Ad Radar
Item Posts    Sort Order

350 RUNNING RICH

 
dougnholly
I love my Chevy Chevette!
Posts: 1
Joined: 08/13
Posted: 08/30/13 05:59 AM

I bought this 79 elcamino It has a newer motor in it late 80s. 600 edelbrock running rich. float level is good went through the carb got a strip kit no changes.it wont even brake torque.after i take off maybe 10 ft and i stomp the pedal secondaries kick in it goes like gang busters. iwas thinking cam not sure but trial and error will speak for itself.any suggestions or recomendations would be appreciated. Thanks.  

Post Reply
zman123
Everything in my driveway’s a Chevy
Posts: 537
Joined: 06/08
Posted: 08/30/13 06:40 AM

Have you checked the jet and metering rod size? Go to the edelbrock website and there is a section on carb tuning, that should get you on the right track. What kind of fuel pump are you running? If it's got an electric fuel pump you may be getting too much fuel pressure which will push fuel past the needle valves  causing flooding (or running too rich) Over 6 psi is too much for that carb.  

Post Reply
dougs1979
I love my Chevy Chevette!
Posts: 6
Joined: 08/13
Posted: 09/02/13 07:27 AM

Well regulated fuel pressure and still no change still running rich.Looks like I,ll be changing cams.I really dont like the stock sound any way theres no rumpidy rump any how.The heartbeat just isnt right.I,ve had other sbc,s that have run like raped apes that,ll burn,um all the way through the gears.My brother has a lifted 1500 5.7 vortec off the line he,ll leave me 2 truck lengths until wide open throttle and secondaries kick in by that time race is over.  

Post Reply
waynep712222
I have an SS396 tatoo
Posts: 251
Joined: 03/13
Posted: 09/02/13 01:05 PM

if its running rich....


take the top back off the carb...

remove each of the boosters one at a time and clean the air bleeds... verify that you can go thru each one with something like a single bristle from a wire brush....


do not change the size of the openings.. only verify they are clean..

AFB AVS Airbleeds Zps9b83323f

these holes are SO small that any dirt will clog them..  if they are clogged..  you will get a rich air fuel mixture... and the car may not have the power you expect...

clean.. clean, clean...    do you run an air filter???  do you have an air cleaner mounting gasket installed to prevent dust and dirt from getting under the air cleaner where it mounts to the top of the carb...  

Post Reply
68scott385
I mow my lawn and find Chevys
Posts: 1994
Joined: 10/09
Posted: 09/02/13 10:35 PM

Have you set the idle air screws to get the highest vacuum reading at idle? What about the step-up springs? Have you used the correct ones for your application?  
68scott385 68scott385 68scott385

Post Reply
68scott385
I mow my lawn and find Chevys
Posts: 1994
Joined: 10/09
Posted: 09/02/13 10:36 PM

Edelbrock carb owner's manual.

http://www.edelbrock.com/automotive_new/mc/carbs_acc/pdf/carb_owners_manual.pdf  
68scott385 68scott385 68scott385

Post Reply
dougs1979
I love my Chevy Chevette!
Posts: 6
Joined: 08/13
Posted: 09/03/13 05:25 AM

Thank you That is what I,ll do next. That sounds about right when I got the car there wasnt an air cleaner and I pulled the carb apart but didnt exactly get nitty gritty like that just made sure fuel orifices were clear.  

Post Reply
dougs1979
I love my Chevy Chevette!
Posts: 6
Joined: 08/13
Posted: 09/03/13 06:04 AM

Thanks for the edelbrock link. I will go through that also. The info I have been given will be most helpful thanks.  

Post Reply
dougs1979
I love my Chevy Chevette!
Posts: 6
Joined: 08/13
Posted: 09/08/13 07:53 AM

ok I went through the carb with a fine tooth comb went through the distributor changed out sparkplugs,got nitty gritty.The only other thing I can think of or would make sense would be cam to crank timing could be off a tooth while Im there I will put this other cam in.I really am hoping the cam crank timing is off for heaven sakes its a light ass end elcamino it should blow the tires off.  

