converting my 82 cross fire

[hotshotzny]

this may sound crazy but i have had a couple people suggest converting my poor running cross fire injection to a regular intake and carbureting it . has anyone ever done this or have any input on this, my original plan was to swap out the motor with a crate engine but i see how this could be a much cheaper way to make it run better

 

[6880 Mike]

Lots of folks have dumped the Crossfire for carb. Why not keep the Crossfire and have it professionally tuned? Nothing wrong with the Crossfire when it's tuned.

 

[hotshotzny]

Lots of folks have dumped the Crossfire for carb. Why not keep the Crossfire and have it professionally tuned? Nothing wrong with the Crossfire when it's tuned.

well to be perfectly honest there is one person around here who knows anything about the crossfire and getting your car in his shop is almost impossible

and i think he wants a piece of my liver as payment.

 

[KANE]

well to be perfectly honest there is one person around here who knows anything about the crossfire and getting your car in his shop is almost impossible

and i think he wants a piece of my liver as payment.

Sounds like it is time to teach yourself! Why not?

 

[JohnGrawcock]

Assuming you haven't changed the heads and CAM the only thing you'll achieve by going to a carb is a 50% reduction in fuel mileage. Performance will not be significantly increased.

Crossfire is just a simple Throttle Body Injection (TBI) system. TBI is the easiest EFI system to work on and was used on many vehicles throughout the 80's and 90's. The only difference between it any other TBI (those used on Chevy trucks for example) is the fact that there are two sencronized throttle bodies rather than a single unit. Since both injectors actually receive the same firing pulse even the fact that there are two is irrelevant. In other words, anyone competent at working with the most basic EFI system should be able to help you with your Crossfire.

Or better yet, tell us what it's doing. We can probably help you sort it out.

 

[pbcanney]

I fully understand the idea of ripping the crossfire out and putting in a standard 4bbl set up.

Its easy to get lost trying to figure out the mysteries of the x fire, distributor and all those wires.

it's like "give me a fighting chance here" if you've never worked on anything thats computer controlled.

when I priced a stock replacement for my 81, the prices were close to $1000. (the previous owner had ripped the original out years ago)

It's hard to say "no" to a $250 carburetor and $150 manifold vs paying someone who probably DOESN'T know anything about the x-fire to learn on your dime/time.

the 82 Corvette is a cool car to drive.
but not if it runs like a beat up Biscayne wagon.

 

[ironmoo]

I feel for you. Go with your gut, it's your car/time/money. Me, I'm keeping the car stock and go for the tuning route. I plan to go roller rockers and '85 fuel pump first.
But believe me I've been tempted to pull the motor, store it aside and pop in a crate engine.
But the time and money keeps me going this route.
Have you thought about the CrossRam manfold? You may know these already but just in case:

http://www.x-ram.com/
http://www.crossfireinjection.net/


-Moo

 

[Glensgages]

Once you remove the distributor (which I don't think would-be compatible without the computer) and intake manifold with injectors, it is a simple small-block Chevy that will respond to any changes you make:
I hope that in the near future I'll be able to replace my Cross-Fire induction with an RPM Air Gap intake & a Holley 650 mechanical-secondary carb, along-with aluminum 64cc heads, 270H cam, and headers.

This should result in an 'honest' 325 (or-more) HP at the crankshaft

 

[hotshotzny]

I feel for you. Go with your gut, it's your car/time/money. Me, I'm keeping the car stock and go for the tuning route. I plan to go roller rockers and '85 fuel pump first.
But believe me I've been tempted to pull the motor, store it aside and pop in a crate engine.
But the time and money keeps me going this route.
Have you thought about the CrossRam manfold? You may know these already but just in case:

http://www.x-ram.com/
http://www.crossfireinjection.net/


-Moo

for some odd reason i am hell bent on keeping this thing stock, the 85 fuel pump is on its way along with a couple other items im gonna need if none of this works its back to the drawing board

i had never seen the x-ram manifold before so that has my interest i must say, the other site i have been on and i am goin with the adjustment tools for fuel pressure wish me luck

 

[cinci5]

this may sound crazy but i have had a couple people suggest converting my poor running cross fire injection to a regular intake and carbureting it . has anyone ever done this or have any input on this, my original plan was to swap out the motor with a crate engine but i see how this could be a much cheaper way to make it run better

Keep the crossfire it's not to hard to figure out once you dig in.

 

[minifridge1138]

My 1982 has a 4 bbl Holley.
The previous owner did the conversion poorly, so i've had to redo most of his work.

After you replace the distributor, intake + carb, and fuel pump, it IS just a small block chevy.

BUT, you'll have a mess of other problems:
The engine is full of unused wiring harnesses, the torque converter will not lock, your warning lights go up like a Christmas tree, auxiliary fan won't come on, you loose the low end torque, and some other stuff.

The best part is that you fail most emissions tests.

I'd do my best to get the Crossfire tuned (it is a modified '69 Z-28 dual carb manifold so it has power). If that failed, i'd look to upgrade to something modern, not to something older. I've heard that an '85 fuel pump and some intake porting really help the car wake up. Throw in a 3.55 rear end and you'll have awesome, RELIABLE performance.

