How good are these engines,did they have problems?

 

The Crossfire setup was problematic when new, and a good many of them (in Vette and F-body applications) have been replaced with carbs. That said, there are plenty of TBI specialists who have gotten decent results with them. Turbo City is one of them.

 

I am just shy of 100,000 miles on mine with never any problems. Very reliable and very good gas mileage with the 700R4.

 

Keep in mind tuned properly, they get great gas mileage for a twenty-six year old car, 18 to 20 mpg and run great for a long time without needing service on the injectors.

 

I had an '84 Vette with the same TBI set up. While the car had its share of problems over the 60K miles I put on it, the TBI ran flawlessly during the 5 years I owned it. I think the TBI problems are exaggerated.

 

I have one and after fixing the "known" issues, it runs great. So good, I've deferred putting the TPI setup on that I purchased when I first got it.

The biggest problem is the knowledge base is very limited because the production years were so few. It was quickly replaced by TPI, which is certainly better but if you either have a tech that knows cross fire or you're willing to do a little homework, it's a great setup.

 

I agree with the previous posts, my 82 has not been a pain. It seems many of the issues have been worked out since the motor was produced. The crossfire forum has a vast amount of information available. One of the most common problems with the motor is vacuum leaks, the crossfire setup seems particularly sensitive to them. Usually replacing the intake manifold gasket solves the problem.
Just my 2c,
Tom

 

The CFI is prone to vaccum leaks and are very vaccum sensitive. If the TBI units get out of balance the car will run awfull. The TBI units after a while will develop leaks at the throttle shafts. A simple fix for the leaks at the throttle shafts is to have them bushed. I did the research and there is an article I will post the link to that will tell you step by step how to tune the car.

CFI got a bad rap because when they were introduced, no one knew how to work on them including dealership mechanics. If you understand the system, it is realatively simple to work on and will run well as designed for many years.

If you are in to modifying from stock the CFI has limited capability in that area but with a little trial and error they can be modified to a degree. The biggest problem is the flow. The manifold needs to be opened up, the heads and cam are pathetic on a stock CFI car. You have to becarefull in picking your new set up because of the limited computer capabilities. However if you get in to the programming, you can produce a modfied car that will run well with good power.

I have decided to mod my CFI. I am going with a ported intake, a Crane 2040 Cam and 180CC heads with 72CC chambers and flat top pistons (.030 over), bored out TBI units to 2", 2.5" exhaust, headers and the stock computer. The compression needs to stay under 10. This should produce around 300-325 Hp with out any computer mods. I am also going to swap the rearend gear to a 3.83 which should be fine with the 700R4 tranny (overdrive for the Highway) I have modified the air intake so that it gets fresh air at all times through the hood plenum and I have put a chip in the car that makes minimal differance.

The link for tunning the CFI:

http://www.corvettefever.com/techart...ing/index.html

Good luck have fun thats what its all about.

 

I don't have an 82 but my 84 is basically the same engine. It idled all over the place when I got it. Mine had most of the the upper manifold bolts loose, several so much so that I could turn them w/my fingers. Also found a couple minor vacuum leaks too. Then I removed the IAC motors from the TB's and cleaned those and the passages w/carb cleaner as they were pretty dirty. After all that it has idled and run fine for several years now.

As an additional note, I also had another driveability issue occur a few months after I got the car. Turned out the O2 sensor was crudded up and reacting so slowly that is was causing the computer to fall back into the open loop, "pre-canned programming" normally used while the engine is cold and until the O2 sensor is heated and ready to go. The O2 sensor was only $20 and after replacing it the computer stayed closed loop and car responded and smelled much better because it wasn't running sloppy rich all the time.

FWIW. Good Luck!

 

no problems with my car .i like the gas mpg .its a good driver .if you want a drag racer i would look else were.

 

When I bought my 82 I didn't know alot about the CFI but thanks to the forum it wasn't hard to get it running great. It had the usual intake leak, easy fix ! I have 114k on it and it's still running strong. A very reliable car that my wife and I are afraid to drive a couple hundred miles a day. I'm getting 25mpg buy the way.

 

They have a bad reputation, but if properly maintained are very reliable.

