TBI Throttle Body Injection discussion and questions. L03/CFI tech and other performance enhancements.

Crossfire FI

Thread Tools
 
Search this Thread
 
Old Sep 20, 2002 | 08:42 PM
  #1  
306Stang's Avatar
Thread Starter
Junior Member
 
Joined: Sep 2002
Posts: 10
Likes: 0
From: Waco, TX
Crossfire FI

I just purchased an '82 Z28 pace car, it has a 305 w/ crossfire fuel injection. The car has been sitting for some time, about 6-8 months, and it runs really rough. I'm wanting to know if it will be worth it to clean up the crossfire, or just pull it off, and put on a carb/intake ... ? I plan on keeping anything I pull off, but I am looking to make it run better.

Currently, if you go anywhere over half throttle, it bogs down. It does have Edelbrock headers, 3" exhaust, aftermarket Y-pipe, flowmaster, 4.10's and a 6-speed.

Any help y'all can give me, would be greatly appreciated. I'm more of a Mustang man, and both my Mustang's are carb'ed.

Rob
Reply
Old Sep 21, 2002 | 10:08 AM
  #2  
jase's Avatar
Member
 
Joined: Jan 2001
Posts: 288
Likes: 0
From: west Point MS USA
Being a true pace car,I would try to keep it orginal as much as possible.There is a web site for cross-fire cars that can help you.Ionced owned a 1983transam with cross-fire butI changed it out to a carb because of the computer went crazy.
Reply
Old Sep 21, 2002 | 11:38 AM
  #3  
306Stang's Avatar
Thread Starter
Junior Member
 
Joined: Sep 2002
Posts: 10
Likes: 0
From: Waco, TX
Yea, I would like to keep it as original as possible. I want to make it a better daily driver tho. Like I said, anything that comes off, is getting cleaned up, and stored, that way I can still have all the original pieces.

Do you know the website for the crossfire injection stuff?

Rob
Reply
Old Sep 21, 2002 | 02:46 PM
  #4  
Tom 400 CFI's Avatar
Supreme Member
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Oct 2000
Posts: 3,176
Likes: 787
From: Park City, UT
Car: '92 Corvette, '89 1/2-a-'Vette
Engine: LT1, L400
Transmission: ZF6, T5
Axle/Gears: 3.45, 3.31
This is the website:

https://www.crossfire.homeip.net/cft...artdefault.asp

As for your car, check the fuel presure first! This is one of the most major issues with these cars; the stock fuel pumps suck.

Then check for vacuum leaks at the plenum lid gasket. Actually, look for vacuum leaks everywhere, but the unique-to-this-car place for vacuum leaks is the plenum lid gasket.

Then check and re-balance your throttle bodys. How to here:

https://www.crossfire.homeip.net/cft...hrottle+Bodies

read the LAST post by Bobwhite84. The first post by Dominic is irrelevent to your stock set up. (He performed mods to his TB's that change the way he must balance his TB's)

After that, general tune up stuff and it should run great! You should see low 15 sec 1/4 mile times with a good running, STOCK CFI car.
Attached Thumbnails Crossfire FI-trans-am3.jpg  

Last edited by Tom 400 CFI; Sep 21, 2002 at 02:49 PM.
Reply
Old Sep 21, 2002 | 02:50 PM
  #5  
Jokerman's Avatar
Senior Member
 
Joined: Jun 2002
Posts: 595
Likes: 0
From: Schaumburg, Illinois
Engine: slowtacular L03 305
Transmission: slushem 700r4
I just ran across an 83 z28 crossfire today at a car show. neat setup, i think i would just go ahead and keep it just for the freak show factor of it. Just don't expect to get parts from GM as they have discontinued alot if not all of the cfi parts.
Reply
Old Sep 21, 2002 | 05:31 PM
  #6  
Tom 400 CFI's Avatar
Supreme Member
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Oct 2000
Posts: 3,176
Likes: 787
From: Park City, UT
Car: '92 Corvette, '89 1/2-a-'Vette
Engine: LT1, L400
Transmission: ZF6, T5
Axle/Gears: 3.45, 3.31
Originally posted by Jokerman
Just don't expect to get parts from GM as they have discontinued alot if not all of the cfi parts.
Doesn't matter. Non of the CFI-specific parts will ever need to be replaced, except for gaskets, and they are easily available. The parts that wear (injectors, FPR, etc) are all common to other engines, and are readily available.
Reply
Old Sep 21, 2002 | 10:05 PM
  #7  
306Stang's Avatar
Thread Starter
Junior Member
 
