I have a edelbrock 750 and this weekend I want to hopefully dial in my carb to work with my new engine. Right now I'm pretty sure it's a bit out-to-lunch. I've been changing stuff around per what the plugs have been showing.

but the engine has a lean spot from off-idle to wot and warm start up's require quite a bit of cranking.

I tryed doin as the manual says, to time my rpm sweep with a stopwatch, but i can never get a consistant number to base any gains or losses.

My thoughts were to jet until I get a good reading on my spark plugs and then iron out any lean spots, idle quality, startup quality with that particular jet/rod combo.

Is this a good idea? I'm kind of a newbie with carbs so any advice would be appreciated.

Also, if any of you are using the same combo as me, is there anything you've found that works real well?

my mods are in my sig.


----------------------

Jeremy
1982 Camaro "VortecZ"

Carbed Vortec 350 with stock Vortec heads
Edelbrock rpm intake, 750 carb
accel ignition, dynomax headers, Comp cams xtreme energy 262H,
richmond 3.73's, powertrax locker, 700r4 w/ shift kit, stock converter
and other useless crap.

I AM.
Canadian

 

I'm sorry we don't help out Canadians around here.

Just kidding.

Just some general rules of thumb:

1. Fix any problems. No kidding, right? If you don't have consistent fuel pressure throught the RPM range (are you SURE you do?)or the ignition advance curve/timing isn't right you'll never get it running right. You'd be surprised how many carb problems are found in the ignition!

2. Check the float levels. Set them to spec.

3. NOW start tuning the carb. First off, put it all back to stock jetting/settings. You DID write down the stock settings, RIGHT? If not, call Edlebrock and get them to help you. WRITE DOWN EVERY CHANGE ON A PIECE OF PAPER. Make it a habit.

4. Change primary jetting first, then accelerator pump setting, then the secondaries. Make small incremetal changes- 2 jet sizes at a time, no more.

5. I often find it VERY helpful to simply disconnect the secondaries completely until you get the primaries dialed in. If you do this you only care how the engine performs up to about 3500 RPMs. You only have to worry about getting the primary jets/rods and the accelerator pump right without having to worry about the added tuning complication of getting the secondaries right at this point. Get it?

6. Reconect the secondaries and play around with their jetting.

7. Last thing to play with is the secondary tip-in RATE. How fast the seocondaires open up, but by this point it should be running a bunch better already even without messing with that.

OF course, once you get through the first round of changes you have to go back for a second, third, fourth round, etc. to get it really dialed in, but one-two rounds though should get you pretty close.

That's how I do it, anyway.

 

Thanks a bunch, yea I wrote down all my changes in the "log book" edelbroke gave me.
I have my timing all set and I'm possitive my ignition is 100%. but how do I check for fuel pressure? I spose I need an in-car guage and then run it through gears? also
would a air/fuel guage be a good asset? are they accurate enough for precise tuning?

thanks for you help, I'm going to print your post