I 've '83 Z28 305 Camaro with a brand new Holley 600 cfm a Holley performer rpm intake mainfold,dynomax exhaust.My problem is that i don't have any power between 2,000 and 5,000rpm . My car is slow like a L4.I can't figure out what's going on.I 've checked the throttles and seems to be fully opened,the cylinder compression presure is fine.

IT'S SO FRUSTRATING HELP ME

 

welcome to thirdge.org you didn't give much information, the first thing i'd do is make sure the tune up is good and it sounds like you just changed the intake and carb so i'd check for vacuum leaks and tune the carb.

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ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM

 

Federico,

Welcome aboard!

Your lack of power in the middle and upper RPM range may be due to a carburetor flow mismatch or the carburetor tuning. Most Holley carbs come out of the box set up for a very large range of applications and need tuning before they operate correctly.

What model/type Holley did you install? If it has vacuum secondaries, you may need to install a different secondary vacuum servo spring to control the secondary throttles at a correct rate for your engine. You may also have to change the power valve and main jets to something appropriate for your displacement.

In other words, the carburetor may require tuning to your engine.

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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

What distributor is on it? Which engine is it? What exhaust is on it?

That's a really big intake manifold for a 305. In order for it to work right, the other parts of the engine having to do with flow need to be enlarged to match it. If your engine is the LG4 it desperately needs an entire exhaust system and a cam.

The computer-controlled distributor needs to be replaced since you now have a non-computer-controlled carb on it. The computer isn't seeing all sorts of things (like a throttle position sensor for example) that it needs to accurately control the ignition timing. If you leave that on there, you will end up with a generally sluggish car, no throttle response, etc. because there will always be too little timing advance.

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"So many Mustangs, so little time..."
ICON Motorsports

 

the carb(it's a vacuum secondary) and the mainfold was already in the car when i bought it so i think that the carb is tuned correctly but i don't know much about the vacuum servo spring and the power valve ,what can i do to know if my setup is ok.
I took to a competent mechanic here in Itlay and he told me that the carb is tuned correctly but i don't becouse the car doesn't work

 

OK i've foun out a couple of things:

-my spark plug has a very small gap instead of the .045"
-when i lowered the tv-cable bracket the car was very fast(as it should be) but won't changes to upper gear(only full throttle shifts).

what can i do to reconize if the distributor need to be replaced?

ANY HELP IS REALLY APPRECIATED

 

I am not sure about an 83, but is your car computer controlled. I know my 86 was and I got a new motor with a Non Computer Controlled distributor and was running the stock Computer controlled q-jet. Since the distributor is no longer CC, it causes errors, the only of which I know is horrible gas milage and causing the car to run extremely rich. I was getting 10mpg, I bought a new carburetor NON cc, and am no longer using my ECM.
If you're using the stock distributor you need to get a NON cc one.

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'86 IROC
T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK TES HEADERS
FLOWMASTER, NO CAT
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat
2:73 GEARS
Rebuilt 700R4, with manual valve body
B&M Megashifter, 5" Autometer Tach w/shift lite
Soon to be installed
3:73 Richmond Gears and 3" Hooker Aero Chamber
Corvette Servo & .500 boost valve
15.61@ 95.2mph G-Teched, 1-2 shift slippage, and just replaced a burnt plug wire
"There is nothing more addicting than speed"

 

the car is a no computer controlled since new.
Tomorrow i will get new plugs i hope to fix this problem it' so frustarting i don't have absolutely no power from 2,000 to 5,000 rpm .

 

HEllo anyone had the same problem ...i need some suggestion please, i'm a poor italian guy with an american dream in my heart that needs to be fixed up

S.O.S

 

Look at the distributor, and see if it has a vacuum diaphragm on it. This would be a large silver can off to one side of it at the bottom, with a vacuum line running to it. If it doesn't, get a new one. MSD makes one that's good but doesn't cost too much. There's a vacuum port on the carb specifically for hooking up that distributor part.

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"So many Mustangs, so little time..."
ICON Motorsports

 

The vacuum diaphragm is on its place.

I' ve just finished to check the distributor an is in perfect conditions so i guess thats must be a carb or plugs gap problem.

Now what kind of plugs will be best for my type of engine?