old school with a carb, or something new with a modern fuel injection setup.
Emmision controls have been around starting from 1968, Catalyst requirements
1974-75, so 1984 isn't exactly the beginning.
Bypassing emmision controls? Might as well tear out the ECM, and all the wiring that goes with it. You can't cherry-pick with the ECM. You did plan on rewiring the car, didn't you? Your digital dash?... I guess you'll replace everything with analog gages, 'cause non of the electronics will work.
Classifying it as a street rod maybe false thinking. IIRC that car must meet the emmission standards in effect at time of manufacture. Federal Law prohibits removing any type of emmision control device when it is operated on any public roadway, in any juristiction of the U.S. that receives Federal Highway Funds.
700R4: Electronic controls? yes and no. A little jewel call a VSS, wired to the cluster/ECM. You'll have to reverse engineer this system.
And you better consider what you're going to do with the fuel pump/delivery system. That carb you spec'd WILL NOT handle the pressure from that electronic pump!
Your $500 quote is laughable!
You'll spend that just to get the wares from JEGS. Then you'll spend at least another $2K in misc. parts and labor to get it to run.
My thought is it is probably missing quite a few pieces that will eventually become necessary.
The guy has had his heart set on this refit since he showed up. NO ONE, including someone who has already done the exact conversion and strongly advises against it, can talk this guy out of what is going to be a time-consuming, expensive mistake.
Again, this person places no value whatsoever on his own time, he has a huge misunderstanding of the complexity of this conversion, or he saved some poor mechanic's life at some point and is getting the payback. Let him go, but anyone who abets the effort shares the blame.
I've been restoring a 82,000 mile 1984 Corvette for over a year now. During this process, I've made it a point to know how everything works. The electrical system was hacked up pretty bad, so this was my primary concern. Unfortunately, the car ran very poorly, so I had to fix that first. I initially wanted to convert to carburation, but found the price-to-benefit ratio to be a negative value.
On the plus side:
The cluster only needs the ECM for fuel economy information. The rest of it will perform perfectly without the ECM.
On the negative (note that the ECM will be effectively dead):
The transmission TV cable (throttle valve system) can be adapted to a carb, but will be difficult to syncronise properly. Result- shift points and kickdown are never quite right.
The TCC (torque converter clutch: overdrive) is controlled electrically by the ECM. Most aftermarket TCC kits are designed for off-road use, and can be a real PITA on the street. Leaving the TCC disabled means reducing fuel economy considerably above 45 MPH. Top speed will also be reduced.
The stock distributor will not advance timing properly without the ECM. Improper timing advance = extremely poor performance. Early centrifugal+vacuum advance distributors will work, but not as well as the original system. Once again, it would lose some streetability.
Emissions will be higher, because affordable carbs just aren't as effecient as fuel injection PERIOD. Emissions go up and fuel economy goes down, resulting in a loss of performance and "fun factor".
I've been working on cars proffessionally for over a decade now. Once I realized just how much work was involved, and what I would lose, the decision was easy..... Fix The Crossfire. I later found that the fuel lines were severely corroded inside, severe enough to plug the fuel filter within a few days of replacement. I spent about $50 and about 5 hours bending and installing new fuel lines, and couldn't be happier. The '84 runs great, and gets 18-20 MPG (if I keep the pedal off the floor).
If the only reason you're bent on starting this project is a cracked manifold, here is a cheap alternative:
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it's still available Friday night, I'm going to buy it for a portingproject.....
None of you guys have mentioned that there are a number of engine swap harnesses out there that would allow you to swap something like a modern tuned port or Vortec style engine over into this car, which would include a new ECM. IF you determine which cars don't have electronic shift and only have to deal with TCC control then that would solve the shift business.
I realize that you have to know a great deal about car work to really tackle one of these jobs, so that's a given.
As far as a TV cable with a Carb. The principle of the TV cable adjustment is the same, whether its on a carb or fuel injected car. The brackets are very similar. I don't see it being a problem to adapt a bracket , or I believe B&M and others make one that would work.
Don't have first hand knowledge of the TCC kits...they may suck don't know. As stated there are kits out there. As I related swapping over a 700R4 into an older car (ie older than an 84 vette) is real common. I suspect there are a number of proven combinations for brackets and TCC control.
If you run a carb, you throw the electronic distributor in the garbage and get an old school HEI distributor (non ECM controlled)
I don't equate to emissions going up and performance going down.
You don't go down the road of a hybrid. You either go all the way with a carb or go all the way fuel injection. Its also clearly a given that fuel injection is by far cleaner, and more fuel efficient. Potentially more power depending on the system, due to fuel control. Meeting emissions requirements does not equal more power.
Yes its clear that fuel economy will not be improved by going to a carb, but I'm not sure the guy cares about that.
So the idea is that the ECM only drives the mileage "computer" on the dash. I personally don't think those things are accurate, and I could do without that. Don't know what the initial poster's preference is on this.
You can swap the intake, and install a carb, plus a non ECM distributor and have a very decent performing car. Look into what all the hot-rod guys are doing to make this happen.
Intake max $200.00 Carb $350 distributor $100 TCC control $75 ?