Joined: Sep 2002
Posts: 10
Likes: 0
From: Waco, TX
Originally posted by Tom 400 CFI
This is the website:

https://www.crossfire.homeip.net/cft...artdefault.asp

As for your car, check the fuel presure first! This is one of the most major issues with these cars; the stock fuel pumps suck.

Then check for vacuum leaks at the plenum lid gasket. Actually, look for vacuum leaks everywhere, but the unique-to-this-car place for vacuum leaks is the plenum lid gasket.

Then check and re-balance your throttle bodys. How to here:

https://www.crossfire.homeip.net/cft...hrottle+Bodies

read the LAST post by Bobwhite84. The first post by Dominic is irrelevent to your stock set up. (He performed mods to his TB's that change the way he must balance his TB's)

After that, general tune up stuff and it should run great! You should see low 15 sec 1/4 mile times with a good running, STOCK CFI car.
Well, currently the car has done a best of 15.2 at like 86 or 88 mph. That's with the 6-spd and 4.10's.

I read that post, that wouldnt be hard to do, the throttle body's were adjusted about a month before the car was parked, by the person I bought it from (GM mechanic), but the car ended up sitting for 6 months.

Bob states "put the car in drive" ... Doesn't work too well with a manual transmission. I think I might have some dirty injectors, I went out and raced it last night, and it is actually running a lot better now, just blew all the crap out of it. I figure clean the injectors, new filter, maybe plugs/wires/cap and it should run/idle better.
Reply
Old Sep 23, 2002 | 09:30 AM
  #8  
Tom 400 CFI's Avatar
Supreme Member
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Oct 2000
Posts: 3,176
Likes: 787
From: Park City, UT
Car: '92 Corvette, '89 1/2-a-'Vette
Engine: LT1, L400
Transmission: ZF6, T5
Axle/Gears: 3.45, 3.31
Whoops!

306stang, Sorry, but I didn't rear your post carefully enough. I hate it when people do that, so I'm sorry.

With your headers, gears, and a manual, you should be running mid 14's. Way back when my car was mostly stock, (I've typed this story too many times now) My TA ran a 14.5 @ 95. Mods at that time were: 5 Speed, 3:45 gear, Edelbrock headers, SLP 3" cat back, w/'86 and newer cat, raised fuel pressure, advanced timing, 160 T-stat, and electric fan. That's pretty good IMO, but I believe any stockish CFI car shoudl do as well.

Currently I have a friend that has an '84 CFI (350) Vette, auto. His mods are bored TB's, raised FP, hand ported intake, Advanced timing, a converter, and a holow cat. That's it. He is currently running 14.7x's....at 4500' elevation! That is high 13's at sea level!

Tuning is what does it! A well tuned CFI will go pretty well. I'm glad your blow-out session was so successful! lol. Sounds like you should run 'er a little more, and then make the checks I suggested. Though I'd say you can forget about the throttle plate balancing, if it was recently done. I never touch mine, except AFTER I have R&R'd them for something. Then I check them. Nothing should change as long as they stay bolted to that plenum lid.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
NZKnight
Tech / General Engine
6
Oct 15, 2015 02:47 PM
Tweeks25
Electronics
0
Sep 17, 2015 08:04 AM
edoff13
TBI
10
Sep 11, 2015 03:55 AM
3rdgenparts
Firebirds for Sale
0
Aug 6, 2015 09:03 AM




All times are GMT -5. The time now is 04:24 AM.