Holley 870 street avenger help. - Chevelle Tech
Chevelle Tech join team chevelle as a supporting member  
Chevelle Parts at SS396.com      
GROUND UP & SS396.com         
Official Sponsor of Team Chevelle
     

Auto Insurance

Chevelles.com is the premier Chevrolet Chevelle Forum on the internet. Registered Users do not see the above ads.
Engine AdvertisementGeneral Engine Discussion.

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old Feb 24th, 09, 8:26 PM
90454SS 90454SS is offline
Tech Team
 
Join Date: Jul 2005
Location: ca
Posts: 44
Default Holley 870 street avenger help.

Hello, i got a rich prolem with this carb 870 street avenger, i dont know anything about carbs but im learning, if the transfer slots are exposed to mutch will this be the couse of runing rich, here are some pics that i took fron the bottom of the carb.
The carb is out of the box, with the power valve is 4.5 and jets i think they are 78 primarys 82 secc.

My engine is a 454
3964290 heads 2.19 1.88 valves, flat top pistons, rpm air gap intake and cam is voodoo 60204 Duration 276/284, Lift .554/.572, msd 6al distributor and coil, i know this cam got to have a lot of timing advance for it to idle.
But any help is welcome.
Thanks.





And one from the top

Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old Feb 24th, 09, 9:39 PM
70-SS454 70-SS454 is offline
Senior Tech Team
Frank Riley
 
Join Date: Feb 2006
Location: Lenexa (KC), Kansas
Posts: 3,510
Default Re: Holley 870 street avenger help.

Is the power valve blown, first thing I'd check with a holley that has a rich condition, but I thought the Street Avengers were a new enough design to have a power valve relief check valve circuit... but just a thought...
__________________
70-454 LS5
Mid America Chevelle Club #293
Greater Kansas City
Reply With Quote Quick reply to this message
  #3  
Old Feb 24th, 09, 10:56 PM
mirage2991 mirage2991 is offline
Tech Team
JB
 
Join Date: Mar 2008
Location: SC
Posts: 608
Default Re: Holley 870 street avenger help.

I have the same problem on a different brand carb...
looks like you might have a tad much slot exposed...try more timing at idle or lock your dist at you max timing. Has done this before? did you buy the carb new? If you can give us more info about the history behind the problem that would be a plus.
__________________
69 Camaro SS, Black on black
489 ci 10:1

1968 corvette convertible 327/4 speed

2011 ZR1 Arctic White w/black headlights
Reply With Quote Quick reply to this message
  #4  
Old Feb 24th, 09, 11:20 PM
bbmusclecars427 bbmusclecars427 is offline
Senior Tech Team
Howard
 
Join Date: Feb 2007
Location: Va.Beach,Va.
Posts: 1,080
Default Re: Holley 870 street avenger help.

According to my holley catalog,you are correct with 78 primary,82 secondary jets with a 4.5 powervalve directly out of the box.I agree with others in saying that more info is needed as far as your "burning rich" history,whats your initial timing,total timing? Even though you do have a backfire relief valve built-in from holley...was there a backfire through the carb after the install of the 80870? Vacuum advanced distributor? What is your manifold vacuum reading? What type,CFM,primary jet size carb were you running before?
__________________
Just Having Fun With All My Chevy Big-Block Toys ( OO ------SS------ OO ) ACES # 8687
ttp://s392.photobucket.com/albums/pp10/bbmusclecars427/
Team Chevelle #5242
Top 3 70' Chevelle modified
@ Chevellabration 09'
june 2010 Chevelle World magazine
Reply With Quote Quick reply to this message
  #5  
Old Feb 25th, 09, 1:08 AM
90454SS 90454SS is offline
Tech Team
 
Join Date: Jul 2005
Location: ca
Posts: 44
Default Re: Holley 870 street avenger help.

The carb was new when i put it on the engine, and it was rich fron the first time.
My initial timing is 15 and total 36.
O and in the past i had maybe 3 backfires.(going to change the powervalve)

I have Vacuum advanced distributor, im going to lock the dist and see if it helps.
and change the primary jets to 76.
Reply With Quote Quick reply to this message
  #6  
Old Feb 25th, 09, 1:36 AM
Tom Mobley Tom Mobley is offline
mod since about forever, old now :)
TerribleTom II
 
Join Date: Oct 1998
Location: Glendale, Az
Posts: 21,368
Default Re: Holley 870 street avenger help.

changing the main jets won't help with an idle problem. Do you have a WBO2 meter hooked up? What exactly is telling you it's rich?
__________________
Tom
Reply With Quote Quick reply to this message
  #7  
Old Feb 25th, 09, 5:40 AM
GRN69CHV GRN69CHV is offline
Team Member
Joe
 
Join Date: Nov 2003
Location: Thornton, Pa
Posts: 12,590
Default Re: Holley 870 street avenger help.

