i have put a new performance 350 in my car and i want to know if what i need to do to my computer carb. I replaced the metering rods and adjusted the av flap seems to run good. but a performance mechanic told me that my car will always run lean and i can't do any thing cause of the computer controlled primary circuit.I am going to pay the seventy bucks and have it dynoed and check the air fuel ratio.Can any one help?

Dave

 

I dont know about lean, It should be fine, but the timing curve adjusted by the computer isnt exactly "High Performance" and can barely mange on a 305. Thats the only major draw back I see for a 305 to 350 swap.
SSC

------------------
85 Camaro, 355/400 "drag car" in moth ***** 13.1@ 101mph on its last season run.
Plans: Possibly add N20 for next season.
82 Firebird, 305/350 currently moth balled.
Current plans: Rebuild 305 with flat tops instead of the dished "cups" for pistons or slightly built 327 with the 58cc heads from the LG4, Upgrade the 2:73 to 3:73 or 3:42 and replace the turbo 350 with 700r4.


"Web site under construction"

G0D Bless.

 

when i go wot it seems to have a big flat spot out of second gear (i have a 5 speed) at about 3000 rpm seems to still haul *** .
Is there any way to upgrade the computer for an 84 camaro with a stick I know you can do it with a automatic I bought the ecm,esc and the knock sensor for the zz4 conversion kit but it throws the check engine light.so i switched chips but it does the same thing.only the original ecm and chip are ok.

Help please.

 

If it's laying down immediately after shifting into 2nd it's likely you have inadequate fuel supply. Hook up a fuel pressure guage in the fuel line as close to the carb as possible. Duck tape the guage to the windshield (temporarily!). Make a run. Fuel pressure should be consistent even at WOT/high RPMs. If it takes a "nose dive" at the top of every gear then you don't have adequate fuel supply.

What your mechanic told you is not correct. The ECM only adjusts the A/F ratio at part throttle and idle, based on readings from the O2 sensor to maintain a 14.7:1 A/F ratio (good emissions and economy). At WOT throttle, however, you can adjust the A/F ratio the conventional way- changing metering rods, etc. The ECM doesn't try to adjust things at WOT.

The stock ECM and chip can run things just fine. Just bump up the initial timing about 4* over stock (6* to 10*) and it'll work just fine. I wasn't even aware the ZZ4 conversion kit came with all extra stuff.

Whatever you do, make sure you don't have the check engine light popping on. It'll run in "limp home" mode and give you terrible performance and economy.

 

Damon

Thanks for the reply I just got the car together and i love it.That mechanic scared me. I know the car is running great just flat spot i will check the fuel pressure like you recommended.You can see the whole zz4 conversion kit on line at one of the big dealers i forget the name started with an s.also i did a swap of all the electrical parts they recommended the 350 knock sensor and the esc work fine but when i put in the other ecm it lit the engine light even if i switched back to the old chip.I think i am going to read the tech article on the cc carb again and see if i can adjust the primary circuit a little.