 

[geekinavette]

Yay another CrossFire discussion! :gap

for some odd reason i am hell bent on keeping this thing stock, the 85 fuel pump is on its way along with a couple other items im gonna need if none of this works its back to the drawing board

i had never seen the x-ram manifold before so that has my interest i must say, the other site i have been on and i am goin with the adjustment tools for fuel pressure wish me luck

There is NOTHING "odd" about wanting to keep your '82 stock! With that decision made....

The 85 fuel pump IS a worthwhile "upgrade"...but unless your original is failing, it ain't gonna fix anything. My own experience has been that the fuel pump either works, or doesn't...not usually "in between" somewhere (but hey anything's possible). Definitely check out the fuel pressure...these things (well any EFI system really) rely heavily on having correct fuel pressure.

As for the X-Ram...ahh well everyone has their own opinion. Mine...piece of garbage. You couldn't pay me to put one of those things on my car. Besides...you NEED to find out why it is running poorly in the first place before you even consider a major modification like that. You could very possibly go through a TON of work just to find out it still runs like crapola.

It would help to be a little more descriptive than just "poor running". Can you describe what it is doing (or not doing)?

As much history as you can provide will be helpful also. Mileage? Prior repairs/modifications? Symptoms?

What does your tool inventory look like?

Bill

 

[hotshotzny]

Yay another CrossFire discussion! :gap




There is NOTHING "odd" about wanting to keep your '82 stock! With that decision made....

The 85 fuel pump IS a worthwhile "upgrade"...but unless your original is failing, it ain't gonna fix anything. My own experience has been that the fuel pump either works, or doesn't...not usually "in between" somewhere (but hey anything's possible). Definitely check out the fuel pressure...these things (well any EFI system really) rely heavily on having correct fuel pressure.

As for the X-Ram...ahh well everyone has their own opinion. Mine...piece of garbage. You couldn't pay me to put one of those things on my car. Besides...you NEED to find out why it is running poorly in the first place before you even consider a major modification like that. You could very possibly go through a TON of work just to find out it still runs like crapola.

It would help to be a little more descriptive than just "poor running". Can you describe what it is doing (or not doing)?

As much history as you can provide will be helpful also. Mileage? Prior repairs/modifications? Symptoms?

What does your tool inventory look like?

Bill

yea i am far away from even thinking about modifying anything on this thing... so far just about everything obvious has been changed, fuel filter, plugs, wires, cap, rotor, cts sensor, rebuilt both throttle bodies, and i made a HUGE improvemnet over the way it was running, but i honestly think it is possesed like i said...2 days ago i took it to the store and barely made it home, the next day i took it out and it ran like a raped ape, same as tonight , ran better than ever for a few miles them started sputtering and starving for fuel, the obvious thought would be its got bad gas, but it is doing the same thing it did last fall and that was with new gas clean filter etc..... but on its worst day it hesiatates hard upon acceleration then gives a little sputter and takes off, as if it just isnt gettiing enough fuel, all i can think is fuel pressure at this point, everything else seems to be functioning right...as far as tools, i have what some people call a mild case of ocd, rather than borrow something i buy it and use it once, so i have a pretty good set up including a 4 post lift so im ready to race!!

 

[geekinavette]

First two thoughts...

1- were the throttle bodies properly synchronized?

2 - verify proper Check Engine light operation and check for codes?

 

[minifridge1138]

It sounds like a fuel issue, too little or too much. I'd check the fuel pressure.
The sender in the tank has a strainer. It is possible that that is clogged. Also, the car came with a fuel bladder. I've heard of them going bad. They can rot and clog things, or they can collapse and restrict flow. I would definitely double check to make sure the throttle bodies are synchronized.

It could also be a timing issue (possible, but not very likely). Do you have it set at 6* BTDC? Does the stock distributor have a vacuum advance? If so, is it operating correctly?

Good Luck!

 

[geekinavette]

'82 in stock form does not have a vacuum advance distributor...all ECM controlled.

 

[hotshotzny]

First two thoughts...

1- were the throttle bodies properly synchronized?

2 - verify proper Check Engine light operation and check for codes?

the check engine light does work cause when its running real bad the light does come on for a couple seconds... but no codes are showing

as far as synching the throttle bodies i am still trying to find a competent mechanic to do that

 

[geekinavette]

Well that's a big red flag right there...if the CEL turns on when the engine is running, it must have a code stored. You did the jumper pins A and B of the ALDL connector? If that light is turning on (with engine running), and you only get a code 12...then you got ECM problems!

Synchronizing the TB's isn't difficult, and you can do it with a home-made manometer. There's a decent article by one of the magazines...can't recall which one right now...have to try to dig that up again. That's not causing the intermittent nature of your engine woes though...but the ECM most certainly could be. Once it is consistent (be it bad, good or somewhere in the middle) THEN work on synchronizing the TB's).

 

[82ColEd]

Here ya go:
http://www.corvettefever.com/techarticles/4688_chevrolet_corvette_efi_system_tuning/index.html

Btw, i'm with the other guys: Tell them what the problem is, and either Geek or Pete will jump on help you out ! They help me all the time (sorta ), and i know next to nothing about engines..


-Stefan

 

[geekinavette]

Where'd the rest of that article go? I thought it had a good description of actually balancing the TBs?