I don't agree with making this happen for $500 even if you do the work yourself. But its very clear that this is somewhat simple modification if one has basic mechanical skills.
So if you eliminate the distributor, and the fuel injection, and if you don't care if the fuel mileage display works, what's left that the ECM controls... just TCC? Which you can address.
I believe you could just remove the ECM all together, along with the stock intake and fuel injection. Install an aftermarket carb and matching intake, along with a old school HEI distributor and you would be in business. Yeah its a given there may be some like issues, like ign on at the distributor and TCC control. But these things are old school issues that have been out in the hot-rod community for some time.
Of course if you go old school, that opens the box to all kind of proven engine combinations that make good streetable power and run a carb, or even getting a Vortec 350 long block and use a carb for power.
Like I said... I think a tune port setup is the ticket here, but it depends on the owners ability and how much $$ he wants to apply.
If were to go to the trouble of going to a carb, I would change the cylinder heads to something like a Dart Iron Eagle setup, run a performer style dual plane if it will clear the hood or one of the GM LT1 old school dual plane intakes, and a matching carb. I would put that combination up against any cross fire. Carb setups are plenty "streetable" .
There are any number of vehicle setups that one could replicate with a GM 5.7 engine assembly. To be honest it would be near impossible to do this even simply for under around $700. And that's someone who knows how to do this work on their own.
I think you can easily get a clean running, very smooth drivable car by going carburetor. Will it pass emission for that year model vehicle...simply no!, will it outperform a cross-fire setup? maybe, Will it be more fuel efficient, no! Can someone do this with basic mechanical skills? yes. Is there value lost...yes if you want the car to be stock. Will your accessories function, yes. Are there many sources for modifications such as this, yes.
If I had a more modern vette would I change from fuel injection...no. Would I consider moving to a more modern fuel injection system over carb, yes. Why.. power. Are there plenty of parts available for such a swap over to a carb, yes.
If you want a stock vette, then of course you would not want to do this. You could easily make a swap like this work out and have a nice drivable car that performs very well.
Does a 84 vette run a mechanical fuel pump, if not then that would have to factor into a carb swap. I don't know what the fuel pressure requirements for a crossfire is but I would guess around 13 or lbs similar to a TBI. Of course with a carb you have to reduce that down to somewhere around 7lbs.
Of course I would make some other adjustments related to emission controls if I were to go carb setup. Yes you can make adjustments that actually make the car run better.
If you have pass emissions then you had better play the fuel injection game and see what your options are. If not then there exists a whole panacea of options.
Does doing a modification like this increase the value or even maintain the value, no. Unless you can repair the intake,you have a dead car on your hands, then something that runs sales better than something that does not.
Yeah, the C-4 is the red-head stepchild of the Vette family. I have a '95 Base Coupe. It has great 'AWE' factor with anybody out of the Corvette family but it's treated with much discrimination within the Corvette family.
That said, prices for C-4's are low. So if you're modding a C-4 that's not a Grand Sport or ZR-1 then you're not really doing any damage to the Vette family.
My '95 LT-1 will outrun almost any stock C-3 and deliver over 20 mpg. Name any C-3 that can do both. As for the C-5's, their prices are starting to soften and in a couple of years they will bottom out - then maybe they will be treated as badly as they treated the C-4's.
You should look at some of the Corvette forum message boards for ideas. As much as I hate to say it, Usenet is dying.
Hi Art, Hey, I wouldn't listen to the Corvette Nazi's too much. I have done exactly what you want to do (an 84 as well) and I love it. I don't know about emisions (exempt where I am) or resale value (don't care either) but I can tell it is very easy and relatively inexpensive too.
I have a performer rpm intake and speed demon carb and it all fits under the stock hood perfectly. I even fabed an air box that connects to the old hood ducts.
Any old HEI dizzy will work fine. I use a crank trigger set up though.
Yes, lots of brackets are available to adapt the existing TV cable ("kick down") and adjusting it perfectly is not an issue at all. To have torque converter lock-up and overdrive in 4'th gear (all thats needed) you just jumper 2 pins on the 700r4 connector.
My digital dash works just fine without the computer.
I had to change engines anyway so maybe not a "good idea" for you. Who is to say . . ? I'm extremely happy with mine anyway. It's 406ci with GMPP fast burn heads and their "hot" roller cam and the acceleration is just brutal now in comparison.
I realize this is an old discussion but if anyone wants info on x fire to c arb conversion, ive done it and i did it on a budget and am a year later st ill loving it. 13.66 1/4 mile, daily driver and still get 21 mpg highway. I still have the car and can supply part numbers and information to make you r conversion go smoother. snipped-for-privacy@gmail.com.
Just repaired an 82 Crossfire. Why would you go to the trouble of converting it to a carburetor. Easy to work on with the dual throttle body injection. Just use the assembly line diagnostic link with a paperclip and read the codes. It is such an easy system to tune. And, parts are cheap. And, don't get me wrong I do like carburetors for simplicity. But, don't think it is worth the effort to remove what already works.
i vi add a fuel pressure regulator to bring the ule pressure down will that work.im switching vow to a carburetor had an 82 with one.it worked just fine
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