[bgetz]

HELP !
1984 Camaro Z28 with Crossfire injection auto trans. It loads up with fuel if you don't keep the RPM's up. I actually locked up the motor 1 time.
Shft points are very firm. The wife loves the car..... How can I get it to stop loading itself up with FUEL to the point it stalls out in the middle of the road?

 

[novaderrik]

the easy answer would be to get rid of the cease fire setup and put either a carb or a normal TBI on it.
now that i got that out of the way, i'll say to check over all the sensors and what not.
make sure the injectors are clean and working properly. check the fuel pressure.

that is kind of an oddball setup, and no one really wants to screw around with them. but it should just be a matter of getting the right signals to the computer, and having the right amount of fuel pressure.

 

[Rodder]

I vaguely remember something about these having problems with leaky cold start injectors. But yeah, the best thing to do is ditch the CeaseFire and upgrade to TPI or a carb. Or ditch the whole engine and upgrade to an LSX :-D

 

[wiskeesour]

Most ppl do not like crossfire cuz they dont understand it. Its kinda like a rochester, works wonderful, when its working. I personally would like to understand it better. BUT, the more problematic thing on this setup is injectors not grounded properly. check that.

 

[Lost in the 60's]

I don't recall a TBI having a cold start injector....that is a TPI item.
It may be the temp sending unit that sends the signal to the computer. If it is indicating a cold condition continually, then the computer will compensate by feeding more fuel. My first suggestion is to follow the electric wires from all the sensors and TBI units to insure none of them have worn thru the insulation and are shorting out or broken. Then check the fault codes with a OBD reader. You may need to reset the codes if there are too many to start with and let it store a recent set.

 

[ZZ_430]

Yeah, take the air cleaner off and start the engine, looking at each injector spray pattern. You shouldn't see big droplets.

Then turn off the engine and check them again for any dripping. It's not unusual for those to go bad.

But, the only real way to diagnose it, is scanning it. The coolant temp sensor would be one of the first things to check using the scan tool.

They are also notorious for vacuum leaks between the plenum halves which would make it go rich because the ECM thinks it's under load.

 

[Everett#2390]

Thanks, Don for the tip of the plenum. I have a neighbor with a Crossfire Corvette having a high idle issue. I told him to look for a vacuum leak, a large one and he said he couldn't find any.

 

[dnult]

I haven't heard too many good things said about the cease fire setup. Before you spend a bunch of money on it, consider changing it out as others have said.

If this were a TPI or other non-TBI setup, I'd say to check the pressure regulator. I've seen those go bad and dump raw fuel down the vauum line. I suppose a TBI setup could have the same issue -- a leak in the regulator dumping raw fuel into the motor. Not sure how you can check for that except perhaps with a pressure test. Put a pressure guage on it, turn on the key (or start it if you have to) to get the pressure up. Then kill the ignition and see if the pressure holds up or bleeds down. Perhaps someone else has another tip for verifying the regulator.

 

[kustomwerker]

tbi setups hold very little pressure in the throttlebody as far as i know...thats why theres no pressure tap externally on the line...(i would think)on tbi, the regulator is under spring pressure, with no vacuum line...once the pressure passes 7-13 lbs depending on reg setting, the poppet valve lifts off, and fuel is diverted to the return line...unfortunately, i`m not sure that this is the case with a crossfire, as i`ve never had the displeasure of working on one of them...lol..

 

[72Tugboat]

This might help:
http://winaldl.joby.se/

Good Luck!

 

[BonzoHansen]

CFI runs fine. It was better then those feedback q-jets. It’s usually the knucklehead with the wrench that messes it up. Troubleshooting is no different from any other kind of TBI/EFI setup. It isn’t a space ship. We fear the unknown. :noway:

But there is some good info here. I’d go to town with a can of carb cleaner & look for vacuum leaks 1st. Indeed look at it idling with the air cleaner off. Turn key off & look for drips. Scan codes (no check engine light)? To check fuel PSI, you have to tap the feed line between the filter & the RH injetor – I actually added a gauge inline, like guys do with carbs. I forget the stock PSI (13?). I can try to look when I get home, but my 82 TA manual is in many pieces now thanks to CFI. I’m not sure I could find the page.

Vacuum leak.
Injectors
Coolant temp sensor.
Map Sensor
Bad fuel pressure regulator (in rear TBI unit)
Bad IAC <-- I had these kick my butt for months – parts store gave me wrong one with wrong pintle cap.
Throttle Position Sensor

Look here too:
http://www.aces.edu/~gparmer/efi/
http://www.x-ram.com/commonproblemswithcrossfireonlyinjectionsystems.html
I also have a link to a CFI forum at home, that I can get you.

Prowl EBay for manuals, really any 82-84 Camaro or Firebird would do (probably more useful then the vette one). A paperclip & multimeter can go a long way. Or a used OTC or similar scanner. When we upgrade our scanner at work, I used to drive around with the old one plugged in, just to see what was going on.

Former mid 13 sec CFI Trans Am owner. I might get another one someday, just to prove people wrong. I’m sure I could dip it in to the 12’s now.

 

[kustomwerker]

you`re in a slim croud bonzo, but it sounds like you`ve had way more dealings with them than i...thats why this forum is so cool...

 

[BonzoHansen]

Well, I was in college and felt ballsy enough to take it on. TPI was still new then. And CFI flat looks cooler. And when the throttle bodies are bored out to 2" each, they sound better too. I'll say this, after getting that to run well on a consistent basis, it gave me confidence to take on most anything car related.

http://www.crossfire.homeip.net/


Now I am getting ready to put and LS1 in my 67...things never change....at least now I'll have lots of aftermarket support. I had almost none then.

Did Mr Getz leave us?

 

[novaderrik]

how do you make any power with a crossfire setup?
those intake ports in the manifold are only about 1"X1".

 

[wiskeesour]

Built a 305 with a 350 crank and put a CFI system on it. Did like what Bonzo stated and bored the throttle bodies and installed aftermarket injectors...thing was a screamer....I like CFI...may build again someday.

 

[novaderrik]

Built a 305 with a 350 crank and put a CFI system on it. Did like what Bonzo stated and bored the throttle bodies and installed aftermarket injectors...thing was a screamer....I like CFI...may build again someday.

so, you built a CFI 305? 305 and 350 have the same stroke crank..

sorry for digging up an older thread, but i've been looking at a CFI 83 Z, and did a search just for giggles..