hgpreston

Just bought my 12th Vette and it's an 82. Seems to run OK but still a little scared of the crossfire. Car is idling high, about 1100rpm in gear after warmed up. Any ideas on how to idle down or what's going on? Pics would be great if there is an adjustment point. All I've ever had was single carbed models and tunedport. Thanks for any help. :confused:

OatBoy

my freind just bought an 84, damn i hate crossfire. it's a stupid design. i can't help you :lol:

Desertdawg

What is wrong with the crossfire???? and how many have you owned???

Mine runs like a top, and I will buy a second one if I could afford it.

Here is another forum run by our own Twinnie( twin turbo) here on the CF.
http://www.crossfire.homeip.net:81/

You can get tons of info there, and lots of help tuning it if thats what it needs.

:seeya

Twin_Turbo

yeah, nothing wrong with the crossfire. It's not a stupid design since TBI is still used on many cars. The fact that the manifold sucks is not a problem that you can't overcome. For the rest it's just a small block like any other and the same go fast stuff applies.
Also, if you thought up this stupid designs in the end of the 70's you could have made a nice bundle out of it. The fact that with time there have come newer and better system doesn't mean the system is stupid, it's just old. Then it was nothing short of a small revolution. Commenting on stuff you don't know.. that's stupid.
But let's not get into that :) this topic tends to get out of hand

As for the high idle,

Check CTS, TPS, MAP and check for vacuum leaks around the lid.
There's no adjustment for the idle itself, it's controlled by the ECM but you can adjust the minimum air setting. However, it's unlikely it's that unless the system has been tampered with (TB's removed from lid), or the TB shafts are worn and leaking. If all else fails you may need to reset minimum air. The way to set it is a bit of a PITA because you have to balance the TB's and the adjustment points (idle stop screws) are double (both TB's have one) so you'll have to work from 1 TB as a reference and then use the synchro screw. The complete procedure is omn the above mentioned site.

Oh, and the :81 addition is no longer necessary.
http://www.crossfire.homeip.net will work too now that the ISP has released port 80 again :)

Marck

CWUin82

No need to be afraid of your crossfire. Once you've become familiar with it you'll love it. It's not the white elephant that some believe it is. As was said above it was quite a piece of technology for its time. Any time there is new technology, you will find faults with it.
Ever read about the early fuelie cars and how many felt they couldn't be tuned? Some of these cars had the fuel injection systems replaced with carbs to solve the problem. Try to buy one of these systems today and be prepared to offer your first born in order to get it.
I'd start with the easy things first. Check for vacuum leaks. Also see the crossfire site. I don't think there is anyplace on the web like it.

Wrecked82

175,000 miles on my crossfire and not ONE problem related to crossfire setup.



[Modified by Larry82, 7:50 AM 3/15/2003]

Roadster71

There's nothing wrong with crossfire, it just doesn't lend itself to hotrodding. Back in 82 it was the best there was.
My wife's 82 runs sweet all day long and gets 23-25 mpg to boot.
As far as idle is concerned the first thing I would check is for vacum leaks. Look at all the hoses and snug up any intake bolts you can get at for a start.
Enjoy the car, there the most comfortable c3 to cruise in, refined. :yesnod:

Pete Z

I'm driving my stock 82 daily for more then a year now,never had any problems.
Great car,and the only fuel injected C3 ever made by Chevrolet..... :cool:

Ironcross

Adjust the TPS sensor and it will probably fix the problem. Contary to some ideas as to the worth of a Crossfire Injection, it makes a very good racing application. If you want more power just add a GM 151 camshaft to the engine. :thumbs:

hunt4cleanair

I read elsewhere crossfire is great for cruising but don't expect to get much performance out of it...true?

Ironcross

False, the camshaft is very poor, change it. And the throttle bodies are easy to modify. Another problem with crossfire engines is NO compression, not the injection :thumbs:

Astro7

Someone on the Forum (a GM mechanic I belive) told me to change the oxygen sensor to help with the high idle problem. I did and it worked like a charm. That has been the only problem I've had with the crossfire (knock on wood).

LAvetteman

One thing I learned during my time here on the forum. Don't say ANYTHING slightly negative about crossfire setups. There are alot of die hard fans here that don't want to hear it much. ;) :lol:

Desertdawg

:thumbs:

Jim Martley2

I'm with Desertdawg, I'm happy with mine!!!

:thumbs:

OatBoy

i have owned none but worked on two, and i just think its not an intelligent design, TPI added 25hp when they instituted it. they do respond fairly well to tuning, but i just don't like the design. i realize that was a poor time in car performance history and i'd imagine you could hop them up just as easily as any other engine, i dunno, they scare me or something. Sorry to **** off the cross-fire people :D


[Modified by OatBoy, 12:03 AM 3/17/2003]

Ironcross

Crossfire injection is actually a good choice for racing. The problem with 84`s is no power. Insert a GM 151 hydraulic camshaft in the engine and it will do wonders for the car. The cam is from 65/67 327`s 350 HP engine. You can leave the compression alone and it will improve the car tremendously. The 84`s were probably one of the slowest Vettes built at only 215 HP. :thumbs: The 75`s were the 165 HP, Another slow Vette similar to the 84`s in performance. ZERO :lol: :lol:


[Modified by Ironcross, 2:17 AM 3/17/2003]

killain

In the front of both throttle bodies is the idle air control valves. Unplug and clean both of these with cleaner and reinstall. They could be dirty and or out of adjustment. There are a number of adjustments that a 'Cross-Fire gets that regulates the idle, but I don't have the room here to go over all of them.

Desertdawg

Ummm 165 HP in 1976....I think?????

Twin_Turbo

The TB's aren't that easy to modify. Yes you can knife edge the throttle plates, yes you can thin the shaft. But you can't overbore them very easily. The castings are thin and above 2" you need to sleeve the housing.

The compression is actually quite good at around 9:1. The crossfire has the TRW 464664 L82 forged flat top pistons, not the 4 relief L48 ones. If you slap on a set of nice closed chamber heads you have quite good compression and you will be able to run a nice duration cam too. The only major problem is the intake but id your emissions testing isn't very stringent you can swap to another cross ram manifold and mill your own top plate to accept the TB's. Examples are: Edelbrock STR-10, SY-1, Offenhauser CrossRam (copy of OEM GM crossram)