If you get response from adjusting the idle mixture screws, it is not open too far. I played with a rich idle condition on another 870 and only relief I got was to drill two small holes in the primary butterflies. You can try cracking the secondary blades, but do not expose the transfer slot or it will suck in fuel from the rear.
__________________
Status: Car-Less

http://www.chevelles.com/showroom/sh...2/limit/recent
Reply With Quote Quick reply to this message
  #8  
Old Feb 25th, 09, 7:07 AM
69-CHVL 69-CHVL is online now
Senior Tech Team
Vinny Vince
 
Join Date: Jun 2003
Location: Thornton, Pa
Posts: 12,340
Default Re: Holley 870 street avenger help.

Is the choke engaged when taking that photo?
__________________
*69 CHEVELLE SS EFI 502/T56/3.90
*06 C6 LS2/T56
*96 Stang LS/6.0 turbo - everyone should have one!
Reply With Quote Quick reply to this message
  #9  
Old Feb 25th, 09, 12:01 PM
90454SS 90454SS is offline
Tech Team
 
Join Date: Jul 2005
Location: ca
Posts: 44
Default Re: Holley 870 street avenger help.

What exactly is telling you it's rich? black smoke, smell fuel, and the plugs are wet and black.

and i get a response from adjusting a idle mixture screws, if in to far it will die, if i get them out to much it wil rev a little i think.
And i the remove the choke.
Reply With Quote Quick reply to this message
  #10  
Old Feb 25th, 09, 3:58 PM
GRN69CHV GRN69CHV is offline
Team Member
Joe
 
Join Date: Nov 2003
Location: Thornton, Pa
Posts: 12,590
Default Re: Holley 870 street avenger help.

Make sure the secondaries are not open too much also. Did you check the float levels? How about fuel filters? Sound to me like there could be something in the needle/seat - either front or rear. What fuel pump? Did you check the fuel pressure at idle?
__________________
Status: Car-Less

http://www.chevelles.com/showroom/sh...2/limit/recent
Reply With Quote Quick reply to this message
  #11  
Old Feb 25th, 09, 4:31 PM
90454SS 90454SS is offline
Tech Team
 
Join Date: Jul 2005
Location: ca
Posts: 44
Default Re: Holley 870 street avenger help.

whith the clear sight plugs i can see the fuel just peaking, i have one fuel filter just after the fuel tank, another just past the fpr.
The fuel pump is an electric one and the fuel pressure is 6.5psi at idle, should it be 5psi?
Reply With Quote Quick reply to this message
  #12  
Old Feb 25th, 09, 4:46 PM
GRN69CHV GRN69CHV is offline
Team Member
Joe
 
Join Date: Nov 2003
Location: Thornton, Pa
Posts: 12,590
Default Re: Holley 870 street avenger help.

6.5psi is fine. You sure plugs are wet with gas and not oil?
__________________
Status: Car-Less

http://www.chevelles.com/showroom/sh...2/limit/recent
Reply With Quote Quick reply to this message
  #13  
Old Feb 25th, 09, 4:51 PM
1965_SSChevelle 1965_SSChevelle is offline
Tech Team
Greg
 
Join Date: Jan 2006
Location: Catlettsburg, Ky
Posts: 239
Default Re: Holley 870 street avenger help.

I had the same problem with a 780 Street Avenger and never did get it worked out. I sold it and bought a 4150 DP and never looked back.
__________________
1965 Chevelle
Reply With Quote Quick reply to this message
  #14  
Old Feb 25th, 09, 6:20 PM
SS402 SS402 is offline
Tech Team
George
 
Join Date: Dec 2008
Location: Lakeland, Florida
Posts: 416
Default Re: Holley 870 street avenger help.

Quote:
Originally Posted by 90454SS View Post
Hello, i got a rich prolem with this carb 870 street avenger, i dont know anything about carbs but im learning, if the transfer slots are exposed to mutch will this be the couse of runing rich
yes, the transfer slots should be exposed no more than .020", when you expose too much of the transfer slot you effectively bypass the idle circuit..
__________________
Powered by Rat
Monte pics
video http://videos.streetfire.net/video/S...a-988001310582
Reply With Quote Quick reply to this message
  #15  
Old Feb 25th, 09, 7:30 PM
90454SS 90454SS is offline
Tech Team
 
Join Date: Jul 2005
Location: ca
Posts: 44
Default Re: Holley 870 street avenger help.

Yes the plugs are wet with gas not oil, i put one clean plug i run it for less then a minute and half of the plug was black and with the smell of gas.

And If oil was in there white somke will be out of the exhaust rigth?

Ok here is what im going to do, check for blown power valve, double check timing, float level and fuel psi, clean the carb and im thinking on locking out the distributor, and see if i can get the transfer slots to .020" or less ,but i will do this on sunday.
Thanks.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply
Chevelle Tech > Mechanical > Engine      Current Topic: Holley 870 street avenger help.
Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Chevelle Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address. Note, you will be sent a confirmation request to this address.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 5:18 PM.


Is there a site like this for?    El Caminos Camaros Novas Impalas GTO Chevy Punch All Chevys

2009 Team Chevelle - AutoForums