 

I love these threads. Crossfire fans defend them, carb guys trash them and neither group will admit that each has a place.

I had one 82 for a short period of time and will never have another one because I don't care to learn how to keep the cf system working right. I admit to being old school and like the challenge of tuning a carb and have no desire to learn fuel inj. I think guys like me are the ones who give cf a bad rap.

My answer to your question:

The engines are fine if you want to leave it stock and learn something about an obsolete system. It can be a challenge but you may enjoy it like bluesilver does. If you want more power, you will be money ahead to aviod the crossfire.

 

I'm buying another Corvette to go with my 1972 and my 1990. It's a 1982 with the Cross-Fire Injection system. Only the passenger side throttle body is working, no fuel coming out of the drivers side throttle body. Any ideas as to what's wrong? Also, when it's running it's very, very rich. The previous owner replaced the computer with no change. I'm thinking the intake manifold is leaking and the computer is throwing more fuel at the problem. The non working throttle body I don't know.

 

Well, I've had both carbed and CrossFire engines in Corvettes. Both are fine, as long as they are not damaged and are maintained properly. I don't know that TBI is any more (or less) complicated than a carb; they are just different ways of obtaining a good fuel mixture. The TBI requires an ECU and O2 sensor to manage it. A carb requires being set up properly to provide proper fuel/air mix throughout its operating range.

I had a new '84 with CFI and it performed fine. If you want to upgrade the engine, it's more difficult than upgrading a carbed engine. But, it can be done with proper advice and components.

TBI idles more smoothly than almost any carb. It will start better, as the ECU compensates for temp changes and manages engine speed. Carb choke and fast/curb idle speed adjustments can be problematic. TBI will always provide equal or better fuel mileage results, as long as it is properly maintained. The main reason that '82/84 CFI cars get significantly better mileage is that they came with an overdrive transmission which can provide up to 30% reduction in fuel usage. But, my '71 SB now has a 700R4 and a Lar's-tuned carb, and I still can't match the fuel efficiency of my '84. Computers just manage fuel mixture better than even the best tuned carbs.

Other than that, either type of induction system will have its good points and not so good points. Their maintenance care will be different, because of their integration with other components that can fail, also {ie, throttle position sensor (TPS), mass airflow sensor (MAF), temp sensors, O2 sensor, etc}. When any of those items fail, the engine will generally run terrible. But, the ECU also will provide 'fault codes' that will guide you to the area of the problem. I'd like to see if someone has a carbed engine that will do that. [Well, I guess the '81 C3 is the exception to that concept. It was carbed and also had an early version ECU with OBD-1 diagnostics.]

Anyway, I wouldn't shy away from either system. But, if I wanted to modify the engine for better performance, I'd opt for the carbed version, as there are limited resources for modifying/upgrading the TBI system. They are available...just not as plentiful.

Hope some of that is helpful to you.

 

Any idea on why one throttle body is working and the other is dry?

 

Check the voltage going to the dry side on the injector. If you're getting a reading it's either the injector itself or the fuel line from one side to the other is blocked.

Best thing I ever did was watch the tuning video, purchase a nanometer, clean the injectors and replace the base gaskets....over six years that I've owned it now....runs absolutely great.

 

Was it running rich due to the base gaskets leaking?

 

Check the 2 TBI fuses first.

Flip the wires on the injectors. If the other one starts working its the injector (no likely) or the electrical.

If it does the same thing its probably the fuel pump. If the fuel pump does not deliver enough fuel it will run through the first TBI and into the second leaving one dry.

If you buy one of these cars. First thing to do is change the fuel pump. Second is to change the lid gasket. It will solve 95% of all the problems.

 

Just to give you a bit more of an explanation:

Fuel pump (electric) delivers between 9-13 psi to the driver side TBI. The driver side TBI has a regulator spring in it, the passenger side does not. That spring is factory adjusted to deliver about 12 psi to both injectors. When the pump goes it will deliver less then 9 psi. The spring is not capable of increasing fuel pressure it can only limit it so when there is not enough pressure the gas flows right through the first TBI into the second which has the return fuel line. With low pressure only one of the two TBI's will take fuel because there is not enough pressure for both to take fuel.