Post Reply
waynep712222
I have an SS396 tatoo
Posts: 251
Joined: 03/13
Posted: 09/08/13 08:57 AM

Changed out sparkplugs, got nitty gritty.   i am taking the spark plugs were covered in carbon....

a few things.. do you have a vacuum gauge you can hook to manifold vacuum..

hook it up and slowly raise the engine speed... to around 3000 rpms...

as you increase engine speed slowly.. the manifold vacuum SHOULD NOT drop as you increase in speed..  if it drops you have a blocked exhaust....

do you have factory exhaust with a heat riser valve in the passenger side.. is there vacuum to the actuator??? if thats disconnected or the vacuum hoses are leaking.. it will pull the heat riser valve. trap door closed on that manifold.. causing you unseen issues..


do you have cats in the exhaust also.. the manifold vacuum test will show if those are restricted..

~~~~~~~~~~~~~~~
if there was a LOT of crud on the spark plugs..  do you feel daring..??? do you have some skills... do you have a clean plastic soda bottle laying around..  wash it out .  poke a very small hole in the center of the cap.. so it squirts a fine stream of water.. or a fine spray...  warm up the engine till its hot..   take the engine speed to around 3000 rpms..   trickle some water via the tiny hole into the primary carb throat...  you don't want to swamp the motor.. you want to add a tiny amount as it will get into the combustion chamber... turn to steam and blow the carbon off the chambers...  this takes a about 2 minutes of running squirting.. then stopping the squirt while the engine recovers and clears out..  never stalling the engine.. never POURING a lot in..  as you can completely destroy the motor doing this if you get too much water into the engine..

the reason to do this at 3000 RPMs... so the water does NOT puddle in the intake.. where it will build up and cause a hydraulic lock, break your pistons.. bend your rods.. break your crank..  kill your wallet..  and an additional warning.. this can blow the carbon into ash.. and clog the cats... so i have just tossed you a butterfly knife. and its spinning fast in the air.. its up to you to catch this and use this without drawing blood from your motor .. or green from your wallet...

i usually don't post this info as its way dangerous.. and after you have replied.. i am going to come back and delete this section..

now... lets get back to the carb....

engine idling.. turn the idle mixture screws in individually.. then back out .. can you make the engine stumble at idle..??? do you have idle mixture authority???

yes.. or no.... when you had the carb off.. were you able to flip it over.. hold the choke open... hold the fast idle cam open.. allowing the primary throttle blades to come to a stop on the idle speed screw tip ONLY... and see that the idle transition slots were just barely uncovered...

Idle Transition Slots Setting Zps7bcc767a
and yes.. thats a holley.. same thing on an edelbrock...  carb operation works the same via all brands and models..

idle circuit..
.....------idle transition circuit
...................----------primary main circuit---------------------------
........................................------------secondaries-------------

see the overlap in fuel delivery... -----------  dashes are overlap.. periods are not..

if you have the idle speed turned up to expose too much of the idle transition slots.. you will have too much fuel at idle ..  

Post Reply
dougs1979
I love my Chevy Chevette!
Posts: 6
Joined: 08/13
Posted: 09/09/13 03:50 AM

Yes did all that! and yes more than daring and willing to try anything I have around 17 inches or so vacuum.no flapper valve.my Dad is an old pontiac tech from san diego back in 66 when tri power was the thing.He showed us how to loosen up sticky valves release carbon,not be afraid of firing up motors on our shop floor as me and my brothers held it down blue and orange flames shootin a foot out of each side.everything is in proper working order there arent any cats its a bone stock tbi motor now with a carb and intake.  

Post Reply
dougs1979
I love my Chevy Chevette!
Posts: 6
Joined: 08/13
Posted: 09/09/13 03:52 AM

Yes did all that! and yes more than daring and willing to try anything I have around 17 inches or so vacuum.no flapper valve.my Dad is an old pontiac tech from san diego back in 66 when tri power was the thing.He showed us how to loosen up sticky valves release carbon,not be afraid of firing up motors on our shop floor as me and my brothers held it down blue and orange flames shootin a foot out of each side.everything is in proper working order there arent any cats its a bone stock tbi motor now with a carb and intake.  

Post Reply
TO TOP