Today's Posts Mark Forums Read Calendar
Go Back   NJFBOA - Home of New Jersey's Camaros and Firebirds > Tech Forums > Engine / Power / Tuning

Notices


Reply
 
Thread Tools
Old 08-18-2008, 06:34 PM   #1
chrisfrom nj
 
chrisfrom nj's Avatar
 
Join Date: Feb 2005
Location: west orange nj
Posts: 2,415
iTrader: (8)
car stumbes at 3,000 rpm

i recently converted my car from tbi to carb i changed everything intake, carb, dist, now at around 3,000 rpm it sumbles a little the carb is a holley 650 the dist is a msd it has a vacume advance,and the intake is a team g intake it allso has a 2 inch spacer please help me fix my car
chrisfrom nj is offline   Reply With Quote
Old 08-18-2008, 06:43 PM   #2
bubba428
 
bubba428's Avatar
 
Join Date: Jan 2007
Posts: 5,623
iTrader: (0)
turn you distributor clockwise about 4 degrees timing (thats 2 degrees on the dizzy), and richen the mix just a little bit....then use the throttle set screw to hold the motor at 2000rmp and adjust the timing. counter clockwise till it runs crappy then clockwise till its smooth. then with it still at 2000rpm turn you adjustment screw in the same maner tighten till it stumbles and loosen till its smooth. repeat as necessary. there are better more exact ways but thats the best way for a quick tune by ear.

Did I miss anything?.......


O check all your vacuum lines for cracks and other leaks...I think you may be either lean or to far advance...do what I said, that should get you closer to 100% depending on your ear
__________________
2000 Tahoe Z71 5.7
1982 Z28 Pacecar 305
1999 S10

Last edited by bubba428; 08-18-2008 at 06:51 PM.
bubba428 is offline   Reply With Quote
Old 08-18-2008, 10:35 PM   #3
chrisfrom nj
 
chrisfrom nj's Avatar
 
Join Date: Feb 2005
Location: west orange nj
Posts: 2,415
iTrader: (8)
Quote:
Originally Posted by bubba428 View Post
turn you distributor clockwise about 4 degrees timing (thats 2 degrees on the dizzy), and richen the mix just a little bit....then use the throttle set screw to hold the motor at 2000rmp and adjust the timing. counter clockwise till it runs crappy then clockwise till its smooth. then with it still at 2000rpm turn you adjustment screw in the same maner tighten till it stumbles and loosen till its smooth. repeat as necessary. there are better more exact ways but thats the best way for a quick tune by ear.

Did I miss anything?.......


O check all your vacuum lines for cracks and other leaks...I think you may be either lean or to far advance...do what I said, that should get you closer to 100% depending on your ear
thanks bubba im going to try that tomorrow
chrisfrom nj is offline   Reply With Quote
Old 09-14-2008, 06:26 PM   #4
chrisfrom nj
 
chrisfrom nj's Avatar
 
Join Date: Feb 2005
Location: west orange nj
Posts: 2,415
iTrader: (8)
my car still stumbles and cuts off at wot
chrisfrom nj is offline   Reply With Quote
Old 09-17-2008, 02:00 PM   #5
crainholio
 
Join Date: Nov 2004
Location: Randolph
Posts: 198
iTrader: (2)
What jet size are you running in the primary metering block? Secondary block?

What power valve # are you running?
__________________
1982 Z28 w/ '01 LS1 + T56, TR224 cam, Katech oil pump, JWIS chain
crainholio is offline   Reply With Quote
Old 09-17-2008, 04:41 PM   #6
chrisfrom nj
 
chrisfrom nj's Avatar
 
Join Date: Feb 2005
Location: west orange nj
Posts: 2,415
iTrader: (8)
the stock jets that the holley 650 came with
chrisfrom nj is offline   Reply With Quote
Old 09-19-2008, 03:38 PM   #7
crainholio
 
Join Date: Nov 2004
Location: Randolph
Posts: 198
iTrader: (2)
Quote:
Originally Posted by chrisfrom nj View Post
the stock jets that the holley 650 came with
I guess it's possible that Holley sells a carb properly jetted for your exact engine. But that hasn't been my experience.

The mixture adjustment screws on the metering block only fine tune, if the jets aren't properly sized the screws can't make up the difference.

Time to pull & read your spark plugs, or hit the dyno with a wideband O2 rig. After you've used a timing light to properly set your distributor to 8deg BTDC advance w/ the vacuum advance capped.
__________________
1982 Z28 w/ '01 LS1 + T56, TR224 cam, Katech oil pump, JWIS chain

Last edited by crainholio; 09-19-2008 at 03:40 PM.
crainholio is offline   Reply With Quote
Reply

  NJFBOA - Home of New Jersey's Camaros and Firebirds > Tech Forums > Engine / Power / Tuning

Thread Tools

Posting Rules
You may not post new threads
You may not 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

» Sponsor List














All times are GMT -5. The time now is 10:47 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.