Hi
just wonderng how many others have cross fire injection and the kind of problems they experince with them.
Thanx

 

You should get in contact with nsimmons. He is an expert on CFI and the ways it operates. PM or email him.

 

Also see Grumpy here on the board, he's quite familiar with CFI and has a recipe for upgrading the ECM to a '747.

I had CFI originally, it went away years ago in favor of TPI. If you want to keep CFI, buy or build a water manometer so you can balance the TBs...carb sticks won't do it accurately.

 

The crossfire itself is extremley simple. Its has less parts than a tpi engine, and is alot easier to keep running.

Theres only 2 real problems that are specificly related to this engine. First vaccum leaks. From around the top plate, and from the lower manifold bolts located in the plenum.

Though ive never had a problem, and ive had my intake off twice.

The other problems, which almost every hi mileage crossfire suffers from is un balanced throttle bodies. The 2 tbi's must be sync'd perfectly and open at the same time to prevent bogging, and hesitation.

When i purchased my car it had a slight hunt in the idle, I built a manometer and sync'd the tbi's and the idle became rock solid.

One other thing that can happen but isnt crossfire specific is a high idle, due to a bad coolant sensor, the car always thinks its cold. This is pretty common, but could affect any gm injection.

Other than that the injection is extremley reliable.

Visit the crossfire forum
www.crossfire.webhop.net

Under the TBI section a page or 2 back are pictures of my home made manometer, and instructions for syncing it.

 

I have a Crossfire. Haven't had any problems with it in over a year of ownership.
Rob

 

If my tbi's are out to sync would its also cause my car to rev at start up then idle normal and is it hard to sync the tbis or should I have if done by a pro consitering im new to this sorta thing.
thanx for all the input

 

what do you mean by rev, it supposed to idle high when its cold .

To balace the tbi's you basicly connect a water manometer to the center port on the tbi's and adjust each throttle blade until it pulls both tbis pull the same vacuum. A mano meter is just a piece of clear plastice tubbing stapled to a board, to make a long narrow U shape. Then you fill it up with water, leave one end open as a vent and hook the other end to the tbi. Its just a very sensitive vacuum gauge.

There complete instructions on the crossfire forum.

 

Hey thank for the fast reply. This may be stupid but where is the cross fire forum? consitering the my car may be sitting for some time because I took out second gear in the tranny and have to get it rebuilt. this may give me something to tinker with
thanks again

 

The link is www.crossfire.webhop.net

 

I see this is a very old post but maybe you still are visiting this site. I bought a high optioned 83 crossfire Z28 a couple of years ago that needed a little work. Was running like crap so I replaced every vaccuum line and it runs like a top, idles at 750 rpm. This is a car that I am going to restore somewhat in my spare time so I keep it covered and start it every month. This last month after starting it seemed to start kicking down from high idle somewhat and then goes back to high idle, somewhere between 1800 and 2000 and won't idle. It has not shown any check engine codes at all. It just seemed odd happening out of the blue like this. I tried cleaning the IAC which was a little gummed up but not bad. Did not change the high idle. Could the coolant temp sensor go bad and not throw a code? I would rather replace that than the IAC cause it is a lot cheaper. I really like the car besides all the people that don't. I agree with you that when they are tuned correctly they are a really smooth running engine. I was just getting ready to install a 5 speed before this happened. Any advice would be greatly appreciated.

 

Usually that's caused by the gasket between the intake base and the upper plate fails, creating a vacuum leak. You can check w/ a scan tool, IAC counts will go to zero as the ECM tries to reduce the engine speed.

 

Any updates?

 

Wow! Just happened to be on email when this popped up of which I had forgotten I had posted way back when. It ended up being a crack in a seam of the vacuum canister that is located on the firewall causing the leak. I sealed it up with some E6000 until I could replace it and it was good to go.....for while. It started again with an intermittent check engine light and I was feeling done chasing the issue as the engine had 134000 miles. I found an original 1972 300hp 350 from a Caprice with 50000 miles that runs awesome and I am in the process of the transplant right now. But...upon starting the removal of the CFI engine I had found the issue that was causing my leak was a cracked vacuum plug on the back of the passenger side TB, of which I am sure was the cause. So I am sure it would have ran fine if I had not pulled it out but I was committed at this point just about doubling my horsepower! So if you know anybody that is looking for a parts motor, let me know! Thanks for the reply and hope all is well!

 

what condition are the cfi parts ?

 

As I mentioned it was a complete running motor. In the process over the previous years I replaced bot IAC's, TPS, and other stuff I can't remember. The only thing I can remember that I took off the motor was the power steering pump pulley to put on a different pump and the fuel filter, bracket and line that I put on the replacement engine. Pretty much everything is there and was functioning before removal. I am at the point that I am connecting necessary wiring for the motor and will see if the engine will start without being connected to the computer. If it will run without it then the computer goes too.